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DIY Stompboxes => Building your own stompbox => Topic started by: J0K3RX on September 01, 2012, 02:49:40 PM

Title: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 01, 2012, 02:49:40 PM
I thought I would give this a try and I am damn glad I did! I used the original Uberschall tube amp schematics that I found by accident while looking for something else... This thing is a beast, butt loads of high gain!! 

I made a few changes here and there but for the most part it's true to the schematic. I removed a resistor (470k) going to the volume pot because the volume was a little too low. I added a gain/saturation boost switch and of course the diodes between source and gate on Q2, Q3 and Q4 and that's about it. You may want to experiment with different value pots in the tone stack.. I went so far as to use the same values used on the Dr. Boogie and I may leave it like that, still trying to get it just right...  When converting these high gain preamps over to JFET it seems like the tone stack does not make the transition as well as it should. Probably because of the lower voltages? Anyway, the Dr. Boogie values or close variants seem to work pretty well.

It should be biased between 4.5V and 5v to your liking...

And no, I did not create a schematic... If you want the actual amp schematic PM me and I will send it to you.

(http://dl.dropbox.com/u/11178619/Black%20Forest%20Rev1%20-%20Small.png)

http://dl.dropbox.com/u/11178619/Black%20Forest%20Rev1.png   <--Larger image, easier to read.

Board transfer
http://dl.dropbox.com/u/11178619/Black%20Forest%20Rev1.pdf
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 01, 2012, 05:55:37 PM
Thanks for posting this, it looks very interesting! How does it sound compared to the Dr boogie?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 01, 2012, 08:16:02 PM
Thanks for posting this, it looks very interesting! How does it sound compared to the Dr boogie?

Well, this is a component for component scaled down copy of the Uberschall Twin Jet super high gain lead channel where as the Dr. Boogie is a component for component copy of the Mesa dual rectifier lead/Red channel... This seems to have more gain, more mids and a lot of clarity on the bottom end, not muddy at all! Great for 7 and 8 stringers, lots of low end punch and explosive chords! Great for 6 string also, just an amazing amount of usable gain...

It doesn't sound at all like the Dr Boogie.. This is a different beast! Same as both amps are different.

If you like the Seventheaven Bogner Ecstacy copy by GoosoniqueWorx this thing spanks it and sends it to bed without dinner :icon_twisted:

I will try to post some sound clips and maybe some pics of the guts...

Next on my list is the Soldano Avenger :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: John Lyons on September 01, 2012, 08:42:59 PM
Nice...if you post some clips I'd like to have a listen. Thanks  :icon_biggrin:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 02, 2012, 12:00:00 AM
Nice...if you post some clips I'd like to have a listen. Thanks  :icon_biggrin:

+1
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: tyzjames on September 02, 2012, 03:45:57 AM
Very interesting, thanks for posting! Would love to build it and compare it with the Seventheaven!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 02, 2012, 01:42:34 PM
Sorry, still working on getting some time to myself (without everybody up my ass) to make some sound clips! :icon_evil:


If anybody has any ideas for different tone stack feel free to share! I would prefer less knobs also... I added the presence knob, that could easily go away! Less may be more in this case... more control over the tone??
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: meffcio on September 02, 2012, 02:19:04 PM
Sorry, still working on getting some time to myself (without everybody up my ass) to make some sound clips! :icon_evil:


If anybody has any ideas for different tone stack feel free to share! I would prefer less knobs also... I added the presence knob, that could easily go away! Less may be more in this case... more control over the tone??
As I said to you in a PM, I'm gonna experiment a bit when I finish my exams. I think of shrinking the eq to like 2 knobs and a switch, or something. The casual bass and treble control + presence boost, or maybe a tone stack similar to the Proco Solo. Need time, breadboard, and we'll see what happens then. ;)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 02, 2012, 04:07:40 PM
I'm not qualified to make any changes to your layout, but I am definitely a stickler when it comes to heavy gain. I also have a friend with the "real" Uberschall, so I should be able to get a good side by side comparison. In reference to what you said earlier... it sounds great as is, so I'll build it from your beta layout and give you an honest opinion based on my ears. Thanks again for your work on this, I'm psyched to try it!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 02, 2012, 10:27:26 PM
I'm not qualified to make any changes to your layout, but I am definitely a stickler when it comes to heavy gain. I also have a friend with the "real" Uberschall, so I should be able to get a good side by side comparison. In reference to what you said earlier... it sounds great as is, so I'll build it from your beta layout and give you an honest opinion based on my ears. Thanks again for your work on this, I'm psyched to try it!

I am gonna work on the tone stack tonight... needs some work! Whatever I come up with I will update here... That would be cool to do a comparison to a real Uber! Maybe your friend would let you plug it into the effects return of his real Uberschall, that would bypass the amps actual preamp and the pedal would become the preamp. That would really be a side by side comparison! :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 02, 2012, 11:01:24 PM
That's a great idea! And in the process, I can watch him get super pissed at me if it sounds just like it. I'll wait for you to post a layout you're happy with.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 03, 2012, 09:46:49 AM
Ok, this is what (mensur) another forum member sent me in a PM.

"Change source resistor on the buffer with 33K-47K-56K and see what will happen, the buffer cannot track cut-offed signal well and so tone stack becomes buggy."

So, I tried it and it made a BIG difference! Instead of the values he mentioned I tried 10k (Like the Dr.Boogie) and I am fairly happy with it... I may need to try his suggested values as well just to get it dialed in or maybe I will stick a 100k trim pot on there and adjust until I get just the right value :icon_idea:  

In short: What I did was I changed R16 from 100k to 10k... All the pots are stock value from my diagram.

I don't think I will be changing the layout since it's a direct copy of the amp.. however, I believe that I will be changing component values here and there to get it dialed in better. Especially if others start to build it and find improvements etc... I mean, that's what this forum is for right!?  :icon_wink:

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 03, 2012, 10:37:03 AM
Mensur made the Randall RG emu right? I was just reading a few posts regarding that layout because it was next on my build list. I think a trimmer could be a good idea so you can mess with it to find the "perfect" value. Either way, I can build this as is and experiment with different values for R16. Looks like I'm placing another parts order this week........
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 03, 2012, 12:35:23 PM
Ok, here's an idea :icon_idea: I use a TS808 in front of everything, preamps, amps etc.. Just gives it that extra "kunk" sound and feel for lack of a better word. It also drives the notes when doing leads etc.. I know many players that use them like this. Even though the preamp has plenty of gain this just seems to add the cherry on top of the sunday! I mainly use it as a clean boost where the level is almost all the way up and the drive is all the way down. So, what I was thinking is maybe add a Mosfet/Jfet boost circuit foot switchable in front of this preamp like on the Wampler Triple Wreck, not many parts involved and I could get rid of the Presence knob and put a switchable low pass or no switch to accommodate the additional boost knob/pot :icon_question: Thoughts?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 03, 2012, 01:16:05 PM
Sounds good to me since I use the tubescreamer the same way.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 03, 2012, 02:32:16 PM
Sounds good to me since I use the tubescreamer the same way.

Ok, next question.. Which boost circuit should I use? I kinda have my ideas but I just want to get some educated opinions first. I want it to be as close to or better than using the tubescreamer with the level cranked and the drive all the way down... Also I don't want to run into any funky squealing noises or pops etc..
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 03, 2012, 04:01:25 PM
The only one I know of is the AMZ booster:   http://www.muzique.com/schem/mosfet.htm
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: meffcio on September 03, 2012, 05:37:23 PM
You can put any kind of booster there, but the question is will any booster other than the TS maintain the Tubescreamer's abilities in front of the Black Forest. To be honest, I never played any TS, so I don't know the nature of that certain stompbox. I'm not sure if there are sound reasons for many people using it as a booster. Maybe a simplest unclean booster will do the task, or maybe the TS is really the only way to go.
Any experience with that subject, forum people?

Maybe we'll have to analyse what TS actually does in that certain booster setting. How much db of gain, how does it alter the tone, etc. It should be easy to recreate it with a simpler device then, w/o unnecessary controls.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 03, 2012, 11:35:36 PM
Here's a quick crappy demo, dry as a bone.. too much gain :-\

http://dl.dropbox.com/u/11178619/BlackForest2.mp3
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: meffcio on September 04, 2012, 03:45:13 AM
Here's a quick crappy demo, dry as a bone.. too much gain :-\

http://dl.dropbox.com/u/11178619/BlackForest2.mp3
What was the recording chain? I always make that as simple, as I can - guitar>effect>line input in the PC>some guitar cab impulses on reaper, using LePou LeCab plugin.
When I put your sample through some impulses it sounded better, you know. ;p
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: nightendday on September 04, 2012, 04:05:46 AM
Here's a quick crappy demo, dry as a bone.. too much gain :-\

http://dl.dropbox.com/u/11178619/BlackForest2.mp3
What was the recording chain? I always make that as simple, as I can - guitar>effect>line input in the PC>some guitar cab impulses on reaper, using LePou LeCab plugin.
When I put your sample through some impulses it sounded better, you know. ;p

No kidding, that sounds BEAST with the cab sims. I WILL be building this.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bancika on September 04, 2012, 05:49:04 AM
(http://dl.dropbox.com/u/11178619/Black%20Forest%20Rev1%20-%20Small.png)

that's one of the nicest layouts I've seen drawn in my diylc :proud: :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: sugonidamaso on September 04, 2012, 06:53:25 AM
Hmmm. Thinking to change my Dr. Boogie :icon_mrgreen:. What a heavy sound! Great work Jim! Thank you!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: danielzink on September 04, 2012, 07:15:10 AM

Why the jumper between R18 and C22 ?

Dan
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 04, 2012, 09:39:26 AM
Here's a quick crappy demo, dry as a bone.. too much gain :-\

http://dl.dropbox.com/u/11178619/BlackForest2.mp3
What was the recording chain? I always make that as simple, as I can - guitar>effect>line input in the PC>some guitar cab impulses on reaper, using LePou LeCab plugin.
When I put your sample through some impulses it sounded better, you know. ;p

No kidding, that sounds BEAST with the cab sims. I WILL be building this.

Any chance of someone posting a sample with the cab sims on it?  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 04, 2012, 11:39:35 AM
Here's a quick crappy demo, dry as a bone.. too much gain :-\

http://dl.dropbox.com/u/11178619/BlackForest2.mp3
What was the recording chain? I always make that as simple, as I can - guitar>effect>line input in the PC>some guitar cab impulses on reaper, using LePou LeCab plugin.
When I put your sample through some impulses it sounded better, you know. ;p

Really cheap Jay Turser 7 string, I payed $150.00 for it brand new and it has some let's say less than good pickups in it... -> DIY TS808 tubescreamer with the level on about 3 or 4. tone in the middle/12noon and the drive all the way off -> Black Forest -> Line 6 GX USB recording device -> Reaper -> LeCab with some shitty impulse... that's it. If you have any impulses you would like for me to use then send them to me and I will use them  :icon_biggrin: Plus, I need some good impulses... All I have is some crappy ones I downloaded from guitarampmodeling.com about 2 years ago.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 04, 2012, 11:57:55 AM

Why the jumper between R18 and C22 ?

Dan

There was a 470k resistor there but I removed it and replace it with a jumper to increase the output volume... I guess I could go back into the layout and extend the trace, maybe later after I get final Rev of this board. In the schematic there is a final buffer stage after the tone stack that I left off. I may add that back in and see how it sounds? I left it off to save on parts like another J201 etc and to keep it smaller board wise. I really wish I could make a board with the boost circuit, full Uberschall layout and on-board pots and maybe a speaker emulator! But, that is a friggin task and I am dyslexic which makes on-board pots a nightmare! Everytime I try to make on-board pots I get one or two of them reversed and that right there PISSES ME OFF!!! :icon_twisted:

@ bancika - Thanks man! DIYLC is a great program! Is there any way to create a ground plain in it? I use it to draw out the boards and layout the part diagrams but then I have to recreate the board in Sprint so I can add GP... Sprint sucks for part diagrams but kills on the boards.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 04, 2012, 12:45:27 PM
Some impulese: http://relivethefuture.com/music/patches/GuitarHacksImpulses.rar
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: meffcio on September 04, 2012, 12:47:55 PM
If you have any impulses you would like for me to use then send them to me and I will use them  :icon_biggrin: Plus, I need some good impulses... All I have is some crappy ones I downloaded from guitarampmodeling.com about 2 years ago.
Dude, I'm shocked :D
http://signalsaudio.com/Products/Gods_Cab_1.4.zip

that's one of the nicest layouts I've seen drawn in my diylc :proud: :)
Lol. And I was wondering what soft did he use. I am shocked again.

@ bancika - Thanks man! DIYLC is a great program! Is there any way to create a ground plain in it?
I can tell you how I've done ground planes in DIYLC. Tracks. Whole lotta tracks. :D
(http://s16.postimage.org/6mr13eijp/Bez_tytu_u.gif)

Some impulese: http://relivethefuture.com/music/patches/GuitarHacksImpulses.rar
Yeah, some of them are also ok. The point is to use more than one at a time. ;)

Any chance of someone posting a sample with the cab sims on it?  ;D
Well, I'm not a producer, so it's still bad, but you get the idea.
http://www38.zippyshare.com/v/60407449/file.html
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: artifus on September 04, 2012, 02:15:14 PM
@ bancika - Thanks man! DIYLC is a great program! Is there any way to create a ground plain in it? I use it to draw out the boards and layout the part diagrams but then I have to recreate the board in Sprint so I can add GP... Sprint sucks for part diagrams but kills on the boards.

diylc 3.13 and up offer ground planes.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 04, 2012, 02:49:22 PM
@meffcio  That sounds great man, impulses really bring out the punch.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: nightendday on September 04, 2012, 02:54:12 PM
Here's a quick crappy demo, dry as a bone.. too much gain :-\

http://dl.dropbox.com/u/11178619/BlackForest2.mp3
What was the recording chain? I always make that as simple, as I can - guitar>effect>line input in the PC>some guitar cab impulses on reaper, using LePou LeCab plugin.
When I put your sample through some impulses it sounded better, you know. ;p

No kidding, that sounds BEAST with the cab sims. I WILL be building this.

Any chance of someone posting a sample with the cab sims on it?  ;D


(http://tindeck.com/image/jtjm/stats.png) (http://tindeck.com/listen/jtjm)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 04, 2012, 03:22:53 PM
That sounds pretty monstrous!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: semicolonoscopy on September 04, 2012, 03:33:51 PM
Oh, I've gotta build this. I have the AMT clone of the Bogner Ecstasy, but this sounds even more aggressive.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 04, 2012, 03:37:55 PM
Nah, I use diylc to make the initial board and layout and then I flip over to Sprint and re-create the board...  :icon_confused: I will have to check into the diylc GP thing.. maybe I am missing it, maybe using older version?

(http://dl.dropbox.com/u/11178619/Copy%20of%20BF%20Board.png)

@ meffcio and pakrat - Thanks for all those impulse links! Now I am gonna get lost sorting through all of them :icon_rolleyes:

Here she is... naked :icon_redface:
(http://dl.dropbox.com/u/11178619/close.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: artifus on September 04, 2012, 03:44:51 PM
check your light bulb - bottom right - in diylc for updates. gp is under connectivity - the big black block.

bunch of ampsim stuff here: http://www.guitarampmodeling.com (http://www.guitarampmodeling.com) - mostly freeware.

*edit* nice board!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 04, 2012, 04:57:01 PM
Nah, I use diylc to make the initial board and layout and then I flip over to Sprint and re-create the board...  :icon_confused: I will have to check into the diylc GP thing.. maybe I am missing it, maybe using older version?

(http://dl.dropbox.com/u/11178619/Copy%20of%20BF%20Board.png)

@ meffcio and pakrat - Thanks for all those impulse links! Now I am gonna get lost sorting through all of them :icon_rolleyes:

Here she is... naked :icon_redface:
(http://dl.dropbox.com/u/11178619/close.jpg)

Drool......
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 05, 2012, 09:34:43 PM
I don't know if I posted this already but R16 should be 10k not 100k... The boost switch doesn't do a whole lot to justify a switch, may just want to remove R11 and replace with a jumper... Thinking changing R15 or adding a switch to say 560 or 680 range maybe lower may give some added gain/boost? Will try that tonight..

EDIT: Ok, I changed R15 to 680 and WHOA!!! This thing is smokin bad@ss now folks!!!

10k on R16 is a must... All the knobs function really well now!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on September 07, 2012, 06:27:05 AM
Just listened to the mp3 clips - I will have to build this - great work Jok3rx.

If anyone in the UK plans to get some PCBs done, I will happily buy one.  Otherwise it's vero for me...  :icon_cry:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on September 12, 2012, 03:23:47 PM
.............. this kills the thread.


Anyways - off the back of this topic, I just ordered some press-n-peel, copper board and ferric chloride.

Wish me luck !!!  :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 12, 2012, 05:28:52 PM
Good luck scuzzphut, we have faith you will be successful!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 12, 2012, 06:41:36 PM
Just listened to the mp3 clips - I will have to build this - great work Jok3rx.

If anyone in the UK plans to get some PCBs done, I will happily buy one.  Otherwise it's vero for me...  :icon_cry:

Not so fast... I have some updates! I will post them in a little bit.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 12, 2012, 08:16:28 PM
Here ya go... This one KILLS!!!!!!  :icon_twisted:

(http://dl.dropbox.com/u/11178619/BF_ULTRA_R3_Small.png)

Larger pic, easier to see  :icon_eek:
http://dl.dropbox.com/u/11178619/BF_ULTRA_R3.png

Board Transfer
http://dl.dropbox.com/u/11178619/BF-ULTRA.pdf
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 13, 2012, 01:10:38 AM
Thank you J0K3RX! I'll order parts tomorrow  :icon_biggrin:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on September 13, 2012, 02:13:31 PM
 :o That was close - press n peel arrived today !

Thanks Jok3rx
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 13, 2012, 08:22:55 PM
:o That was close - press n peel arrived today !

Thanks Jok3rx

Yer welcome! I hope you and pakrat like it...? I gotta try that press n peel one day!

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 13, 2012, 09:19:16 PM
Easiest pcb etching ever.... print on glossy magazine paper and 3 passes through a laminator. No expensive pnp blue, takes 1 min and it comes out perfect! I do use pnp for etching enclosures though....
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 13, 2012, 10:36:16 PM
Easiest pcb etching ever.... print on glossy magazine paper and 3 passes through a laminator. No expensive pnp blue, takes 1 min and it comes out perfect! I do use pnp for etching enclosures though....

I am not much for etching enclosures myself... maybe for 1 for myself but if I had to do 5 or 10 that would be a huge pain in the @ss for me! I need to look into a laminator though, the clothes iron is a bit of a pain. I have 500 sheets of some kind of glossy paper that works real good, almost just dissolves when I run some cold water over it after I have ironed it on the copper. I do need to figure out some easy method of painting the enclosures or something? I did a print on photo paper and then ironed it on an enclosure and just left it on there like that, then I clear coated over it and it looked awesome! May try that again..
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 13, 2012, 11:11:57 PM
I am about to try waterslide decals for the first time, I'll let you know how it turns out. I hate etching enclosures because it's a TON of work, but I love the outcome so I do it. Me and a buddy of mine are working on a foolproof way to transfer without an iron. The laminator for pcbs IS like cheating, you won't regret trying one. It comes out flawless every time, and is so little work to transfer. I use a 20 year old version of this one: https://www.laminator.com/model-5000-id-card-pouch-laminator-3-7-16-inch.html  Now, if I could only automate the drilling.......
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 13, 2012, 11:31:13 PM
I am about to try waterslide decals for the first time, I'll let you know how it turns out. I hate etching enclosures because it's a TON of work, but I love the outcome so I do it. Me and a buddy of mine are working on a foolproof way to transfer without an iron. The laminator for pcbs IS like cheating, you won't regret trying one. It comes out flawless every time, and is so little work to transfer. I use a 20 year old version of this one: https://www.laminator.com/model-5000-id-card-pouch-laminator-3-7-16-inch.html  Now, if I could only automate the drilling.......

That's a heavy duty looking laminator! I may look into getting one soon. I have wondered about the water slide decals myself? Let me know how you make out with that, looks like it will work pretty nicely... Another reason I don't like etching enclosures is that I use up a lot of ferric chloride and I seem to have a hard time getting that stuff. The worst part of the whole deal to me is drilling the boards! I am going SMD as soon as possible but I stll have a crap load of through hole parts so probably won't be too soon. I have a partially used reel of SMT J201's over 1000, and am about ready to get a large variety of 1206 SMT resistors for dirt cheap... smaller boards, no lead clipping, and best of all NO DRILLING, except for stuff like caps, wires etc..  
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 14, 2012, 01:01:55 AM
It will be a while for me to get into SMD, but I definitely plan on it in the future. By the way, a few questions on this layout.... 1) How are the pots wired for this? I get which pot goes where, but how are the pads numbered to the pot lugs? 2) This pcb looks huge, will it even fit into a 1590bb enclosure?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 14, 2012, 02:59:46 AM
It will be a while for me to get into SMD, but I definitely plan on it in the future. By the way, a few questions on this layout.... 1) How are the pots wired for this? I get which pot goes where, but how are the pads numbered to the pot lugs? 2) This pcb looks huge, will it even fit into a 1590bb enclosure?

The pots should be 1-2-3 where 1 is the square pads.

Did you print from the pdf? The pdf will print to scale... If anything I think it's a bit too small from the pdf but hey, that's what diylc spit out... If you print from the pdf you should be able to get 3 of them into a 1590bb enclosure :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on September 14, 2012, 03:04:51 AM
looking good jim...

you must have 500 hi gain monsters by now..  \m/ :icon_twisted: \m/
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 14, 2012, 06:52:00 AM
looking good jim...

you must have 500 hi gain monsters by now..  \m/ :icon_twisted: \m/

Thanks Rob.. Only a few ever find a home in a enclosure, this is one of them! Best one I have made yet! Still working on the Soldano Avenger, it may be another... New ENGL Invader coming soon :icon_evil:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on September 14, 2012, 09:27:30 AM
Quote
I am about to try waterslide decals for the first time,

I've been using decals for a while now and have learned the following :

(1) Cut out your printed decal bigger than required , then clearcoat and let dry.
(2) Once dried - cut to correct size.   

The clearcoat prevents the decal from breaking up and the second cut-to-size stops it from sticking to the backing paper.

Finally - spray lacquer for the final coat gives a really nice finish.   ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 14, 2012, 11:24:30 AM
Thanks scuzzphut, I already have the whole sheet clear coated. I will probably apply it tonight and then several coats of clear on top. All paper isn't created equal either, I bought some on ebay that just turned to goo when wet. The new paper I'm using is papilio, and the graphic printed very crisp. We shall see how it applies later.....
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on September 14, 2012, 12:28:31 PM
Couple of questions  : 

(1) I assume this is designed to go straight into the power amp section, rather than into the regular guitar jack ?  I've built a Dr Boogey and a Soldano S1 (AMT Legend) and they both improve when I bypass the preamp on my Blackstar HT-5.

(2) The pots are numbered 1 to 3 with the square being 1. Is this looking from the bottom with the lugs to the north ?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 14, 2012, 04:18:39 PM
@scuzzphut 1) I believe he did intend for this to go into the power amp section or return jack. 2) If the square pad is #1, then yes.... the next one up is #2, then #3. By the way, sprayed 3 coats of clear on the decal last night and today and the color came off when I put it in water  :icon_sad: I just did a new one with now 6 coats.... back to waiting overnight for it to dry. I hope this works or I'm etching again.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on September 14, 2012, 04:24:21 PM
Hi pakrat.

That's really weird about your decal. I usually print (inkjet) allow to dry overnight, one coat of clear ( I have used Plastikote fast dry enamel and Citadel Purity Seal from the local Warhammer shop) which I then allow to dry for a few hours and then cut and apply. I only put the decal in warm water for about 20 seconds. Hope this helps in some way.

As for the pots - I was asking about how the lugs on the actual potentiometer are numbered. My method so far has been to guess, then when it turns out it's the wrong way round, I fix it.  >:(  There has to be better science than this !!

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 14, 2012, 05:03:18 PM
Here ya go http://www.beavisaudio.com/techpages/Pots/
Thanks for the input on my decals... I have read some posts on it and have seen people using krylon acrylic clear, which is what I used. If this one doesn't work, I'll try lacquer.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 14, 2012, 06:57:57 PM
Think of it this way.. if you are looking at the board from the component side try to picture it like the schematic...

This picture should help...? You can play connect the dots or in this case connect the pots :icon_mrgreen:

Hint: My boards are almost laid out just like the schematic and, I did the first one for you :icon_wink: You may ask why? Cause I suck at creating boards :icon_lol:

(http://dl.dropbox.com/u/11178619/TS%20Layout.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 14, 2012, 07:35:06 PM
Couple of questions  :  

(1) I assume this is designed to go straight into the power amp section, rather than into the regular guitar jack ?  I've built a Dr Boogey and a Soldano S1 (AMT Legend) and they both improve when I bypass the preamp on my Blackstar HT-5.

(2) The pots are numbered 1 to 3 with the square being 1. Is this looking from the bottom with the lugs to the north ?

You built the AMT S1? Must share...? Do you have any clips of it? I built it a couple times from the schematics in "another forum" and it sounded like sh!t... I figured if I really wanted a SLO100 I would just find the actual schematic and do it myself.

About how to run this thing... try whatever you want, it's not like it's gonna explode :icon_eek: :icon_mrgreen: Since it's a "preamp" it would probably be best to either run it into a power amp or direct for recording but I would not exclude trying to run it into the front of an amp... They do it with the Dr.Boogie and it's a preamp just the same and I have heard good results...

pakrat: You said your board looks huge? How big is it, any pics? Should be quite small...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on September 15, 2012, 06:04:15 AM
The photos of my AMT S1 build are here -------->  http://imgur.com/a/qw342 (http://imgur.com/a/qw342)

YOU ARE NOT ALLOWED TO LAUGH AT THE GUT SHOT !!!

I had this thing apart and back together so many times that couldn't be bothered tidying up when I finally got it working.  :icon_redface:

There's a couple of single header sockets you can see at the top right. I was experimenting with different caps, then decided that I preferred no cap. Just in case anyone's wondering. Build from |V|ark's vero here -----> http://tagboardeffects.blogspot.co.uk/2012/04/amt-s1-legend.html


Here's a wee mp3 clip of it.  Guitar -> AMT S1 Clone -> Holy Grail Reverb -> FX Return on Blackstar HT-5 -> SM58 about 1" away from the grille

https://dl.dropbox.com/u/557078/amts1.mp3 (https://dl.dropbox.com/u/557078/amts1.mp3)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 15, 2012, 07:29:41 AM
The photos of my AMT S1 build are here -------->  http://imgur.com/a/qw342

YOU ARE NOT ALLOWED TO LAUGH AT THE GUT SHOT !!!

I had this thing apart and back together so many times that couldn't be bothered tidying up when I finally got it working.  :icon_redface:

There's a couple of single header sockets you can see at the top right. I was experimenting with different caps, then decided that I preferred no cap. Just in case anyone's wondering. Build from |V|ark's vero here -----> http://tagboardeffects.blogspot.co.uk/2012/04/amt-s1-legend.html


Here's a wee mp3 clip of it.  Guitar -> AMT S1 Clone -> Holy Grail Reverb -> FX Return on Blackstar HT-5 -> SM58 about 1" away from the grille

https://dl.dropbox.com/u/557078/amts1.mp3 (https://dl.dropbox.com/u/557078/amts1.mp3)

WoW! I see you told |V|ark... Wonder why he still has it on hold? Anyway, you got it working so who gives a sh!t what it looks like under the hood! I have NEVER made a good looking vero...EVER! Mine always end up looking like something the cat puked up after I'm finished :icon_mrgreen: I really don't like vero, it's confusing for me... ??? And, I absolutely can't make my own layouts on vero! The whole concept is nice, no drilling and all but I always get some goofy looking and funky working sh!t in the end! Anyway, nice paint and it sounds pretty good!  :icon_biggrin:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 15, 2012, 11:59:07 AM
The photos of my AMT S1 build are here -------->  http://imgur.com/a/qw342


Very clean, nice looking box scuzzphut!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 15, 2012, 12:35:33 PM
scuzzphut: I can't wait to hear what the Uberschall sounds like through the FX return of your Blackstar HT-5! :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on September 15, 2012, 02:22:57 PM
......going to have to learn some Slayer riffs !
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 15, 2012, 04:17:34 PM
Slayer  :icon_twisted:

Update: You know how I was complaining about the tone stack and the bass not really having any range, almost no difference from 2 all the way to 10... Well, I fixed that! I think now the tone stack is VERY good! Good news, no board changes :icon_biggrin:

Changes - New values:
R21 - 33k
R17 - 22k
Treble - B100K
Mids - B10K

Optional:
If you want to leave out the Presence control/pot just replace R18 with a 33k resistor and C21 with a 10nF cap, then stick a jumper in the holes for the Presence pot lugs 1 and 2
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 15, 2012, 04:57:01 PM
Good news, no board changes :icon_biggrin:

Well that's a relief, I already etched the board....
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 15, 2012, 05:09:46 PM
Good news, no board changes :icon_biggrin:

Well that's a relief, I already etched the board....

You should see mine now! I'm still using the first board, all kinds of mods and crap hanging off of it... Looks like a transistor orgy!  :icon_lol:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 15, 2012, 07:16:08 PM
That's how my boards usually end up after debugging. A shame too, they look so nice when they're new.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 16, 2012, 11:47:18 PM
OK, I think I have perfected this! I tested it direct and also through a MosValve power amp into a 4x12 cab. All I gotta say is "WOWZERS!!!" To quote Cypress Hill, this thing is "INSANE IN THE MEMBRANE" ***WARNING*** THIS MAY CAUSE MELTING OF THE FACE! 

After a lot of messing around I added a gain boost which you can either make foot switchable or toggle switchable or leave it off, your choice.. I strongly recommend that you add it because it is quite a noticeable boost in gain and it really sounds good!! Not muddy at all, nice and tight, more sustain and gain of course! Great for switching between rhythm and lead! You may want to experiment with the two resistor values to get the gains you like, these are just the values I liked with my guitar which has average output stock pickups. If you have EMG's or other high output pickups you may want to adjust these resistors accordingly..!? I have also made changes to the tone stack which is now fully functional, required no board layout changes, just different part values... :icon_wink:

In the beginning I was considering adding some sort of tube screamer circuit to this but now you definitely "DO NOT" need a tube screamer!!! This has more tight massive gain than you will probably ever need! My MosValve was screaming for vengeance with this little beast running into it!!! Sounded like a $3000 custom high gain amp! Not kidding! And, running direct it just kills! Not sure if it sounds like a real Uberschall but I don't think I changed enough parts to affect the over all tone from the original schematic.. Anywho, this thing just flat out kix @ss and sounds mean as hell!!! :icon_twisted:

REV 3.1
(http://dl.dropbox.com/u/11178619/BF-REV3.png)

Here is the off-board wiring minus the pots.. let me know if you see anything I can do differently/improve...?
(http://dl.dropbox.com/u/11178619/BF-REV3-Wiring.png)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 16, 2012, 11:57:01 PM
Jut FYI - Shielded wiring is highly recommended! :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on September 17, 2012, 04:42:19 AM
indeed... :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on September 17, 2012, 08:57:19 AM
JOK3RX - can you give us the latest version without the blue background please ?  My printer hates me !
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on September 17, 2012, 09:15:55 AM
I just pm'd you a pic of it.  i just used the color fill tool on ms paint ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on September 17, 2012, 09:29:19 AM
thanks hysh  :)  should have thought of that myself, on reflection....
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 17, 2012, 10:32:56 AM
Thanks for all of the work you have put into this J0K3RX! Ordering parts now.....
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: 23 on September 17, 2012, 09:36:25 PM
Man I wish I was still building pedals, read this whole thread and I rarely do that. Wicked job.

Sands
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 18, 2012, 12:52:50 AM
Man I wish I was still building pedals, read this whole thread and I rarely do that. Wicked job.

Sands

Consider this as your way back in man, another set of ears couldn't hurt! And yes, wicked job indeed...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on September 18, 2012, 05:51:12 PM
J0K3RX - I'm looking at the LEDs and wondering if the single LED off the 3PDT is redundant because of the dual colour one.

I'm thinking that I switch the 9V through the 3PDT to R23.

Unless - were you thinking that the 2 colour would always show the mode, regardless of whether the pedal is engaged or not ?  So that you can see what mode it's in before you stomp into boost mode and drown out the drum solo ?? (might not be a bad thing.....)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 18, 2012, 06:39:01 PM
J0K3RX - I'm looking at the LEDs and wondering if the single LED off the 3PDT is redundant because of the dual colour one.

I'm thinking that I switch the 9V through the 3PDT to R23.

Unless - were you thinking that the 2 colour would always show the mode, regardless of whether the pedal is engaged or not ?  So that you can see what mode it's in before you stomp into boost mode and drown out the drum solo ?? (might not be a bad thing.....)

Yeah, there are a few options you can do... I just did it this way because of simplicity. The 3PDT tells you if the pedal is engaged or in bypass mode and the boost switch which is independent lets you know if you are in high gain mode or lower gain mode. The gain/boost switch is really just a gain boost, it does not increase the volume... You can try whatever configuration you like :icon_wink: Share here what you come up with?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 18, 2012, 06:50:26 PM

Unless - were you thinking that the 2 colour would always show the mode, regardless of whether the pedal is engaged or not ?  So that you can see what mode it's in before you stomp into boost mode and drown out the drum solo ?? (might not be a bad thing.....)

Definitely a good idea but..... if you are using this as a preamp as I am planning to, then it would always be on anyway. The dual led will always let you know what mode you're in.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 18, 2012, 07:23:30 PM

Unless - were you thinking that the 2 colour would always show the mode, regardless of whether the pedal is engaged or not ?  So that you can see what mode it's in before you stomp into boost mode and drown out the drum solo ?? (might not be a bad thing.....)

Definitely a good idea but..... if you are using this as a preamp as I am planning to, then it would always be on anyway. The dual led will always let you know what mode you're in.

I was going to make a 3 channel, Lead - Rhythm - Clean :icon_mrgreen: Might want a bigger enclosure though! Good news is you can just use 2 stages bypassing the rest for the clean channel... Bad news is you will probably want to add some extra pots :icon_frown: but, would be cool huh!? maybe later :-\
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 19, 2012, 02:35:47 PM
A 3 channel would be sick! I just happen to have a 1790s that would be perfect for that  :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 19, 2012, 03:16:31 PM
A 3 channel would be sick! I just happen to have a 1790s that would be perfect for that  :icon_wink:

Let me draw it up for ya :icon_mrgreen: I'm not gonna test it cause I am busy doing some other stuff so you will be the pioneer on this one... I am sure it will work. Plus I don't have a bunch of extra pots to spare right now...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 19, 2012, 04:33:16 PM
Sweet.... I'll build it both ways and do some testing before boxing it up. I might have to build 2 of these now  :icon_evil:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 22, 2012, 11:05:33 AM
Here is a less metal sound I recorded real fast before I stick it in a box... still pretty heavy but toned down a bit. Sh!tty playing, timing horrible but if I run a Superior Drummer it kills my CPU... It's already killing my CPU just running a cab sim and slight delay! :icon_frown: Computer SUCKS!!!

http://dl.dropbox.com/u/11178619/Dragon%20Attack2.mp3

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 22, 2012, 11:19:03 AM
Sounded great to me man. Toned down? It still sounds heavy as hell with a rich bottom end. I can't wait for my parts to show up and have this project kick all my others off the bench! And your playing was great too.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 22, 2012, 11:37:00 AM
Sounded great to me man. Toned down? It still sounds heavy as hell with a rich bottom end. I can't wait for my parts to show up and have this project kick all my others off the bench! And your playing was great too.

Ha ha.. Thanks man!

Here's my box.. what a pain in the @ss! Oh and I re-named it as you can see... :icon_rolleyes:

(http://dl.dropbox.com/u/11178619/Paint%20-%201.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 22, 2012, 11:48:36 AM
That looks great, nice and dark  :icon_evil: Is that decals on that?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 22, 2012, 12:22:58 PM
I just did my first waterslide on a tubescreamer, and I thought I'd never say this, but etching is much easier for me! I did manage to get a great buffed surface, but the decal curled when I installed the nuts for switches etc... Now I know for next time to cut the holes in the decal BEFORE the clear. All in all it came out nice, and now I'm under the gun to finish boxing it before a gig tonight.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 22, 2012, 12:40:43 PM
I just did my first waterslide on a tubescreamer, and I thought I'd never say this, but etching is much easier for me! I did manage to get a great buffed surface, but the decal curled when I installed the nuts for switches etc... Now I know for next time to cut the holes in the decal BEFORE the clear. All in all it came out nice, and now I'm under the gun to finish boxing it before a gig tonight.

I need to get those water slide decals! Thanks for the tip about the holes!! I used photo paper and transferred the image on with toner and then clear coated over the toner. As soon as the clear coat goes over the toner it turns black. After it dried I turned it face down and painted the sides flat black. Then after that dried I turned it back face up and clear coated the whole thing again.. Works pretty good except I burned the F__K outa my finger tips while I was ironing the stupid toner image on the top!!! :icon_evil:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 22, 2012, 01:34:39 PM
Yeah, never enjoyed the ironing much.... I love results though, so I keep going. Of course I box this thing up and it doesn't work. I first had it hooked up to a beavis box, awesome for trying stuff out. Box it up... no go. I guess I don't get to use my shiny new tube screamer for the show  :icon_sad:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 22, 2012, 01:54:08 PM
Well duh, I had in and out from the board reversed. Funny how the stupid things can trip you up.....
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: vendettav on September 23, 2012, 03:11:46 AM
Nice tone actually, I'm quite loving it! haha
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Maik on September 24, 2012, 09:52:22 AM
I need to get those water slide decals!

Hey JOK3RX, check out decals for ceramic. You have to put them into an oven and the decal will burn in. You can drill the box after finishing and the decal will NOT come up.

http://www.pearl.de/a-VM5726-2421.shtml
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 24, 2012, 10:01:17 AM
I need to get those water slide decals!

Hey JOK3RX, check out decals for ceramic. You have to put them into an oven and the decal will burn in. You can drill the box after finishing and the decal will NOT come up.

http://www.pearl.de/a-VM5726-2421.shtml

Thanks Maik! I am gonna have to look for those on ebay! I live in the US :icon_rolleyes:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 25, 2012, 12:11:09 PM
@Maik Have you actually tried baking one of those onto an enclosure? I'd like to try that myself since I have learned I hate waterslides.....
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 25, 2012, 12:13:29 PM
And I decided to post this while I wait for the parts to arrive....

(http://i1072.photobucket.com/albums/w375/pakrat70/SEVENLEAF%20EFFECTS/BLACKFORESTETCH_zps537926d7.jpg)

Muhahahahaaaa........
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 25, 2012, 07:11:09 PM
pakrat that looks great!

Ok so you guys know this is a WIP right? WIP = Work In Progress...

Don't hate me but I have made a few changes :icon_redface: Nothing much on the layout except the position of R6, it's been moved between stages 3 and 4 instead of 2 and 3. The rest of the changes are part values. please examine carefully! The old setup will work 100% these are just what I believe to be improvements to the design. The pads for R6 can easily have a jumper installed then make a couple holes between the 3rd and 4th stage and cut the trace in between. Stick the resistor in the new holes and bend the leads over and solder them to the traces... Bingo :icon_wink: Again, some part values have changed! Busy right now or I would itemize them... maybe one of you guys could compare and make the list? :icon_biggrin: very small, maybe 4 or 5 very common parts...

Layout in white so it doesn't kill your printer :icon_mrgreen:
(http://dl.dropbox.com/u/11178619/BFUltra%20-%20R3.2.png)

board transfer.
http://dl.dropbox.com/u/11178619/BFUltra%20-%20R3.2.pdf
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 25, 2012, 07:27:59 PM
J0K3RX..... you b@stard lol!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 25, 2012, 07:56:47 PM
J0K3RX..... you b@stard lol!

Board came out great! You can mod it, I have faith in you! :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 25, 2012, 08:44:51 PM
Yeah it's no problem... I don't notice too many differences, just a few cap changes and the resistor swap? Also, any reason why c1 abd c22 are both 100uf electros but different voltages? This should run at 9-12v correct?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 25, 2012, 09:00:32 PM
Yeah it's no problem... I don't notice too many differences, just a few cap changes and the resistor swap? Also, any reason why c1 abd c22 are both 100uf electros but different voltages? This should run at 9-12v correct?

The voltages are just a goof on my part...  :icon_rolleyes: I try to keep them all 25v cause I am weird :icon_twisted:
C1 and C21 should be at least 12v minimum or 25v if you want to run at 18v... If you bias @9v and then run at 18v your biasing my be off @ 18v though? But that's just a guess... Actually you can use 220uF for C1, but I didn't really notice any difference between 100uF and 220uF. 

R6 is now 1k, I had it at 10k which is what the actual tube preamp had but the tube preamp runs @ 300v + so that was not in spec with 9v... It was dropping the voltage at the positive side of C1 to 6.7v which was starving the first two stages. I could bias the to 4.5v but that was not half of the supply voltage. Half would or should have been something like 3.4v which is all out of whack.. Sounded good somehow but just not quite right.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 25, 2012, 11:33:00 PM
Ok, that's fine.... I usually get 25v for the size anyway. I'm gonna build it according to the v3.2 layout exactly as you have it, and prob try 9, 12, and 18v just to see. I'll trim to half the working voltage. Thanks again for the work you're putting into this!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on September 26, 2012, 06:00:38 PM
I turn my back for five minutes and everything's changed again  :icon_evil:

Just kidding  - not had much time lately - concentrating on finishing my lightwah when I get a spare hour.

Are you happy with this now J0k3rx or are you still tinkering ?? I've etched my PCB (the version before the mod, but I'm sure that won't be much of a hardship) and will probably be starting to populate it at the weekend.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 26, 2012, 08:07:16 PM
@scuzzphut Even if he says he's finished.... don't believe him  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 26, 2012, 08:34:41 PM
I turn my back for five minutes and everything's changed again  :icon_evil:

Just kidding  - not had much time lately - concentrating on finishing my lightwah when I get a spare hour.

Are you happy with this now J0k3rx or are you still tinkering ?? I've etched my PCB (the version before the mod, but I'm sure that won't be much of a hardship) and will probably be starting to populate it at the weekend.


I think the main backbone of this pedal is done... The rest is just bells and whistles that can be added to the last layout either by changing a few parts or making a small perf board or whatever... There are so many little things that you can do to these pedals and I just want to find the best of the best and to hell with the rest! Some mods like the "Wide" switch can be left off and just keep it set to wide all the time since I think that sounds best anyway. I just want to have 2 toggle switches, 2 foot switches (High and Low Gain) and 6 knobs. One could even leave off the presence knob since I have it all the way up most of the time or you could just make a presence switch. You start going crazy with switches and mods and then you end up with something that doesn't even sound like what you had in the beginning... Then you end up trashing it all and going back to the start :icon_rolleyes: Keep it pure and simple and keep the features that you really want.

That being said; In the future I will probably make the tone stack separate from the main board for a couple of reasons. Number 1) Most if not all of these preamps use the same tone stack and if I had a tone stack board I could just use the same TS board for each preamp. Number 2) There would be much less wiring going to the pots since they would be attached directly to the board, less of a mess, looks better, less work and maybe less noise etc. Number 3) I could layout the boards quicker since I wouldn't have to lay out the tone stack every time and the main board would be shorter and easier to work with not having the extra caps, resistors and holes.

This is kinda what I was thinking... The traces and holes for the resistors and caps have not been added yet but you can get the idea from the pic.
(http://dl.dropbox.com/u/11178619/Ts%20board.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 26, 2012, 08:44:30 PM
@scuzzphut Even if he says he's finished.... don't believe him  ;D

pakrat & scuzzphut are like the two old men in the balcony on The Muppet Show that heckle the performers in the theater.... :icon_biggrin:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 27, 2012, 12:45:19 AM
I guess I'm Waldorf.......
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on September 27, 2012, 12:56:21 AM
@ jim

Do you happen to know what setup Dimebag had on 'Walk'?  Some say it was a tweaked Randall but others say Krank. If you could emulate that sound you would be a god in my eyes :D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 27, 2012, 03:14:25 AM
@ jim

Do you happen to know what setup Dimebag had on 'Walk'?  Some say it was a tweaked Randall but others say Krank. If you could emulate that sound you would be a god in my eyes :D

Funny you should say that... I just so happen to have a project for that amp or what many believe that amp was...RG100ES solid state? hard to dupe!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on September 27, 2012, 03:47:55 AM
Yea, thats the one.  :icon_surprised: :icon_surprised: :icon_surprised: by amp project do you mean emulator pedal or the actual amp?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 27, 2012, 08:33:31 AM
Yea, thats the one.  :icon_surprised: :icon_surprised: :icon_surprised: by amp project do you mean emulator pedal or the actual amp?

preamp... but it is way at the back of my list of too doo's so don't hold your breath :icon_redface: Maybe a Krank sooner! I think a lot of the Dime sound was just his style... That dude was insanely good!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 27, 2012, 10:04:17 AM
Dime used Rg100ht, Rg100es, and the Randall century 200. Plus he had a furman pq3 or pq4 in his loop and an mxr graphic in his chain. I believe he scooped mids all the way out with the graphic and then added them back in with the pq. I actually play through that same setup basically and I can tell you, it sounds brutal! I have a layout of the randall RG100es from JMK but it's unverified.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 27, 2012, 10:17:03 AM
Shouldn't it be easy to copy the Rg preamp? It's a solid state amp, so it should just be an exact copy? I think the pre in the head runs at 24v though, so 9v would lose a lot of headroom? I bought a 24v power adapter for that project but the black forest has actually taken over my plans here...... Oh, and you are right J0K3RX, a lot of his tone was from his fingers and his absolute genius! RIP Dime!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 30, 2012, 01:26:45 PM
Ok, it's time for another update to piss off all of you that etched the last board :icon_mrgreen:

Here is a sound sample with and without the noise gate addon. Yes, I said noise gate! :icon_twisted:

Here are 4 takes and all were recorded without pause so you can hear the difference while I am switching and stopping between takes... Also, I didn't touch my vol on my guitar at all, it was on full for the entire sample so you can hear the noise or lack of noise when I stop playing...

They go in this order:
1) Boost off and noise gate on
2) Boost on and noise gate on
3) Boost on and noise gate off
4) Boost off and noise gate off
http://dl.dropbox.com/u/11178619/Noise%20Gate/Dragon%20Attack%20Noise%20Gate.mp3

If you like this then shoot me a PM and I will send it to ya... It's so simple you will laugh! :icon_lol:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on September 30, 2012, 01:38:52 PM
noise gate?.... now i'm curious.. :icon_eek:

simplest is always the best.... ;)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 30, 2012, 01:46:40 PM
noise gate?.... now i'm curious.. :icon_eek:

simplest is always the best.... ;)

Oh ok, twist my arm :P

(http://dl.dropbox.com/u/11178619/Noise%20Gate/NG1.png)

I wish this forum would host pics!  :icon_evil:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on September 30, 2012, 01:53:00 PM


if it works , do it...!..very cool. :icon_cool:  ....now make it adjustable? :icon_twisted:


me too on the hosting btw.. :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 30, 2012, 02:21:55 PM


if it works , do it...!..very cool. :icon_cool:  ....now make it adjustable? :icon_twisted:


me too on the hosting btw.. :)

I thought about making it adjustable but it works real good in both boost and normal modes, doesn't clip off the notes or decay, even if I roll my vol on my guitar back so...
I put a 500k pot in place of the 330k resistor and it works but if you switch off the gate it's still affecting that resistor which makes it sound like doodoo in normal mode.. I suppose I could get all crazy and make it switch back to a fixed resistor 470k or 220k but I really don't want anymore knobs.. maybe a high/med/low gate? Confusing ??? It work great I think so, unless somebody else wants to take it to the next level I am gonna just sit on it for now :icon_mrgreen:

I think the best way to make it adjustable is to replace the 1 meg resistor with a 1 meg pot! That would eliminate any problems when the gate is off since that is bypassed...This is a Peavey JSX noise gate btw :icon_wink: And, I have to credit Mensur for bringing it to my attention! :icon_wink:

See for yourself :o
http://elektrotanya.com/PREVIEWS/63463243/23432455/peavey/peavey_jsx20_guit.pdf_1.png
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on September 30, 2012, 03:33:28 PM

 :icon_eek: arghhhhhhhh

it sounds ideal for high gain chunky riffy stuff...nice one....and best of all simple too, ultra cool :icon_cool: :icon_cool: :icon_cool:

and yeah nice idea on the subtle/medium/blunt switching...

re: pot numbers/switches?...arghhhhhhhhhhhhhhhhhhhhhh i know, so/too many options, but worth it definately for hi gain chunky riffs.....on/off etc..optional. :icon_cool:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on September 30, 2012, 04:16:06 PM
I've got my board filled, can't fire it up until later though  :'(
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on September 30, 2012, 04:27:57 PM
Hi! thanks j0k3rx for sharing this!Really like it. Since I have some spare j201 I 'm working on a squeezed pcb layout, 1590B size. As a small contribution to this topic and awesome forum i think I'll share if you don't mind  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 30, 2012, 04:47:49 PM
Hi! thanks j0k3rx for sharing this!Really like it. Since I have some spare j201 I 'm working on a squeezed pcb layout, 1590B size. As a small contribution to this topic and awesome forum i think I'll share if you don't mind  ;D

Please do!  :icon_biggrin: Make it 3 or 4 knobs if you can!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on October 01, 2012, 05:07:44 PM
Actually I'm working on the full 6-knobs version like this drBoogie I made loooong time ago... :o
http://www.diystompboxes.com/smfforum/index.php?topic=86731.msg730006#msg730006 (http://www.diystompboxes.com/smfforum/index.php?topic=86731.msg730006#msg730006)
16 mm pots, vertical precision trimpots with boss style dc connector soldered to the board i think. Hopefully I'll order some presens boards next week to try the layout :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 01, 2012, 06:36:06 PM
Nice job on that Dr Boogie!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 01, 2012, 07:38:27 PM
Actually I'm working on the full 6-knobs version like this drBoogie I made loooong time ago... :o
http://www.diystompboxes.com/smfforum/index.php?topic=86731.msg730006#msg730006 (http://www.diystompboxes.com/smfforum/index.php?topic=86731.msg730006#msg730006)
16 mm pots, vertical precision trimpots with boss style dc connector soldered to the board i think. Hopefully I'll order some presens boards next week to try the layout :)

Riccardo,

Oh Damn!!!  :icon_eek: That is one of the best boogies I have seen yet!!! Make this pedal like that and I will be very happy!!! :icon_mrgreen:
Puts mine to shame! :icon_redface: Very clean job, looks very professional! :icon_wink:

Very excited to see what you come up with!!!!!!!!!!!

Damn Italians... :icon_cool: lol

Just kiddin... I'm half Italian so it's all rock & roll!

Edit: Man, the more I look at your Boogie the more of a boner I get!  :o  I like the pot wiring with the strain relief in the board!!! I have some Dr.Boogie mods I am gonna do soon and I am gonna use your board! I assume you won't mind since you posted it here?  :icon_wink:

Edit Again: Kinda reminds me of these but yours looks much better!!! And, just try to find those JFET/MOSFET's... never gonna happen!
http://www.nikitaeffects.com/jfet/jfet_series_en.html
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on October 02, 2012, 04:05:27 PM
Many thanks Jim  ;) You are free to use the layout and I want to see your drBoogie build! My suggestion is to use presensitized boards since the layout is very dense but I think it's suitable for PnP too. Thanks for the link..never seen before.

The black forest layout it's a bit different because i'm trying to reduce the amount of off-board wiring mounting the pots on the pcb. All in a single sided board ;)
I'll do the best to finish this in a reasonable time.. wish I could have more time for diy  :'(

In the meantime a little preview  ;D
(http://i875.photobucket.com/albums/ab315/Cap_87/Senzatitolo.png)

it's not complete yet, maybe there are errors..if you can send me a schematic I can double check the connections

Ciao! ;)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 02, 2012, 04:40:54 PM
Wow, that's nice Riccardo!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 03, 2012, 04:46:25 PM
Ok, I have a build report for this thing: At first I wasn't happy with the amount of gain I was getting, so JOK3RX advised me to experiment with R5 and R22 (normal and boost) and I'm glad I did! So far I'm at 68k for R5 and 100k (might be a little much) for R22 but I'm still experimenting. I haven't built the gate addon but I'm doing that right now. My advice to anyone who is into high gain pre's is to build this sucker, and experiment with R5 and R22 to get it to your liking. All in all a great sounding high gain pre that doesn't have that ugly fizzly high end.  I'll get some sort of sample together when I have time, but don't wait.... build this!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on October 03, 2012, 05:02:06 PM
Still unverified. Hope to verify the layout in the week-end

http://dl.dropbox.com/u/3511352/Black%20Forest%20Rev1%20test.pdf (http://dl.dropbox.com/u/3511352/Black%20Forest%20Rev1%20test.pdf)

this is so close to the final version, one jumper on the board and a couple of jumper wires to do under the board.
Once verified I'll provide all the info to wire this fx  ;)

..in a 1590B  ;D ;

EDIT: Thanks pakrat for the report, i use the same numeration of the components in my layout so it's easy to make mods
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 03, 2012, 05:22:15 PM
I love that layout! Well, I guess I'm building another......
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 03, 2012, 06:59:00 PM
Still unverified. Hope to verify the layout in the week-end

http://dl.dropbox.com/u/3511352/Black%20Forest%20Rev1%20test.pdf (http://dl.dropbox.com/u/3511352/Black%20Forest%20Rev1%20test.pdf)

this is so close to the final version, one jumper on the board and a couple of jumper wires to do under the board.
Once verified I'll provide all the info to wire this fx  ;)

..in a 1590B  ;D ;

EDIT: Thanks pakrat for the report, i use the same numeration of the components in my layout so it's easy to make mods


 :icon_mrgreen: :icon_mrgreen: :icon_mrgreen: This is a work of fine art!!! Some people just have a knack for this stuff and you my friend are a genius! And, all on single sided pcb too with on-board pots!!!  ;D To me laying out boards is like solving a rubix cube... and I sucked at rubix cube but, I gotta have me some HIGH GAIN so I make my lame layouts...

BTW - What if I make an ENGL using the same layout? That would make your 1590b layout even more bad@ss huh!!!  :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on October 04, 2012, 05:07:59 PM
Quote
BTW - What if I make an ENGL using the same layout? That would make your 1590b layout even more bad@ss huh!!! 
Posted on: Yesterday at 03:22:15 PM

Would be cool!

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 04, 2012, 08:26:15 PM
Still unverified. Hope to verify the layout in the week-end

http://dl.dropbox.com/u/3511352/Black%20Forest%20Rev1%20test.pdf (http://dl.dropbox.com/u/3511352/Black%20Forest%20Rev1%20test.pdf)

this is so close to the final version, one jumper on the board and a couple of jumper wires to do under the board.
Once verified I'll provide all the info to wire this fx  ;)

..in a 1590B  ;D ;

EDIT: Thanks pakrat for the report, i use the same numeration of the components in my layout so it's easy to make mods

Cap ~

I was thinking maybe you could add the pot for the noise gate where the presence is? You could still have the effect of the presence by running a 10nF and 56k to ground or something like that... just wouldn't be adjustable with a pot. I find that I have the presence all the way up almost all of the time anyway... Would be nice to keep the most usefull features since you are working with very limited space... Just a thought?

~ Jim
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on October 06, 2012, 06:04:14 PM
OK! The layout should be correct. Please report errors if you see any.

I used the same numeration of components as J0k3RX did.

http://dl.dropbox.com/u/3511352/Black%20Forest_1590B%20layout.pdf (http://dl.dropbox.com/u/3511352/Black%20Forest_1590B%20layout.pdf)


- pots need to be soldered by the copper side so you can easily bias the effect
- there is only one jumper (red) on components side and the other jumper wires are the yellow airwires

Not tried to etch yet. I need blank boards!! >:(

@ Jim: In the next days I'll try to modify the layout with the gate pot..I'll let you know if it's possible without going crazy ;D
Anyway it can be modded with the addon board or a piece of perf

Comments are welcome! and as a good italian I must write "sorry for my bad english"  :D

Ciao ;)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 06, 2012, 07:14:37 PM
Very nice Riccardo!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 07, 2012, 04:51:35 PM
Here's mine... probably won't work cause I am dyslexic :icon_rolleyes: I have so much trouble laying out tone stacks with on-board pots etc.. But this is what I am shooting for! BTW - The 5 light blue lines indicate where jumpers are to be installed. Also, a few wires need to be added to the switches...

(http://dl.dropbox.com/u/11178619/Noise%20Gate/BF_Rev6.JPG)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 08, 2012, 07:16:28 PM
Nice! It's like Xmas visiting this thread  :icon_biggrin:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on October 10, 2012, 01:10:00 PM
Like this?
http://www.diystompboxes.com/smfforum/index.php?topic=36392.msg751853#msg751853 (http://www.diystompboxes.com/smfforum/index.php?topic=36392.msg751853#msg751853)
 ;D ;D ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 27, 2012, 01:31:49 AM
This is the fix for the constant hum/noise problem for any of you who might have built it or were thinking of building...

Replace R15 and R16 both with 1.8k resistors. You can probably use 2.2k also but I used 1.8k so I know they work. Then remove R2 and replace with jumper and put a 470pF cap across R1. Replace C2 with a 220nF or 470nF cap. For the boost resistors (R22 and R5) I use 10k and 18k. If you replaced C22 with a 220uF cap you can leave that in there, it's fine... If you have 100uF that's fine, I don't notice any real difference between the two... Also, I removed the presence knob because it was causing weird problems with the tone stack mainly in the treble pot. Has plenty of presence anyway. The two main changes are R15 and R16 to 1.8k, all the rest is just fine tuned stuff...  Bias all of the transistors at half the voltage, mine are 4.3v for Q1, Q2 and Q3 then 4.5v for Q4 and Q5.  That's it, you shouldn't have any hum with the volume rolled all the way down on your guitar and just the expected noise you get with high gain when the volume is turned up.. And btw, I have the noise gate working perfectly which removes almost all of the "normal high gain noise" without killing the sound at all!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on October 27, 2012, 01:42:36 AM
I really want to make one but it keeps changing :icon_lol:

I etched a board early in this thread but it was kinda bad so I'm going to wait till the definitive layout.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 27, 2012, 01:54:05 AM
I built one Mike, and it's a monster. It seems the latest changes don't require a new pcb, so you might be safe now. Maybe socket the entire board?  ;D
Thanks for posting the improvements JOK3RX!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 27, 2012, 02:16:27 AM
High gain circuits are a real bitch!!! I am pretty much done with this now... ::) The low level hummmmm was a real problem, it was present even with the volume all the way off on the guitar or the pedal but the fix I posted will take care of that! After hours of sh!t trouble shooting I finally figured it out... The 4th jfet and the added gain stage were screaming with the audio probe and I couldn't figure out why... Turns out that both of the source resistors were way off causing the whole circuit to become a massive sh!t storm of hum and noise... Bumped those resistors up and bingo! So, I think you are safe now Mike ::) I am moving on to the ENGL and then I will finish the Soldano Avenger...

Pakrat - Let me know if this fixes yours?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 27, 2012, 02:19:19 AM
I'm glad you got it worked out Jim, I thought you might give up on this  :'(  I have to see if I have those caps laying around, I hope I do!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 27, 2012, 02:21:17 AM
I'm glad you got it worked out Jim, I thought you might give up on this  :'(  I have to see if I have those caps laying around, I hope I do!

The caps are not a big deal... the two resistors and a good re-bias will pretty much do the trick!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on October 27, 2012, 02:22:35 AM
Thanks Jim. I'm going to wait for pakrat's approval to start.

@pakat let me know if you don't have those caps ;)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 27, 2012, 02:24:36 AM
It's 2:30 am..... do I need to do this now??? I think so....... Gimme 10 min  :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 27, 2012, 02:37:45 AM
Testing.......
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 27, 2012, 02:46:57 AM
Ok, I replaced R15 and R16 with 1.8k, and removed R2 and it's dead quiet! Do I need to make the cap changes?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 27, 2012, 02:49:53 AM
Ok, I replaced R15 and R16 with 1.8k, and removed R2 and it's dead quiet! Do I need to make the cap changes?

dead quiet as in not working or dead quiet as in no more hummmm? You don't need to make the cap changes.. optional.  C2 tightens up the bottom end a bit... You need to re-bias...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 27, 2012, 02:53:40 AM
It is dead quiet, without the gate even. I can't remember which resistor I have for boost, but it's higher than 18k and it's still quiet! I still have a bit of an issue with a little static in the decay, but it might just be that I'm using a bugera 333xl to test. Tomorrow I'll try it in a better rig. Good job Jim, this thing really smokes!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 27, 2012, 02:56:18 AM
If you remove the noise gate and put it back to normal before the gate was added the static will probably go away.. I think your gate is whacky
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 27, 2012, 02:58:52 AM
I dunno what happened with the gate, but I'll try original boost value and see. At this point, the gate isn't needed and it is super high gain, go figure. Oh, one last thing.... to remove the presence pot, just take it out? I had tried removing the ground from the presence pot but it didn't make a difference with my tone pot.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 27, 2012, 03:00:28 AM
If you remove the noise gate and put it back to normal before the gate was added the static will probably go away.. I think your gate is whacky
My gate is removed already
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on October 27, 2012, 03:03:11 AM
Awesome. I will re etch and populate tomorrow!  I have to make a trip to the music shop to use their(better than my dumpsterjet) laserjet   :icon_lol:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 27, 2012, 03:06:15 AM
Maybe we should inform Riccardo of the changes here. He put a lot of work into his layout with the onboard pots. Now if we could only get him to add in the gate...... ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 27, 2012, 03:07:48 AM
Yeah Mike, I doubt you will be disappointed in this one. It sounds pretty sick with cab impulses on it too.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on October 27, 2012, 06:27:43 AM
@pakrat: did you tried my layout? damn.., I'm still waiting for my new copper boards to arrive :icon_evil:...hope to find time this week to add the gate ;) ...and try to etch myself my layout!!!! >:(
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 27, 2012, 10:54:24 AM
I didn't use your layout because I had already built this on the original pcb. I definitely plan to build one on your layout too, just to have it be more compact. If you have trouble etching the pcb, I'll make you one and send it to you  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 27, 2012, 05:20:57 PM
I tested mine today back to back against an AMT P1 pedal (since I don't have an Uberschall) through a TubeWorks MosValve power amp into a 4x12 cab with celestion v30's and also running direct using impulses with myself and two other guitar players and it was a unanimous decision that we all agreed the BF totally stomped the living sh!t outa the P1! All I have to say is WOW and good luck!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 27, 2012, 05:33:48 PM
With those resistor changes, my build sounds amazing as well. Are you going to update the layout with all of the value changes?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 27, 2012, 05:40:18 PM
With those resistor changes, my build sounds amazing as well. Are you going to update the layout with all of the value changes?

Yeah, I will do that maybe this weekend...

Now I am doing an ENGL version using the same board and I already have a working version of the ENGL which sounds jaw dropping!!!

Thanks for all your help pakrat!!! :icon_wink:

If you get a chance and if you have a tube screamer stick it in front of the BF and set the level on the TS @ about 3 or 4 with the drive all the way down and tell me what you think?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 27, 2012, 05:46:11 PM
It's my pleasure brotha
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on October 27, 2012, 07:30:39 PM
Just got back from the music store making the toner transfers. Should be populating tonight ;D

Could you repost the newest version with corrected parts list? Perdy please? :D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 27, 2012, 10:23:26 PM
Just got back from the music store making the toner transfers. Should be populating tonight ;D

Could you repost the newest version with corrected parts list? Perdy please? :D

I updated the layout on page 6 also rather than keep uploading to my dropbox acct... The only difference in this layout is the added jumper which can be removed along with R19 for attaching the optional noise gate and the addition of C25 - 470pF cap by R1 which if you have already etched the board you can easily solder on the back solder side of the board.

(http://dl.dropbox.com/u/11178619/BFUltra%20-%20R3.2.png)

Board Transfer
http://dl.dropbox.com/u/11178619/BFUltra%20-%20R3.2.pdf
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on October 28, 2012, 01:00:59 AM
Thanks J
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on October 28, 2012, 08:29:12 PM
*%^*(^$*$(!    I made the wrong pcb!     I cant even get started on this cursed project     :icon_mad: ALL OF MY RAGE :icon_mad:

I just realized that I can cut a trace and drill two holes it should fix it
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on October 28, 2012, 09:14:05 PM
If you are talking about the trace cut at R19, I did exactly the same thing and it's fine.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 28, 2012, 09:52:57 PM
*%^*(^$*$(!    I made the wrong pcb!     I cant even get started on this cursed project     :icon_mad: ALL OF MY RAGE :icon_mad:

I just realized that I can cut a trace and drill two holes it should fix it

There are no major changes that you can't modify on the older board layout... I try not to change the layout too much if at all for just that reason. There is also the small 470pF cap by where R2 used to be, you can just drill an extra hole by the ground trace and bend the lead over and solder it to ground for the the other lead of the cap you can use the bottom hole where R2 was along with the jumpers wire that goes in it. The leads on 470pF caps are really small so it will fit in that hole with the jumper no problem. The only other change is the added jumper between C23 and R19 incase you want to attach the noise gate addon. Again you can just drill a couple small holes between C23 and R19 right on the trace and then take an x-acto blade and remove the trace copper in between the two holes... Then solder to the traces.. Easy :icon_biggrin:

BTW -  I would recommend that you get the pedal working first and then mess with the noise gate if you feel the need... If you do it all together at one time and if something doesn't work or sound right it just adds an extra layer of complexity to trouble shooting... If you do it after you have it fully working and then you install the gate and have problems then you know exactly what it is etc..

Here is the board transfer again... It's hard to see at the bottom of the giant layout pic.
http://dl.dropbox.com/u/11178619/BFUltra%20-%20R3.2.pdf
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on October 30, 2012, 05:19:47 PM
Ok, the updated layout with noise gate instead of presence will be ready this week-end :)
I have one question for you guys: in the first layout I made, pots are (from "stomp-side" )

Gain--Vol--Pres(Gate)
Tre--Mid--Bass

If I replace the presence pot with gate pot there are a couple of jumperwires to solder but this layout has none!:
Gate--Vol--Gain
Tre---Mid--Bass

Which one you like??

Ciao :)

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: wgc on October 30, 2012, 10:41:37 PM
Sweet, thx cap!  I usually advocate "less knobs" so if you're taking requests, I'd love to see the gate as a trim pot, and 5 knobs only.  Otherwise the second is good for me...

Actually glad my parts haven't arrived yet... Gonna redo the etches of jok3rs new pcb and this new one when ready!

Thanks gentlemen for your fine work!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on October 30, 2012, 10:44:26 PM
Here's a video demoing the gain dropout.  Btw, don't let my puberty voice fool you. I'm 23 and I sound 13 :icon_lol:


Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 31, 2012, 04:14:19 AM
Here's a video demoing the gain dropout.  Btw, don't let my puberty voice fool you. I'm 23 and I sound 13 :icon_lol:




wow man, you really had me freakin out there! :o So, I ran and checked mine to make sure you had not uncovered yet another bug in the pedal that I had not noticed yet... I am VERY HAPPY ;D to report that mine does NOT do that thank God! BTW - Are you running directly into the front input of the ValveKing? It sounds as if all of the tone and lower ass end has been sucked out of it is the reason why I ask. This really should be used as a stand alone preamp in my opinion... I have ran it direct using impulses, into a power amp, into the fx return power section of a 5150 and straight into the guitar input of a couple guitar amps. Of all that I tested I really do not like the sound through the front input of a guitar amp!!! I don't know about the gain pot, that is strange?? It sounds to me like the pot reaches a certain point and then kicks on to almost full gain and turning it up beyond that point has almost no increase in gain? Anything below that point turns almost completely off? Can you measure the voltages at the drain of Q1 thru Q5 and post your findings here? I'm just curious as to what they are set at?

One thing you can do is solder the tip output jack wire to the bottom side of the board right on the 2nd lug of the gain pot. It's not going to have any gain obviously but it should act as a volume knob from the first stage and you should be able to roll it up and down without it cutting out at any point. Also you can try to solder the output jack to the output side of R4 which is the 68k resistor that leads into the 2nd stage and do the same test...  You can bias these by ear but if you get one stage that is way off range it will only get worse as you go down the line...

My guess is that one of the stages after the first stage is set wildly out of range and the gain pot is opening up the circuit only when it reaches a certain level? Or, Q1 is set wrong and it only delivers enough signal when the gain pot reaches a certain level? This may also account for the massive noise/buzz you are getting if one or two stages are really loud which leads me to believe that the problem is after the first stage somewhere because of all the noise you are getting. Normally if the first stage is set too high or low it does not introduce added noise because you are not really getting high gain at that stage. Really as a "rule" the drain voltage at each stage should be half of the source voltage on the power rail right at that stage! So, Q1, Q2 and Q3 are going to have a different source voltage than Q4, Q5 and Q6 because R6 is resisting some of the voltage going to the first three stages. Whatever voltage you are getting on the positive side of C1 (which should be 8.7v) is the source voltage for the first three stages so, you will bias those stages @ half of that voltage which would be 4.35v. On stages Q4, Q5 and Q6 you should have straight source voltage which will be whatever your power adapter is putting out and should be 9.5v ideally. So, all along the power rail from the right side (power supply side) of R6 you should have 9.5v. So, Q4 and Q5 should be biased @ 4.5v to 4.75v. And by the way, you should be using a regulated power adapter. A crappy power adapter will produce crappy results with high gain pedals... :icon_wink:

Do you have the boost switch wired up? The reason I ask is because it sounds like a low gain setting. Even at that setting you are getting a hell of a lot of noise? I know it's not boxed up but geeeesh!? I know you may be getting all of this noise because of the biasing but these high gain preamps really need shielded input/output wires! What kind of cables you use also makes a big difference! I any case, at the gain level you are reaching even unboxed with no shielded input/output cables you should have almost no noise at all...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on October 31, 2012, 06:10:33 AM
As for the bass, I know why it's not coming through and I thought I mentioned it to you. I don't have any 500k pots so I'm using a 250k till I can get one.


Here's all of my voltages.   I started with your suggested voltages and then biased by ear till it sounded best

Q1
D   4.76
S   .66
G   0

Q2
D   4.05
S   .56
G   0

Q3
D   4.05
S   .68
G   0

Q4
D   3.03
S   .60
G   0

Q5
D   4.20
S   .51
G   0

Q6
D   9.12
S   4.62
G   4.18
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 04, 2012, 12:02:33 PM
Mike, liked your vid and agree with JOK3RX that it sounds like a bit lower gain than what it should be. My build isn't perfect either but it has monstrous gain and almost no noise at all without the gate installed. I didn't box mine yet either and did not use any shielded wire, and it is biased to the voltages JOK3RX stated. I lost a week here due to hurricane Sandy (I'm on Long Island) but as soon as I clean up around here I'll check my voltages and list them for you if that would help.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 04, 2012, 12:32:59 PM
Whatever the result i'm going to keep this one and call it the orange grove because the guys at the shop say it sounds like a good Orange amp. I'll build a new one with the newest pcb and then try different fets and experiment a lil.


Good to see that you survived  ;)


EDIT   @ Jim   Is that randall emulator any closer to the top of your list? ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 04, 2012, 01:01:13 PM
Mike, I have a Randall RG100 layout if you're interested. It's not verified as far as I know, but I have all of the parts to build it.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 04, 2012, 01:57:03 PM
Awesome. That's exactly the model wanted.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 04, 2012, 04:19:08 PM
I'm not sure I can post it here, pm me your email and I'll send it to you. If JOK3RX is doing the RG100 I'd wait for that.... don't wanna step on anyone's toes here.... I do have the real schematic too somewhere, and an actual RG100 amp that I guess I could trace. I would love my Randall in a box!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 04, 2012, 05:49:33 PM
Awesome. That's exactly the model wanted.

Here's a layout made by Jacob Kokura using mensur's schematic... Probably the closest to the actual Randall. Down side is that it requires 24v but not that big of a deal if it sounds good!

http://dl.dropbox.com/u/8772719/DIY/Randall/MensurRG100schem.jpg

http://dl.dropbox.com/u/8772719/DIY/Randall/JKMensurRandall.pdf


Here's the post about it... I haven't built it, yet... But looks pretty simple and straight forward!
http://www.diystompboxes.com/smfforum/index.php?topic=91777.0
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 04, 2012, 08:17:25 PM
Awesome. I'm excited to start this build. :icon_surprised:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 04, 2012, 09:28:40 PM
That's the one I have. The only variable I see is the pot values, but I could always look inside my RG to see what they are.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 04, 2012, 10:36:34 PM
Board is etching as I'm typing ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 04, 2012, 11:25:14 PM
That's the one I have. The only variable I see is the pot values, but I could always look inside my RG to see what they are.

Mensur's values are correct other than the volume knob which I'm sure was tested with B50K instead of the original B10K... The value of pots varies from country to country like in the US a 50k pot will be called 47k in some other country...

The JFETs used on the actual Randall are 2N5484.. Everything on mensur's schematic is for the most part true to the original with the exception of some very minor tweaks and added stuff which actually look like nice improvements!

The pot values from the actual Randall factory schematic are as follows:

Gain - A50K
Vol - B10K
Treb - B50K
Mid - B2K
Bass - A50K
Pres - B2K
Note: The B50K voice pot was added and is not in the original Randall schematic. The voice knob is a sort of "fake variable capacitor" so to speak varying between 47n and 22n which I think is a cool idea!

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 05, 2012, 12:45:58 AM
Def a cool idea. I've had the parts for this project for months, but projects like the Black Forest keep me from building it  ;)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 05, 2012, 01:34:22 AM
Might want to check out the x2fet also... supposed to be a Warhead simulator


x2fet:
http://www.techniguitare.com/Fiches/X2FET-V1.pdf

http://pagesperso-orange.fr/sxsyl20/x2fet/X2FET.jpg
http://pagesperso-orange.fr/sxsyl20/x2fet/x2fet.txt
http://pagesperso-orange.fr/sxsyl20/x2fet/x2fet.gif

http://www.diystompboxes.com/smfforum/index.php?topic=70489.0
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 05, 2012, 01:42:48 AM
STOP IT    you are loading up my to build list!!! :icon_lol:   I just finished drilling the randall pcb
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 05, 2012, 01:59:52 AM
STOP IT    you are loading up my to build list!!! :icon_lol:   I just finished drilling the randall pcb

You started it..!  :P So, you don't want to see the Super Randall designed by Fortin Aplification? The Randall Satan or Natas depending on which way you are looking at it...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 05, 2012, 02:23:49 AM
Keep going... it hurts so good   :icon_lol:   im etching the x2fet atm    I see more etching going on for me tonight. gotta order more pots though :icon_sad:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 05, 2012, 08:25:08 AM
The Randall Satan is Ola Englund's signature amp? You can't even get an idea of how good the amp is because that guy can make a gorilla amp sound killer.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on November 05, 2012, 06:17:22 PM
Hi guys! I'm back :) I'm very very busy at the moment but I made a new update: added the gate pot and put a trimpot for presence..so you can decide if leave off it or not.

This is a preview, the complete pdf tomorrow  ;) It's late night here ;D

http://dl.dropbox.com/u/3511352/Black%20Forest%20Gate%2Bpres%20trim.pdf

Ciao! ;)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 05, 2012, 07:06:55 PM
I abso@#$%inlutely love this X2! I just finished biasing and testing and I cant get over how awesome it is. I like meaty obnoxious super high gain distortion. I listen and play a lot of crossover thrash metal/thrash punk, so it's perfect.

(http://i1267.photobucket.com/albums/jj545/haveyouseenhim/DSC07827.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 05, 2012, 07:43:01 PM
Great looking build Mike. I guess I need to add this one to my list now.... sigh. I have 2 weeks to complete 3 builds for the turkey day shootout and haven't even been able to order parts yet. Looks like it's gonna be a few all-nighters for me.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 05, 2012, 07:44:31 PM
@Cap I'm drooling again! Good to have you back in here  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 05, 2012, 08:38:41 PM
I abso@#$%inlutely love this X2! I just finished biasing and testing and I cant get over how awesome it is. I like meaty obnoxious super high gain distortion. I listen and play a lot of crossover thrash metal/thrash punk, so it's perfect.

(http://i1267.photobucket.com/albums/jj545/haveyouseenhim/DSC07827.jpg)

Nice job! Any sound samples? All of the sound samples I heard of it sounded like garbage so it would be good to hear a good demo... btw - did you paint the pcb?  :-\
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 05, 2012, 09:00:00 PM
I don't have a way of doing quality sound samples here at my house. I'll try to set something up later. One man's garbage is another man's tonal treasure. ;D    And yes, I painted the pcb silver and green to match the actual x2 head.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 05, 2012, 09:06:37 PM
I don't have a way of doing quality sound samples here at my house. I'll try to set something up later. One man's garbage is another man's tonal treasure. ;D    And yes, I painted the pcb silver and green to match the actual x2 head.

Cool... Reason I asked about the paint is because some paints are conductive...  What jfets did you use on the X2?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 06, 2012, 12:57:44 AM
I don't have a way of doing quality sound samples here at my house. I'll try to set something up later. One man's garbage is another man's tonal treasure. ;D    And yes, I painted the pcb silver and green to match the actual x2 head.

Cool... Reason I asked about the paint is because some paints are conductive...  What jfets did you use on the X2?

Oh wow, That didn't even cross my mind :icon_eek:   I used some j201's from tayda.    I'm getting full response out of all of my controls :icon_smile:

I really need to make an order to tayda. I had to use two massive 220n chicklets and some 47pf instead of 51pf, and that was my last B50k pots.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 06, 2012, 01:42:19 AM
47pF is fine... and I like those big green mylar caps, use them all the time!

Here is a quick sound demo of the black forest again... Pretty solid I think! Let me know what you all think? I have hearing damage so I am easily deceived... :icon_cry:

http://dl.dropbox.com/u/11178619/Noise%20Gate/Dragon%20Attack.mp3
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 06, 2012, 02:22:39 AM
God thats so meaty and heavy. I think part of my problem is that I'm running it into a PIECE OF CRAP Marshall MG cab. It lacks balls. I bought it because it was $100 and I didn't know much about cabs. :icon_redface:

I'm pretty ignorant about a lot of musical gear. I've only been playing for about 2 years.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on November 06, 2012, 03:36:27 AM
sounds @#$%ing nice!... :icon_twisted:...its got a nice tight punch to it... :icon_cool:

when i finally get my other projects together i must get round to breading these emulators .....nice work jim, ..rock on guys!!!.  \\ :icon_twisted://
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on November 06, 2012, 05:48:22 PM
@ jim: It sounds killer!  :icon_twisted: :icon_twisted: :icon_twisted:

ok, as promised:
http://dl.dropbox.com/u/3511352/Black%20Forest_1590B%20layout_gate%20version.pdf (http://dl.dropbox.com/u/3511352/Black%20Forest_1590B%20layout_gate%20version.pdf)-------> UNVERIFIED

should be ok  ;) please report errors or tell me if you need explanations. Enjoy  :)

Ciao :)

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 07, 2012, 01:13:58 AM
Thank you Cap, nice n' tidy  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 07, 2012, 08:04:33 PM
Thanks Rob! It does have a tight low end punch...

Cap - I have a spare box, I think I am gonna make a small one just to use it up and I love on-board pots so it's a win win for me!!

Meanwhile back at the Dragon's Lair I have been brewing up this beast! :icon_twisted: It has a separate board for all of the pots and switches so I can pretty much use it for any of my layouts and future layouts... It attaches to the main preamp board with 3 stand offs for the tonestack and 3 stand offs for the gain pot. Then a few wires here and there to connect some switches and the input/output jacks etc... Plus I made the layout with little holes centered in the middle of the pot diameter so before I populate the board I can use it for a drill template for the enclosure. :icon_mrgreen: There is a lot of switches because there is more than just the preamp board going in there... Mwah ha ha ha.... :icon_twisted:

(http://dl.dropbox.com/u/11178619/Noise%20Gate/Image1.jpg)

(http://dl.dropbox.com/u/11178619/Noise%20Gate/Image2.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 07, 2012, 08:55:13 PM
I think I have an idea what's going in there....  ;)  That looks great Jim, really good work!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on November 08, 2012, 07:30:02 AM
looking cool man, love the black pcb too!..very. :icon_twisted: :icon_twisted: :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 08, 2012, 11:39:43 AM
Semi-off topic but I built the X2 and I just finished my first toner transfer box etch.

(http://i1267.photobucket.com/albums/jj545/haveyouseenhim/DSC07828.jpg)
(http://i1267.photobucket.com/albums/jj545/haveyouseenhim/DSC07829.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 08, 2012, 10:22:22 PM
Looks great Mike. You're pushing out boxes like a little factory over there!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 08, 2012, 10:38:09 PM
Because I have no life :D     I finished it and made a demo today.




Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 09, 2012, 06:36:26 PM
Mike, did you ever fix your volume drop problem?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 09, 2012, 06:53:32 PM
Mike, did you ever fix your volume drop problem?

+1... Sounds like you may have a short somewhere with the gain problem? Need to see some close up pics of the board and wires back and front...

Working on the ENGL now.... I think I have the uberslut BF pretty much where I like it.. mine works nearly perfect and almost no noise even on high settings! My build list is now the ENGL, Avenger, Diezel Herbert and some sort of Marshall/BSIAB beast.. in that order. Oh and a "good" cab simulator.

I already built the AMT E1 clone which I had to guess on half of but it sounds fabulous so I am kinda doing a hybrid of that and going from the schematics of the Engl Invader... I will start a new post on that when I get it spot on.. :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 09, 2012, 08:02:19 PM
@ jim: It sounds killer!  :icon_twisted: :icon_twisted: :icon_twisted:

ok, as promised:
http://dl.dropbox.com/u/3511352/Black%20Forest_1590B%20layout_gate%20version.pdf (http://dl.dropbox.com/u/3511352/Black%20Forest_1590B%20layout_gate%20version.pdf)-------> UNVERIFIED

should be ok  ;) please report errors or tell me if you need explanations. Enjoy  :)

Ciao :)



Riccardo, what are the chances of getting you to design a layout with on-board pots, power jack and input/ouput jacks that will fit into a 1590BB?

Would have this configuration and 2 on-board switches as well. Switches would be right above the Low and Prez knobs... If you can will do it I can PM you with details and of course I wouldn't expect you to do it for free!  :icon_wink: :icon_wink: If not that is totally ok, just thought I would ask cause I suck at making layouts!  :(
(http://dl.dropbox.com/u/11178619/Paint%20-%201.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 09, 2012, 08:25:14 PM
Mike, did you ever fix your volume drop problem?

+1... Sounds like you may have a short somewhere with the gain problem? Need to see some close up pics of the board and wires back and front...

Working on the ENGL now.... I think I have the uberslut BF pretty much where I like it.. mine works nearly perfect and almost no noise even on high settings! My build list is now the ENGL, Avenger, Diezel Herbert and some sort of Marshall/BSIAB beast.. in that order. Oh and a "good" cab simulator.

I already built the AMT E1 clone which I had to guess on half of but it sounds fabulous so I am kinda doing a hybrid of that and going from the schematics of the Engl Invader... I will start a new post on that when I get it spot on.. :icon_twisted:

It may have to do with the fets I'm using. I'll do some experimenting. I know I built them right, but the only variable is the fets.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 09, 2012, 08:55:34 PM
ENGL... drool..... Diezel.... drool.......
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 09, 2012, 09:39:42 PM
Here is the schematic for the AMT E1 that I traced from some pics that somebody posted in another forum.. Had to guess at some of the values but sounds as good if not better than the BF! Has a ton of gain too and really sounds like an ENGL to me! I would say it's about 75% correct and the rest is guess work... Wasn't so bad since I have a real AMT P1 pedal and they use the same board for the E1 so what I couldn't see on the pics I just translated from my P1. So, maybe it's a hybrid of the E1 and P1... :icon_twisted: If you can make a board from a schematic then you will be in business! I have verified this as 100% working with no bugs so here ya go!

BTW - it has been adapted to use J201's since the 2SK208-R's are real hard to find and the 2SK30A-R's are even harder to find and the diodes are 1N4148's instead of BAT54 or BAT85...

(http://dl.dropbox.com/u/11178619/Like%20E1%20v4.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 09, 2012, 10:46:38 PM
Thanks JOK3RX!! I would attempt a layout, but our friend Cap would just probably make a nicer one  :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 10, 2012, 10:18:36 PM
I'm sad to report that my build is "beyond repair". I've found that the source of my problem is me being an idiot and painting the board with high heat paint. A word to the wise... BBQ paint contains conductive fibers. My entire board is conductive at this point, measures .4v, and if you touch it anywhere it squeals. Sigh.... back to the drawing board.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 10, 2012, 10:22:03 PM
I'm sad to report that my build is "beyond repair". I've found that the source of my problem is me being an idiot and painting the board with high heat paint. A word to the wise... BBQ paint contains conductive fibers. My entire board is conductive at this point, measures .4v, and if you touch it anywhere it squeals. Sigh.... back to the drawing board.

Sorry to hear that. Had a good laugh at your expense though  :icon_lol:   
I just used testors lacquer on my x2
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 10, 2012, 10:30:22 PM
Lesson learned Mike. I don't mind if you laughed, but I do feel kinda stupid  :icon_redface: I'll have a new board etched tomorrow no big deal. Removing the components from the old board should be fun......
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 10, 2012, 10:30:42 PM
@JOK3RX I'm looking at the Rev4 layout and it looks like the pad for the jumper that connects to R19 is touching the pad for D4. It is not on the older layouts.... is this a mistake?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 10, 2012, 10:37:12 PM
It's really strange that the board doesn't have continuity to itself, and the ground rail shows 0v. If I measure anywhere the top of the board itself it shows .4v, but if I measure a components ground leg, it shows 0v.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 10, 2012, 10:43:53 PM
Lesson learned Mike. I don't mind if you laughed, but I do feel kinda stupid  :icon_redface: I'll have a new board etched tomorrow no big deal. Removing the components from the old board should be fun......

It could just as easily happened to me because I painted my board without checking if it was conductive. It never even crossed my mind..    You say you feel stupid, look at it this way, you're that much smarter now.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 10, 2012, 10:58:26 PM
This is true. Not all high heat paints are conductive though, and I'm glad that's true since my Turkey day entry has a painted board and is already populated..... no problems.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 11, 2012, 01:44:42 AM
It's really strange that the board doesn't have continuity to itself, and the ground rail shows 0v. If I measure anywhere the top of the board itself it shows .4v, but if I measure a components ground leg, it shows 0v.

Yup, I think you found a mistake... :icon_redface: I owe you a beer!  :icon_mrgreen:

You guys know about this guy right? He has different color boards, bits etc... Ships real fast here is the US. He will send you a business card with your order so you don't have to go through ebay and he will give you a little discount if you order direct. No more painting boards... :P Unless you like painting them that is.. ???
http://stores.ebay.com/PCB-Laminates-Copper-Clad
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on November 11, 2012, 04:41:53 AM
JOK3RX after hearing your dragon attack clip,i think i'm heading for another soldering battle again.
Thanks
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 11, 2012, 09:06:59 AM
Thank you Jim, he's on vacation so I'll order them when he gets back. I had also built the tonepad mxr gate and painted that board as well.... it works but has a serious hum, no wonder  :icon_frown:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 11, 2012, 10:04:13 AM
Thank you Jim, he's on vacation so I'll order them when he gets back. I had also built the tonepad mxr gate and painted that board as well.... it works but has a serious hum, no wonder  :icon_frown:

Remove your parts and use this to clean your boards...Actually you can probably leave all the parts in..?

http://www.homedepot.com/buy/klean-strip-green-1-gal-odorless-mineral-spirits-gkgo75000.html#.UJ--R-TNbQQ
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 11, 2012, 10:52:36 AM
I was thinking it would be easier to keep track of the parts if I just etch new boards and transfer part by part. If I take all of the parts off, I was thinking I would just sand the paint off. I think I'll go with new boards though because the pcb will take a beating with all of the desoldering. Plus this way I'll use the new Rev4 board. Can you do me a favor and fix the error in the pcb layout?  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 11, 2012, 10:58:27 AM
By the way, you are correct that removing the presence pot and associated cap & resistor totally fixes the tonestack. Maybe you could remove it from the layout to avoid confusion and it would make the board a bit smaller. If you have moved on to better things (ENGL... drool) you could send me the DIYLC files and I'll do it if you want.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: darron on November 11, 2012, 04:00:03 PM
Where do you get that dark brown PCB you used in the top view mock? I've really been looking for some!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 11, 2012, 07:18:00 PM
Where do you get that dark brown PCB you used in the top view mock? I've really been looking for some!

7 posts down from the top there is a link.  :icon_wink:

Here it is again anyway... And it's black by the way.
http://www.ebay.com/itm/24-shts-Copper-Clad-Laminate-030-4-x-6-SS-BLACK-/160919708838?pt=LH_DefaultDomain_0&hash=item25778fe4a6
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 11, 2012, 07:28:31 PM
By the way, you are correct that removing the presence pot and associated cap & resistor totally fixes the tonestack. Maybe you could remove it from the layout to avoid confusion and it would make the board a bit smaller. If you have moved on to better things (ENGL... drool) you could send me the DIYLC files and I'll do it if you want.

Ok, here ya go... Bout as tight as I can get it!

(http://dl.dropbox.com/u/11178619/Noise%20Gate/No%20Presence%20-%20Smaller%20Footprint%20-%20small.png)


Here is the giant image so you can see it better  :icon_eek:
http://dl.dropbox.com/u/11178619/Noise%20Gate/No%20Presence%20-%20Smaller%20Footprint.png

Here is the transfer it prints to scale!
http://dl.dropbox.com/u/11178619/Noise%20Gate/smaller%20BF.pdf
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 11, 2012, 08:50:56 PM
Thanks a lot Jim, I will be rebuilding ASAP!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 11, 2012, 08:54:41 PM
Me too. I'm etching atm
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 11, 2012, 09:34:48 PM
Mike, we're like two vultures waiting to pounce!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 11, 2012, 09:52:03 PM
Mike, we're like two vultures waiting to pounce!

Yep. I just want to be able to achieve the tone from Jim's sound clips. So heavy and beastly. So far mine doesn't have good enough bass.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on November 11, 2012, 11:25:09 PM
Did you substitute any component values?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: haveyouseenhim on November 11, 2012, 11:32:09 PM
Just some of the pf caps but I was never off by more than a few pf.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: darron on November 11, 2012, 11:51:10 PM
Where do you get that dark brown PCB you used in the top view mock? I've really been looking for some!

7 posts down from the top there is a link.  :icon_wink:

Here it is again anyway... And it's black by the way.
http://www.ebay.com/itm/24-shts-Copper-Clad-Laminate-030-4-x-6-SS-BLACK-/160919708838?pt=LH_DefaultDomain_0&hash=item25778fe4a6


No no. I want the dark brown one in the mock picture : D

I was mostly kidding. But been looking for board in that colour for a long time.


That ABCfab guy is really cool though. I've got heaps of board off him.

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: GreedyFly on December 16, 2012, 02:04:14 PM
Who can transfer it to veroboard!!??
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on December 16, 2012, 03:09:30 PM
Who can transfer it to veroboard!!??

Not me man... I can barely wrap my head around diylc and Sprint! vero throws me for a loop, I don't know what the hell is going on or even where to start?

btw - I am working on a new version of this using a combination of mosfets and jfets... just fyi! I know... :icon_rolleyes: You guys are thinkin "How many times is this douche bag gonna change this thing?" and my answer would be until it's right!  :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on December 16, 2012, 04:21:45 PM
I had to order more copper board to keep up with this project  :icon_rolleyes:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on December 16, 2012, 04:54:50 PM
I had to order more copper board to keep up with this project  :icon_rolleyes:

I pretty much used one board for this whole project.. You should see it! I has jumpers, burned off pads/traces, off-board point to point.. sh!t hangin off all over the place, I even have surface mount stuff on it. It's a mess from hell! I tried to build this on bread board but after I left it sit for a few days without touching it I came back to it and didn't know wtf I was looking at? Totally lost track of it on bread board...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on December 16, 2012, 05:26:26 PM
That's ok man. I'll etch as many as it takes to get this one going  :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: kabi on January 04, 2013, 05:22:58 AM
@ jim: It sounds killer!  :icon_twisted: :icon_twisted: :icon_twisted:

ok, as promised:
http://dl.dropbox.com/u/3511352/Black%20Forest_1590B%20layout_gate%20version.pdf (http://dl.dropbox.com/u/3511352/Black%20Forest_1590B%20layout_gate%20version.pdf)-------> UNVERIFIED

should be ok  ;) please report errors or tell me if you need explanations. Enjoy  :)

Ciao :)



this looks ace, is it verified yet?

thanks in advance
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: markmcconachie on January 26, 2013, 07:55:38 PM
I built this. It is pretty awesome! I will make some sound clips soon!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 27, 2013, 02:42:06 AM
I built this. It is pretty awesome! I will make some sound clips soon!

Great!! I want to hear it..!

I will be posting all new layout/builds for Engl, Krank, SLO, VHT, Bogner, Laboga, Diezel (not Diefet), Marshall  and more... NO posting until I know they are working ::) I have been working on them for quite a while! I am using all Russian schematics since they seem to know what the hell they are doing  :icon_mrgreen:

I have so much sh!t my head is spinning!!! :icon_eek:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on January 27, 2013, 06:55:16 AM
^ cool, look forward to those man... :icon_twisted:

and the clips.. ;)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deafbutpicky on January 27, 2013, 07:02:59 AM
We want demos!!! A pedal shootout, go for it, I know you want to  :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: markmcconachie on January 27, 2013, 07:20:45 AM
Okay, I will do a shootout with what I have here...

Black Forest
AMT B2
Dr Boogie
5150 amp (i'll just use the preamp and the same cab sim stuff as the others)

I will do them in a mix so that we get the best idea of how they all blend in. :D
I will try to get time to do this tonight...

I have been considering trying to make a jfet ampeg svt preamp version too...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: meffcio on January 27, 2013, 07:52:12 AM
(i'll just use the preamp and the same cab sim stuff as the others)
Well, don't you have a mike, so you could connect the preamps directly to 5150's power amp, and record from the cabinet? Unless you'll be using impulses - they're ok.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: markmcconachie on January 27, 2013, 07:57:57 AM
I will use nebula, it's kinda like impulses but much better.

The room isn't great for micing and I can't really sound treat it or build an isolation box right now.

Trust me, there will be nothing wrong with my cab sim ;)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: hangingmonkey on January 27, 2013, 08:44:13 AM
The pedal shootout sounds like a great idea. Gonna bookmark this page and check it later. Im planning to build the blackforest and it would be great to hear what it sounds like compared to other pedals using the same gear.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: meffcio on January 27, 2013, 10:17:51 AM
I will use nebula, it's kinda like impulses but much better.

The room isn't great for micing and I can't really sound treat it or build an isolation box right now.

Trust me, there will be nothing wrong with my cab sim ;)
Can't wait!  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 27, 2013, 10:59:46 AM
I will use nebula, it's kinda like impulses but much better.

The room isn't great for micing and I can't really sound treat it or build an isolation box right now.

Trust me, there will be nothing wrong with my cab sim ;)

Which version of Nebula are you using? I've not used it before but was looking at it on their website and also over at guitarampmodeling... Which version should I get? N3 Pro Bundle 3, N3 Bundle, N2 Bundle...? There is also the FREE version, is that any good, will that work or is it severely limited?? I use impulses all the time so I'm eager to try something new... ;D  Doesn't it use impulses, I see there are a lot of Libraries on guitarampmodeling..? Sorry for all the questions...  :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: markmcconachie on January 27, 2013, 04:56:50 PM
I have nebula 3 pro bundle. There are some libraries that work with the free one but iirc, there are not so many.
Nebula is similar to impulses but more dynamic. From what I understand it kinda applies a difference impulse depending on the volume, so it captures better how the speaker reacts depending on volume. I notice a huge difference in 'feel' between this and impulses.

I started recording some of the sound samples and it's really nice to see how this compares to the other preamps. The Br Boogie and the AMT B2 lack some sort of detail in the high end. I don't know how to describe this, you will hear when I am done, but I had never noticed until comparing them directly!

When do you expect to release layouts for those other pedals?

EDIT:
This is the Nebula library that I usually use
http://cabs.kalthallen.de/
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 28, 2013, 01:16:53 AM
I have nebula 3 pro bundle. There are some libraries that work with the free one but iirc, there are not so many.
Nebula is similar to impulses but more dynamic. From what I understand it kinda applies a difference impulse depending on the volume, so it captures better how the speaker reacts depending on volume. I notice a huge difference in 'feel' between this and impulses.

I started recording some of the sound samples and it's really nice to see how this compares to the other preamps. The Br Boogie and the AMT B2 lack some sort of detail in the high end. I don't know how to describe this, you will hear when I am done, but I had never noticed until comparing them directly!

When do you expect to release layouts for those other pedals?

EDIT:
This is the Nebula library that I usually use
http://cabs.kalthallen.de/

I really would like to hear what you have come up with!  :icon_twisted:

Re: When do you expect to release layouts for those other pedals?

Here's a teaser...
(http://dl.dropbox.com/u/11178619/New%20Preamps/E3%20on-board%20pots.PNG)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: markmcconachie on January 28, 2013, 04:10:26 AM
Well, here is a rough demo I recorded of the pedel before I decided to do the comparison.

https://soundcloud.com/mark-cameron-mcconachie/black-forest-preamp-test-1/s-WW8Ta
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on January 28, 2013, 04:54:49 AM
@jim: you little teaser... 8)

@mark: sounds great man.. :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: meffcio on January 28, 2013, 05:06:57 AM
Here's a teaser...
(http://dl.dropbox.com/u/11178619/New%20Preamps/E3%20on-board%20pots.PNG)
Great layout. Looks really compact for such a circuit.  :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 28, 2013, 07:18:35 AM
Well, here is a rough demo I recorded of the pedel before I decided to do the comparison.

https://soundcloud.com/mark-cameron-mcconachie/black-forest-preamp-test-1/s-WW8Ta

Mark -

Kick @ss!  \m/  :icon_twisted:  \m/
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jogina111 on January 28, 2013, 07:41:21 AM
gutted out some of my get the j201's. The problem now are the nF and pF caps. By the way, how do this compares to the dr. Boogey?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 28, 2013, 07:45:49 AM
This is the schematic used for the ENGL 3 - It is verified working but I verified it with another layout without the on-board pots... same values as the one posted I just have not had time to build the new layout! Should work good... basically the same layout that I have already built except that the pots are on-board... If somebody has some free time can you look over it for mistakes I may have made?

You can use J201's or 2n5458's for V5 and V6

(http://dl.dropbox.com/u/11178619/New%20Preamps/ENGL%20-3-%20J0K3RX.png)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 28, 2013, 07:48:08 AM
gutted out some of my get the j201's. The problem now are the nF and pF caps. By the way, how do this compares to the dr. Boogey?

That is a matter of opinion but in my opinion there is no comparison - The engl whoops the Dr.Boogie's @ss...!

BTW - the Engl uses three 2N7000 mosfets! <-- 2N7000 still super cheap! You can also use BS170's

Notice: There is a voltage divider that comes from R23 and R24 going to the gain pot, R6, C9, R13 and R18 at around +4.5v
The 4.5v rail is the 3rd trace up from the bottom if you were wondering why it is labeled +4.5v
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: markmcconachie on January 28, 2013, 07:58:18 AM
gutted out some of my get the j201's. The problem now are the nF and pF caps. By the way, how do this compares to the dr. Boogey?

That is a matter of opinion but in my opinion there is no comparison - The engl whoops the Dr.Boogie's @ss...!

BTW - the Engl uses three 2N7000 mosfets!

Notice: There is a voltage divider that comes from R23 and R24 going to the gain pot, R6, C9, R13 and R18 at around +4.5v

I am looking forward to building this :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: markmcconachie on January 28, 2013, 08:02:37 AM
gutted out some of my get the j201's. The problem now are the nF and pF caps. By the way, how do this compares to the dr. Boogey?

I have not built the Engl, but the Black Forest (Ubershall) compairs well to the Dr Boogie. It's a totally different sound and imo sounds more amp like. It also responds much more to pick dynamics and rolling the guitar volume back.:)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 28, 2013, 08:07:34 AM
I will upload the layout board transfer as soon as a few of you look it over and check it for errors... Krank is next  :icon_twisted:

Notice: only one trimmer on the Engl!  :icon_mrgreen: Nice!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on January 28, 2013, 08:11:58 AM
^ yay 1 trimmer nice, and a good mix of fets. 8)

where is the 'sweep' on the schemo?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 28, 2013, 08:17:41 AM
^ yay 1 trimmer nice, and a good mix of fets. 8)

where is the 'sweep' on the schemo?

Rob,

Sweep is on the Krank schematic but I like it so I left it on the Engl... They both use roughly the same board design and I didn't want to have a empty space for a pot on the engl layout... I guess I could have made it a presence pot but the thing already has plenty of presence!

Sweep just makes R25 variable... Changes the characteristics of the tone stack.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on January 28, 2013, 08:34:11 AM
ahhh gotcha, cool.

i breaded the boogie recently, and i got pissed off with the trims, too variable for my liking, i also tried various tone stacks on it, but still wasn't really satisfied,

once i get my current projects done i'll defo dive into this big time, i'm still after a great hi gain tight as f... sound as well as my other distortion....thanks for sharing man. !!! \m/   :icon_twisted:  \m/
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 29, 2013, 12:25:21 AM
ahhh gotcha, cool.

i breaded the boogie recently, and i got pissed off with the trims, too variable for my liking, i also tried various tone stacks on it, but still wasn't really satisfied,

once i get my current projects done i'll defo dive into this big time, i'm still after a great hi gain tight as f... sound as well as my other distortion....thanks for sharing man. !!! \m/   :icon_twisted:  \m/

Rob,

Might try the Framus Cobra tone stack or the Blackstar ts... I am going to be trying them soon!

About your projects... when you get done = never... kinda like when I ask my wife about something and she says "oh, maybe someday" which translates to don't hold your breath..  :icon_lol:  Just kiddin of course. Keep making cool sh!t, you have my permission :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 29, 2013, 01:48:45 AM
Here is the board transfer for the Engl 3 if anybody wants it... Just print the pdf, it prints to size. Will fit in a 1590BB or a 1590B... I would stick it in a 1590BB so you have room for a tube screamer, cab simulator etc... Plus I am making a clean channel, so... up to you.

BTW: J1 and J2 are to be jumpered/connected with a wire.. can't really see it in the diagram (yellow line) because it's hidden under the pots so, I labeled it on the board :icon_wink:

PDF
http://dl.dropbox.com/u/11178619/New%20Preamps/E3%20Transfer.pdf

Image
(http://dl.dropbox.com/u/11178619/New%20Preamps/E3%20Transfer.PNG)

This thing has sh!t loads of gain and tone... NOT your sisters fuzzy wuzzy fuzzbox!  :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on January 29, 2013, 03:28:17 AM
NOT your sisters fuzzy wuzzy fuzzbox!  :icon_mrgreen:

 ;D , yeah ''when i get my projects done= never''

correct, they are never done, finished , complete, are they...always room to tinker. :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: meffcio on January 29, 2013, 05:39:49 AM
J0K3RX , you're like Santa, but a lot after the Christmas ;p
Anyway, I'd like to suggest two things:
1. Consider creating a new topic. We're no longer talking about Black Forest, but about a whole collection of your stuff, so..
2. The design in your PDF file is in a really low resolution.. While it shouldn't f*ck up things, it's still always better to have the pcb design as best as it can be. Consider using PDF creator (http://www.pdfforge.org/pdfcreator) and printing the design to a file with that software. This way the design will be in much, much better quality, and then you can use Inkscape, or other kind of software to add the rest of the stuff, like title, etc.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: hangingmonkey on January 29, 2013, 06:40:03 AM
Thanks for the layouts, more stuff to add to the list of things to build.

So, are the engl3 and black forest preamps, ie should i plug the output into the effects return of my amp?

Thanks!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: euronymous0001 on January 29, 2013, 08:20:48 AM
hey jok3rx,

just remembered this thread
http://www.diystompboxes.com/smfforum/index.php?topic=89399.80 (http://www.diystompboxes.com/smfforum/index.php?topic=89399.80)  :icon_mrgreen: :icon_mrgreen: :icon_mrgreen:

looks like i need to revisit my failed board of the krankenstein. who knows, I might make it work after 20 months of clearing my head from debugging the sucker  :P
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 29, 2013, 08:44:56 AM
hey jok3rx,

just remembered this thread
http://www.diystompboxes.com/smfforum/index.php?topic=89399.80 (http://www.diystompboxes.com/smfforum/index.php?topic=89399.80)  :icon_mrgreen: :icon_mrgreen: :icon_mrgreen:

looks like i need to revisit my failed board of the krankenstein. who knows, I might make it work after 20 months of clearing my head from debugging the sucker  :P

What jfets/mosfets were you using, J201 and 2n7000? If so, then why no trimmer on the drain of the first jfet?  

I am looking over your layout...

Edit: found a couple minor things but it looks ok? Except for no trimmer on the drain of Q1 and R2 has no value listed on your schematic? There is a very tight window on the bias of Q1 and if you don't get it just right then it's game over... Do away with the PRES pot, which is actually the "Sweep" pot and should be around 50k to 100k in series with an 18k resistor so it doesn't bottom out to nothing. Actually for trouble shooting sake I would just get rid of the pres pot and use a 33k resistor... I also see you used BS170's in place of the 2n7000's which should be fine but not sure if there are minor differences, I will have to compare data sheets...

From what I can see it looks ok?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 29, 2013, 01:29:12 PM
Thanks for the layouts, more stuff to add to the list of things to build.

So, are the engl3 and black forest preamps, ie should i plug the output into the effects return of my amp?

Thanks!

Yes, or direct for recording with cab simulation...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deafbutpicky on January 29, 2013, 01:57:39 PM
You're a busy guy J0K3RX!

As you're a specialist in those heavy things I'd really like to know your opinion about this:

http://www.diystompboxes.com/smfforum/index.php?topic=100407.0
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 29, 2013, 02:41:42 PM
You're a busy guy J0K3RX!

As you're a specialist in those heavy things I'd really like to know your opinion about this:

http://www.diystompboxes.com/smfforum/index.php?topic=100407.0

Has a nice industrial fuzz kinda sound! Heavy for sure... Not really my cup-o-tea but does sound good!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 29, 2013, 03:13:52 PM
J0K3RX , you're like Santa, but a lot after the Christmas ;p
Anyway, I'd like to suggest two things:
1. Consider creating a new topic. We're no longer talking about Black Forest, but about a whole collection of your stuff, so..
2. The design in your PDF file is in a really low resolution.. While it shouldn't f*ck up things, it's still always better to have the pcb design as best as it can be. Consider using PDF creator (http://www.pdfforge.org/pdfcreator) and printing the design to a file with that software. This way the design will be in much, much better quality, and then you can use Inkscape, or other kind of software to add the rest of the stuff, like title, etc.

Good idea about your 1 - Maybe we could start A "Everything High Gain and Related" amps, preamps, distortions, overdrives etc.. in the member section? The reason I say that is because I hate when these post get rolled to the bottom of the pile mixed in with all the other stuff. I post something and one day later it's 3 pages back etc.. So that is why I have been posting under the Black Forest thread so it's all in one place. Confusing maybe but still a one stop shop and I don't have to do forum search to find an older post.

Number 2  - You are right but I printed it and the quality is not super high res but it is plenty good enough for a perfect etch! I do use pdf creator and I am using Sprint but I can't figure out how to export just the layout/traces? I can export but have to export in color and then photo shop it and convert it to negative image then set the threshold so the traces are black and the background is white... Stupid I know but that's the only way I could figure it out... Still the image is fine and you can't see any quality issues in the printout.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: meffcio on January 29, 2013, 04:13:44 PM
Good idea about your 1 - Maybe we could start A "Everything High Gain and Related" amps, preamps, distortions, overdrives etc.. in the member section? The reason I say that is because I hate when these post get rolled to the bottom of the pile mixed in with all the other stuff. I post something and one day later it's 3 pages back etc.. So that is why I have been posting under the Black Forest thread so it's all in one place. Confusing maybe but still a one stop shop and I don't have to do forum search to find an older post.
Yes, that's the thing I really, really dislike about the forum. Most of the stuff goes to 'Building your own stompbox', and finding anything there is a pain in the a**. This subforum should be at least divided into something like 'Official designs', 'Amateur/semi-pro designs', 'Members' designs' and 'Other'. But for now you could just make a topic like 'J0K3RX's high gain stuff' or so.

Number 2  - You are right but I printed it and the quality is not super high res but it is plenty good enough for a perfect etch! I do use pdf creator and I am using Sprint but I can't figure out how to export just the layout/traces? I can export but have to export in color and then photo shop it and convert it to negative image then set the threshold so the traces are black and the background is white... Stupid I know but that's the only way I could figure it out... Still the image is fine and you can't see any quality issues in the printout.
File>Printer setup, and there you choose PDFCreator.
Then File>Print, and there in upper left corner you have a small area called 'Layer'. There you choose what do you want to print, and by clicking the coloured squares next to the layers, you can choose what colour you want those layers to be!  :) From there it's simple. You can manually move the design on the printing area, or you can center it with the upper 'Centre' button. 'Tile' gives you the ability to print a whole batch on one sheet at once. Try to experiment with all stuff in that window, as you may find something more useful.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 29, 2013, 04:32:02 PM
Good idea about your 1 - Maybe we could start A "Everything High Gain and Related" amps, preamps, distortions, overdrives etc.. in the member section? The reason I say that is because I hate when these post get rolled to the bottom of the pile mixed in with all the other stuff. I post something and one day later it's 3 pages back etc.. So that is why I have been posting under the Black Forest thread so it's all in one place. Confusing maybe but still a one stop shop and I don't have to do forum search to find an older post.
Yes, that's the thing I really, really dislike about the forum. Most of the stuff goes to 'Building your own stompbox', and finding anything there is a pain in the a**. This subforum should be at least divided into something like 'Official designs', 'Amateur/semi-pro designs', 'Members' designs' and 'Other'. But for now you could just make a topic like 'J0K3RX's high gain stuff' or so.

Number 2  - You are right but I printed it and the quality is not super high res but it is plenty good enough for a perfect etch! I do use pdf creator and I am using Sprint but I can't figure out how to export just the layout/traces? I can export but have to export in color and then photo shop it and convert it to negative image then set the threshold so the traces are black and the background is white... Stupid I know but that's the only way I could figure it out... Still the image is fine and you can't see any quality issues in the printout.
File>Printer setup, and there you choose PDFCreator.
Then File>Print, and there in upper left corner you have a small area called 'Layer'. There you choose what do you want to print, and by clicking the coloured squares next to the layers, you can choose what colour you want those layers to be!  :) From there it's simple. You can manually move the design on the printing area, or you can center it with the upper 'Centre' button. 'Tile' gives you the ability to print a whole batch on one sheet at once. Try to experiment with all stuff in that window, as you may find something more useful.

meffcio,

I love you man!!!  ;D I can't believe I never saw that!? Feeling kinda stupid but happy at the same time :icon_mrgreen:

How's this look, better?
http://dl.dropbox.com/u/11178619/New%20Preamps/E3%20Transfer.pdf
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: meffcio on January 29, 2013, 04:59:20 PM
meffcio,

I love you man!!!  ;D I can't believe I never saw that!? Feeling kinda stupid but happy at the same time :icon_mrgreen:

How's this look, better?
http://dl.dropbox.com/u/11178619/New%20Preamps/E3%20Transfer.pdf
Hah, I'm glad I could help you. Now it's perfect. :D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on January 29, 2013, 06:56:54 PM
This project has sparked my interest.  
I took the liberty of making a BOM.  Hopefully it will be of use to you, and HOPEFULLY, i didnt stuff it up!  Havent read through the thread, dont know if anything has changed since the parts layout on page 13...hell, dont even know if its still called black forrest or engl 3? :)

Let me know if you spot any errors.

Anyway, here it is:

(http://www.chromesphere.com/x/pedal/Guitar%20Effect%20Schematics%20&%20Info/ENGL3_BOM.jpg)

Paul
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 29, 2013, 10:18:49 PM
Thanks Paul (chromesphere) of course it is useful! And no, the Engl 3 is not the Black Forest... I have some ideas for the Black Forest after going over these Russian designs but I am not going to get back into that just yet.

On the Engl, it would probably be best to use 2N5458 or 2N5459 for the V5 and V6 or as we call them Q5 and Q6... J201's will work fine but the 2N5458's and 2N5459's are a lot cheaper and are better suited for the buffers. So, it would be 1 - J201/ 3 - 2N7000 / 2 - 2n5458/59.  For the mosfets, 2N7000 and BS170 can be used, there may be others? I prefer the 2N7000's myself and they are cheap as dirt and they produce a lot of wonderful gain! That is good news in my book!

Things to note:
The Russian transistors can be substituted with the following to the best of my knowledge. Are they exact? probably not, but they are close enough and will work according to articles I have read by Victor Kampf from AMT Electronics. They are matched as follows:

These are the common values used in these preamps;
KP303A = J201, BF245A
KP303B = 2N5457, BF245B
KP303E = 2N5458, 2N5459, BF245C
KP303X = J201
KPC104A = J201 x 2

Ok, here's the deal... I have a sh!t ton of these Russian preamps, distortions pedals, or whatever you want to call them and I have redesigned all of them to work with the easily obtainable parts listed above. Note: I give the original designers of these circuits FULL credit for these awesome designs and in no way do I deserve any credit for these things except for the mindless re-routing of traces and time spent...

That being said, how do we want to do this?
A. Do we want to keep posting here under this post?
B. Can we create a main topic with sub-topics and do them separately for each one?
C. Just create new topics for each one in the main user area?
D. Just create new topics for each one in the member area?
E. Don't give a sh!t...  :icon_sad:

Personally, I would like to do them under the member forum in some way.  Anybody wanna have some adventures in high gain madness???
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on January 29, 2013, 10:31:21 PM
Cool Jok3rx updated the transistors, hopefully should be good now. Let me know if anything else needs tweaking!
Paul
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on January 29, 2013, 10:43:01 PM
I just now have checked in to see about building the Black Forest after a bit of a break, but now I see a new monster is born: The Engl 3 !!
Which to to build? I'm thinking hard on the ENGL 3.... how does it compare to Black Forest?

Also, I think it's great you are coming up with a bunch of high gainers to dethrone the Dr. Boogey as top distortion dog.

It would be cool to have a sub forum for super high gainers with separate threads for each of your new projects. If not possible, maybe just have separate threads in main forum for each project and then have links at the top of each thread to each other to keep 'em connected.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 29, 2013, 10:53:37 PM
bluesdevil,

Thanks for the input!! Both pedals are different but brutal just the same...

markmcconachie did a sound demo of the BF a page back or so... sounded real good! Was hoping to hear his back to back demos of the Dr.Boogie and BF etc... Maybe he will still do it?

Here is a real crappy demo of the Engl 3... This thing has mega gain by the way!

Dry with nothing but cabsim
http://dl.dropbox.com/u/11178619/E3_test_dry_as_a_mummys_dick.mp3

Some delay for depth
http://dl.dropbox.com/u/11178619/E3_test.mp3
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on January 29, 2013, 11:42:14 PM
Hey Jim - Thanks for the ENGL 3 clips!! Sounds brutal, but quiet.... perfect!
 I might go ahead and try to cobble up parts from the BOM and see if I can get it done without having to order anything.
 I'll revisit the Black Forest info in the meantime to see what's been updated. Rock on!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on January 30, 2013, 03:23:58 AM
Noticed 470pf listed twice on the BOM for a total of 5 pieces. I think all you need is three for the circuit, if my eyeballs aren't failing me.
Thanks for all the hard work getting this all together!! I ended up having to order up a few parts, but I should have everything ready to go in a week or so.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on January 30, 2013, 03:48:39 AM
Thanks Blues, ill check / fix the BOM tomorrow at work.
Cheers!
Paul
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on January 30, 2013, 04:52:19 AM


A. Do we want to keep posting here under this post?   
B. Can we create a main topic with sub-topics and do them separately for each one?
C. Just create new topics for each one in the main user area?
D. Just create new topics for each one in the member area?  YES!!!!..
E. Don't give a sh!t...  :icon_sad: ...sometimes



ok my vote: D

go with '' JOKE3RX HI GAINERS ( ENGL3)  \m/   \m/  '' 

            '' JOKE3RX HI GAINERS ( BF)  \m/   \m/  '' 

             ''JOKE3RX HI GAINERS ( KRANK)  \m/   \m/  '' 

etc etc...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Michael80 on January 30, 2013, 07:49:18 AM
Hi guys!
First of all  J0K3RX thank you so much for this amazing pedal.I'm talking about the black forest which i'm trying to finish.
I used it in front of my amp (not the best way..i know) and this pedal comes to life when the volume pass 12 o'Clock or even better at 1 o'Clock.Compared to bypass  it's VERY loud!
When the volume is lower than the halfway it's sounds muddy and fuzzy.Any thoughts?
You wrote that you removed one resistor 470k from the volume pot as it was more quiter.Does this has something to do?
thanks!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deafbutpicky on January 30, 2013, 08:38:46 AM
Hi J0K3RX,
first of all thanks for comment.

On the seperate threads idea:
A main topic 'highgainer' with subs for each pedal would be the easiest way not to get lost
in the (black)forest of schematics. The main topic would be useful for comparison between them
and stuff related.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 30, 2013, 06:47:11 PM
Hi J0K3RX,
first of all thanks for comment.

On the seperate threads idea:
A main topic 'highgainer' with subs for each pedal would be the easiest way not to get lost
in the (black)forest of schematics. The main topic would be useful for comparison between them
and stuff related.

Totally agree! But, not up to me...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: markmcconachie on January 31, 2013, 09:35:57 AM
markmcconachie did a sound demo of the BF a page back or so... sounded real good! Was hoping to hear his back to back demos of the Dr.Boogie and BF etc... Maybe he will still do it?

I will do it this weekend, it's hard to find time through the week right now...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on January 31, 2013, 09:43:19 PM
Fixed the error on the BOM and tidied it up a bit.  Also, double checked the values again, BOM is accurate to use.
Cheers,
Paul
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 31, 2013, 10:07:44 PM
Fixed the error on the BOM and tidied it up a bit.  Also, double checked the values again, BOM is accurate to use.
Cheers,
Paul



Now if somebody would double/triple check the layout against the schematic for errors it will be almost a 100% guarantee of working! I sometimes overlook the obvious so best to have another set of eyes QA it! :icon_wink:

Edit: Paul, great youtube channel!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on January 31, 2013, 10:26:28 PM
Hi guys!
First of all  J0K3RX thank you so much for this amazing pedal.I'm talking about the black forest which i'm trying to finish.
I used it in front of my amp (not the best way..i know) and this pedal comes to life when the volume pass 12 o'Clock or even better at 1 o'Clock.Compared to bypass  it's VERY loud!
When the volume is lower than the halfway it's sounds muddy and fuzzy.Any thoughts?
You wrote that you removed one resistor 470k from the volume pot as it was more quiter.Does this has something to do?
thanks!

Sorry Michael80, overlooked your post. Not sure why it gets muddy/fuzzy lower than half way? If you are using the presence control get rid of it, causes problems with the tone stack...  if you want to try the 470k resistor or another value just attach it to lug 3 on the volume pot back to the board. Another thing is it may not be biased quite right? When you bias make sure you have the gain maxed.

Another thing you can try is a buffer circuit after output? Maybe something like SHO?
http://www.diystompboxes.com/smfforum/index.php?topic=96322.0;prev_next=next
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on January 31, 2013, 10:46:36 PM
I can verify, you know, a rangemaster, but this layout is intense.  I checked over 70% of it before my brain exploded.  This is what i found.  May or may not be correct, or maybe you have modified the circuit.  Sometimes i thought prehaps i was looking at the wrong schematic, things didnt add up:

15k on J201 source should be 1.5k
2n2 (c12) connected incorrectly.  Connected to ground on pcb layout, connected to +9v on layout.
edit: R13 on the schematic is connected to the 4.5v rail but isnt on the layout
Anyway, lets start with that.  I'm going to lie down. :|

Paul
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 01, 2013, 02:22:12 AM
Thanks Paul the source resistor was 1.5k it's just hard to see the dot so I made it 1k5...  Brain exploded  :icon_lol: And no, I have not modified the circuit except for using the J201, 2N5458/59 and the sweep pot.

Corrected, I hope! If it passes inspection I will upload transfer... I will etch it this weekend anyway and be the guinea pig ::) I already have a working one without the pots on-board so no big dealeo... By the way, I uploaded this pic right over the top of the other one so the pic a few pages back is corrected also.
(http://dl.dropbox.com/u/11178619/New%20Preamps/E3%20on-board%20pots.png)

~ Jim
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on February 01, 2013, 02:42:05 AM
Cool Jim.  There could actually have been more errors.  I just totally lost track of where i was (in more ways then one) when i was going through the circuit.

Ill check it again if you want?  Was i on the right track (apart from the 1.5k resistor) with my last post?

Paul
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on February 01, 2013, 02:51:54 AM
Thanks for checking it out, Paul.
I just etched this today! A few carefully placed drill holes on the traces should do the trick, though.
  Looking forward to getting this built up..... hurry up parts order!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 01, 2013, 04:09:30 AM
Updated transfer.. Sorry Bill!  :icon_redface:
http://dl.dropbox.com/u/11178619/New%20Preamps/E3%20Transfer.pdf
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: meffcio on February 01, 2013, 04:34:03 AM
Well, I got used to checking schematics, so I'll do it when I get home, ok?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Michael80 on February 01, 2013, 06:10:16 AM
Hi guys!
First of all  J0K3RX thank you so much for this amazing pedal.I'm talking about the black forest which i'm trying to finish.
I used it in front of my amp (not the best way..i know) and this pedal comes to life when the volume pass 12 o'Clock or even better at 1 o'Clock.Compared to bypass  it's VERY loud!
When the volume is lower than the halfway it's sounds muddy and fuzzy.Any thoughts?
You wrote that you removed one resistor 470k from the volume pot as it was more quiter.Does this has something to do?
thanks!

Sorry Michael80, overlooked your post. Not sure why it gets muddy/fuzzy lower than half way? If you are using the presence control get rid of it, causes problems with the tone stack...  if you want to try the 470k resistor or another value just attach it to lug 3 on the volume pot back to the board. Another thing is it may not be biased quite right? When you bias make sure you have the gain maxed.

Another thing you can try is a buffer circuit after output? Maybe something like SHO?
http://www.diystompboxes.com/smfforum/index.php?topic=96322.0;prev_next=next
Thanks for your reply J0K3RX .I don't have the pressence control  installed.
I tried the 470 k but beside the volume drop ,i had the same fuzzy sound until the half way.So i added a 47p cap as a filter to cut some extra highs that caused the problem and now it's much better!!I  will try some different values to find the sweet spot and re bias the trans.Also i will check your buffer idea.very interesting!
Thanks again!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 01, 2013, 06:35:20 PM
Well, I got used to checking schematics, so I'll do it when I get home, ok?

meffcio, would you be so kind!? Greatly appreciated!! I'm gonna etch it tonight either way so we will see? Other people might benefit... I am working on this format layout with all on-board pots for all of the preamps. A good thing is they are all a lot alike so it's really saving a lot of work not having to completely start over with each one.. I can use the same basic layout format and modify what needs to be changed. There are engl, bogner, krank, soldano, mesa, laboga, vht and diezel vh4 and the diezel is NOT a copy of the diefet! Also, 3 different soldanos and 2 different bogners... Lots o sh!t :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: markmcconachie on February 01, 2013, 06:55:24 PM
I just made a new enclosure for the ubershall

(http://dl.dropbox.com/u/3634915/bogner.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 01, 2013, 07:14:52 PM
markmcconachie - That looks really good man!! But, as a rule I never use actual brand/manufacturer names on my boxes..even for my own use. but, as long as it's for just your own personal use and not selling I don't see a problem... I am sure the sh!t storm will start shortly :icon_rolleyes:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Michael80 on February 03, 2013, 12:22:42 PM
Ok ...working on the BF pedal for days and finaly i'm getting somewhere. 8)Last thing to do is to find the right resistor combination for R22 & R5 acording to my guitar's pickups and it's done.
But today i discovered another issue!!(the last i hope).
I added a delay pedal to the signal ....guitar--->black forest--->delay--->amp.. and with the BF always on ,everytime i engaged the delay the signal was getting too loud about 6-8db.
Does anybody experienced that before?aAny thoughts?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 03, 2013, 01:28:02 PM
Ok ...working on the BF pedal for days and finaly i'm getting somewhere. 8)Last thing to do is to find the right resistor combination for R22 & R5 acording to my guitar's pickups and it's done.
But today i discovered another issue!!(the last i hope).
I added a delay pedal to the signal ....guitar--->black forest--->delay--->amp.. and with the BF always on ,everytime i engaged the delay the signal was getting too loud about 6-8db.
Does anybody experienced that before?aAny thoughts?

Well, I can't really say since I have not tried the bf and a delay into the front input of an amp... I'm sure somebody will know but will they respond is the question? What delay is it?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 03, 2013, 02:21:26 PM
Ok, what I have done now is I have stuck the JSX noise gate between stages 3 and 4 and it is virtually silent when not playing/betwen notes etc.. and best thing is that it doesn't clip or decay the notes at all... Takes a little of the top/high end off.. Probably a nice option for all these high gainers! Total part count = 4 with on/off switch or 4 with on/off switch and control pot...
 

Also build the cab simulator from another post and it sounds fantasticly real!! puszzle87 (lart) posted it but has since taken his pics down but, mine are still there.. The guy is a genius! Perfect for these pedals.. takes up very little room, no knobs and sounds killer! Just what I was looking for! Just runs parallel with the regular output jack and supplied with +9V, no on/off.. always on but only can tell when you are running out from it. You could probably make it way smaller with SMT!

(http://dl.dropbox.com/u/11178619/SCS%20-%201.png)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on February 03, 2013, 02:45:21 PM
right now put the whole BF/GATE/SIM  thing up as 1 schematic... ;D

but seriously, i can't wait to try this stuff....when i get my sh#t together.....when.... :icon_rolleyes:

nice one jim. :icon_twisted:

btw : just runs parallel to regular out?...are you splitting somewhere?....sorry i need more coffee. :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: caspercody on February 03, 2013, 02:57:55 PM
Can you point me to the JSX noise gate?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 03, 2013, 02:58:08 PM
right now put the whole BF/GATE/SIM  thing up as 1 schematic... ;D

but seriously, i can't wait to try this stuff....when i get my sh#t together.....when.... :icon_rolleyes:

nice one jim. :icon_twisted:

btw : just runs parallel to regular out?...are you splitting somewhere?....sorry i need more coffee. :)

Just 2 outputs coming from the main output of the preamp...

Here is a really sh!tty sample of the cab sim and the gate... I am switching the gate on and off so you can hear the diff. Excuse the playing, just testing :icon_redface:
http://dl.dropbox.com/u/11178619/New%20Preamps/E3_SCS_NG.mp3

Edit: Just fyi - I was sitting as close to the pedal as possible to get as much noise as possible... you can move away from the pedal and the hum isn't so bad!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 03, 2013, 03:00:13 PM
Can you point me to the JSX noise gate?

Best thing to do is just look up the Peavey JSX schematics, look between the 3rd and 4th stages... or google jsx noise gate. It's also somewhere back in this post in the BF stuff.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on February 03, 2013, 03:23:39 PM
sounds pukka!...

gate works a treat eh.... :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 03, 2013, 03:43:41 PM
sounds pukka!...

gate works a treat eh.... :icon_twisted:

Yeah, doesn't really work like a traditional gate so it really never clips the notes... even with the gate all the way up and playing almost clean still doesn't clip. But like I said it takes away some of the highs but you can compensate by rolling the treb knob up more...

Ummm... what is pukka?  ::) is that like puke or poop? I know I suck but that's kinda harsh don't ya think? :'(
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: meffcio on February 03, 2013, 04:04:29 PM
Sorry guys, but I can't check if the schematic and layout are consistent like i promised. I haven't got time for anything yet - gotta learn for my exams..
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 03, 2013, 04:11:38 PM
Sorry guys, but I can't check if the schematic and layout are consistent like i promised. I haven't got time for anything yet - gotta learn for my exams..

Forget those exams man and check that damn schematic/layout... immediately!  :icon_evil: I'm only jokin!  :icon_lol: No problemo...! Go study!!! 
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Michael80 on February 03, 2013, 06:19:07 PM
Ok ...working on the BF pedal for days and finaly i'm getting somewhere. 8)Last thing to do is to find the right resistor combination for R22 & R5 acording to my guitar's pickups and it's done.
But today i discovered another issue!!(the last i hope).
I added a delay pedal to the signal ....guitar--->black forest--->delay--->amp.. and with the BF always on ,everytime i engaged the delay the signal was getting too loud about 6-8db.
Does anybody experienced that before?aAny thoughts?

Well, I can't really say since I have not tried the bf and a delay into the front input of an amp... I'm sure somebody will know but will they respond is the question? What delay is it?
Its a line 6 dl4 but i also tried another one just to make sure tha it's the bf that amplifies the signal.Tried also the same chain connected direct to the power amp of an engl powerball.
same problem.... :-[
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 03, 2013, 07:02:34 PM
Ok ...working on the BF pedal for days and finaly i'm getting somewhere. 8)Last thing to do is to find the right resistor combination for R22 & R5 acording to my guitar's pickups and it's done.
But today i discovered another issue!!(the last i hope).
I added a delay pedal to the signal ....guitar--->black forest--->delay--->amp.. and with the BF always on ,everytime i engaged the delay the signal was getting too loud about 6-8db.
Does anybody experienced that before?aAny thoughts?

Well, I can't really say since I have not tried the bf and a delay into the front input of an amp... I'm sure somebody will know but will they respond is the question? What delay is it?
Its a line 6 dl4 but i also tried another one just to make sure tha it's the bf that amplifies the signal.Tried also the same chain connected direct to the power amp of an engl powerball.
same problem.... :-[

May be because I left the buffer off after the volume knob? Should be something like this... That is why I mentioned a buffer to you before. I left it off because I was trying to keep the board size down, now I think I should have added it? You can easily build it on a piece of perf board then just run into it from the center lug on the volume pot and follow the schematic.... sorry, this was a learn as ya go project for me, and still is! Pay no attention to the presence pot... :icon_wink:

Another thing is the DL4 may have level difference between bypass and effect on, may not be true bypass... Not real familiar with it but I know there are a ton of mods for the DL4..? Try to run the DL4 in the FX loop of the amp and the BF direct into the front of the amp?

(http://dl.dropbox.com/u/11178619/Noise%20Gate/Ts.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on February 04, 2013, 03:40:13 AM
UK terminology ..poached from hindu's.. ;)......meaning great/genuine/proper...

http://en.wikipedia.org/wiki/Pukka
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Michael80 on February 04, 2013, 05:42:21 AM
  J0K3RX thanks  for the schem! I will try it today and see what happens :icon_cool:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: hangingmonkey on February 04, 2013, 03:59:08 PM
Sorry for such a basic question but what does the cab sim do?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 04, 2013, 07:14:12 PM
Sorry for such a basic question but what does the cab sim do?

It enables you to run directly to a recording device and or mixer using only a preamp. It simulates a miked up Celestion V30 loaded cab... It's debatable which sounds better, obviously I think a real cab and mic is as close as you're gonna get to a real cab and mic, duh ::) But, if you're sitting in your room and don't want to wake anybody up or don't have the money to go buy a cab and mic then this is your ticket! Or, you can use software cab simulation and impulses (which I love) but I'm not gonna get into that here... Hardware cab simulation has really kinda lost it's following and dropped by the way side since the appearance of software emulation and impulses!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 04, 2013, 07:19:06 PM
UK terminology ..poached from hindu's.. ;)......meaning great/genuine/proper...

http://en.wikipedia.org/wiki/Pukka

Ah ha... I can see said the blind man :icon_eek: Pukka Grande' :icon_lol:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: hangingmonkey on February 04, 2013, 08:36:20 PM
Sorry for such a basic question but what does the cab sim do?

It enables you to run directly to a recording device and or mixer using only a preamp. It simulates a miked up Celestion V30 loaded cab... It's debatable which sounds better, obviously I think a real cab and mic is as close as you're gonna get to a real cab and mic, duh ::) But, if you're sitting in your room and don't want to wake anybody up or don't have the money to go buy a cab and mic then this is your ticket! Or, you can use software cab simulation and impulses (which I love) but I'm not gonna get into that here... Hardware cab simulation has really kinda lost it's following and dropped by the way side since the appearance of software emulation and impulses!

Thanks for explaining. So, should I make 2 outputs, one from the black forest pcb output for plugging into the return of my amp and another output - black forest pcb->cab sim->output jack for recording/mixing device?

Thanks
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 04, 2013, 10:11:52 PM
Sorry for such a basic question but what does the cab sim do?

It enables you to run directly to a recording device and or mixer using only a preamp. It simulates a miked up Celestion V30 loaded cab... It's debatable which sounds better, obviously I think a real cab and mic is as close as you're gonna get to a real cab and mic, duh ::) But, if you're sitting in your room and don't want to wake anybody up or don't have the money to go buy a cab and mic then this is your ticket! Or, you can use software cab simulation and impulses (which I love) but I'm not gonna get into that here... Hardware cab simulation has really kinda lost it's following and dropped by the way side since the appearance of software emulation and impulses!

Thanks for explaining. So, should I make 2 outputs, one from the black forest pcb output for plugging into the return of my amp and another output - black forest pcb->cab sim->output jack for recording/mixing device?

Thanks

You don't have to add any outputs to the board... Just jump an output wire and ground wire from the standard output to the cabsim board and then your 9v straight from the power jack, done! The good thing about this is that the cabsim is always on but if you are running from the standard output you will never know. Also, if you want to run out of the cabsim output and you hit bypass for the BF preamp the cabsim is still on! So, if you want to just use it for a cab simulation box then you can! You can run another preamp pedal into the BF then hit bypass for the BF board then for example, run a Dr. Boogie into it and use just the cab simulation... Hope that all makes sense?  That's the way the AMT pedals are designed also. And I think this cab sim sounds better than the AMT simulation, brighter and has more thump!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Vince_b on February 04, 2013, 10:38:17 PM
Since you're talking about cab sim... I don't know much about recording and I have a question. If I want to record on my computer with a cab sim, is it better to also use an audio interface?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 04, 2013, 10:58:05 PM
Since you're talking about cab sim... I don't know much about recording and I have a question. If I want to record on my computer with a cab sim, is it better to also use an audio interface?

You mean as apposed to straight into your sound card? I would say absolutely! I just use a crappy Line 6 GX USB interface and it works pretty good... I know there are much better out there but for $50 it does it for me, bought it used... I have seen some for like $29.00 but can't remember the brand? Whatever it was got really good reviews! I use the GX running into my PC then I use Reaper DAW and use ASIO4ALL. I hear good things about the focusrite interfaces, might get one soon?
http://us.focusrite.com/usb-audio-interfaces
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Vince_b on February 04, 2013, 11:09:07 PM
Thanks for all the informations JOK3RX.

I actually bought myself a Focusrite Scarlett 2i4 for christmas but I didn't had the time to really use it yet. From the reviews that I read it was pretty much the best unit in the price range that I wanted to pay.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on February 04, 2013, 11:47:26 PM
Hey Jim,
I was thinking about giving that cab sim a go.  Dont suppose you have a pdf copy of it for us DPI challenged individuals? :)
Paul
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 05, 2013, 01:25:17 AM
Hey Jim,
I was thinking about giving that cab sim a go.  Dont suppose you have a pdf copy of it for us DPI challenged individuals? :)
Paul

Check yer email  :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on February 05, 2013, 05:32:19 PM
(thanks Jim!) ;-)
Paul
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 05, 2013, 08:17:10 PM
(thanks Jim!) ;-)
Paul

No problem! I realized that the diagram I sent you has no resistor values or part numbers on it so you kinda have to look at the circuit to figure out what they are... I didn't draw that but it's a better layout than mine in my opinion and is the one I used. Not too hard to figure out..
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on February 05, 2013, 11:11:55 PM
No worries Jim, ill work it out, thanks again!
Paul
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on February 06, 2013, 09:08:57 PM
Hell yeah, got my parts in today for the ENGL 3 build.... will report back in a few days with results!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on February 06, 2013, 09:17:31 PM
The ENGL 3 layout really needs to be verified (visually).  Interested to see your results bluedevil!
Paul
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 07, 2013, 07:46:53 PM
Interested to see your results bluedevil!
Paul

+1 Bill (bluedevil)

Where in FL? I live in New Port Richey.

~ Jim
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on February 07, 2013, 09:37:04 PM
You're right , Paul. I better at least take a quick look before soldering!
Not feeling well today..... catching the flu or allergies are kicking my butt. I'll do my best to get a report up over the weekend.

Hey J0K3RX, I'm in Zephyrhills... hell, we're in the same county!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 07, 2013, 10:41:17 PM
You're right , Paul. I better at least take a quick look before soldering!
Not feeling well today..... catching the flu or allergies are kicking my butt. I'll do my best to get a report up over the weekend.

Hey J0K3RX, I'm in Zephyrhills... hell, we're in the same county!

Yup, about 40 miles away in-land... Howdie neighbor! :icon_mrgreen:

I have had a couple flu's already this year... still have the after affects of the last one draggin me down :P

Check the pot configuration! I am notorious for backward pots  :-[

I have another layout that doesn't have on-board pots, that's what I recorded the sound clips with.

There is one minor bug with this preamp but I am slowly figuring it out. Keep in mind I pulled this from the Russian forums so the original was designed for those cold war KP303A and KP303E transistors.. The 2N7000's are the only things that stayed the same. The bug is when you turn the volume pot on your guitar down there is an increase in noise :icon_rolleyes: At least with my guitars it does this.. Anyway, you can remedy it by putting a tube screamer or any pedal with a bypass buffer in front of it. Totally eliminates that problem 100%! So, I need to make a small buffer board of some sort to throw in front of this thing. Other than that it works excellent, well, my other layout anyway. The noise gate also works great and you can actually built it right on the switch!

For myself I was just going to build this E3 preamp, a TS-808 and the cabsim all in one box.. I like flipping on the TS anyway to tighten up the low end although it's already really tight! The TS gives it a little more scream ya know... I turn the gain all the way down on the TS and turn the level up to about 3 or 4 and it just rips! :icon_twisted: Most dudes who have Engl amps who play metal use a TS or a varaint in front of the amp anyway, same difference here. I may just make the tube screamer with a level switch and fixed resistors for the tone and gain? I don't really feel like having all those pots and once I find the sweat spot on the TS I hardly ever change the settings again, if ever....Just connect it to a stomp switch and call it "tight boost" or something? And when it's bypassed leave the buffer inline, then totally remove it from the path for true bypass. I have like 10 or more 1790ns enclosures so I may even build a crunch and clean channel? Seems kinda a logical on a preamp to have more than one channel anyway, no? blah blah blah...  :icon_twisted:   
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on February 08, 2013, 03:21:15 AM



 The bug is when you turn the volume pot on your guitar down there is an increase in noise

hmmmm...thats weird, so it doesn't like ''nothing'' going into it?...not sure what causes that, or the remedy....strange.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 08, 2013, 07:35:00 AM



 The bug is when you turn the volume pot on your guitar down there is an increase in noise

hmmmm...thats weird, so it doesn't like ''nothing'' going into it?...not sure what causes that, or the remedy....strange.

Well it like to eat tube screamers...  :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 08, 2013, 10:05:02 PM
Jok3rx,

For your noise problem, I think it is worth a shot trying a 10n cap at the input, just to make sure there is no DC across your 1M resistor.

I am really not sure it will work, but it is worth a shot...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 09, 2013, 01:36:44 AM
ok, I tried all possible fixes mentioned here and no cigar... :icon_sad: The only thing that works so far is the buffer/TS in front of the preamp.

I did audio probe this and all of the noise is coming from the 4th stage mosfet. No surprise to me! That's kinda what the BF was doing as well... So, I stuck trim pots on the source and drain and tried to even it up but no matter where I biased it I still gets the noise. Every one of these f&$#kin preamps does this same thing! There has got to be something that will fix them besides the buffer thing??? This one problem is the only thing keeping these from being really great pedals! Damn-it!!! :icon_evil:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on February 09, 2013, 02:19:05 AM
BUILD UPDATE:
All components and sockets for jfets soldered in, just gotta get the pots installed and then hope for sonic mayhem!! Unfortunately I didn't get pcb mount pots so lots of wires to deal with... and I'm dreading it, ha!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 09, 2013, 02:20:54 AM
BUILD UPDATE:
All components and sockets for jfets soldered in, just gotta get the pots installed and then hope for sonic mayhem!! Unfortunately I didn't get pcb mount pots so lots of wires to deal with... and I'm dreading it, ha!


Looking forward... I want to see if yours does what mine does.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 09, 2013, 11:36:44 AM
I just don't understand how a TS in front is fixing noise from the 4th stage... Does not make any sense to me. Is it random noise or more like high gain background noise? Does it vary with the gain knob?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 09, 2013, 01:30:22 PM
I just don't understand how a TS in front is fixing noise from the 4th stage... Does not make any sense to me. Is it random noise or more like high gain background noise? Does it vary with the gain knob?

Yeah, I really don't understand it either  ??? It seems like everything I build other than a Dr.Boogie and the AMT B1 clone has this similar issue!? The BF had it and the Engl has it or something similar..?

I started another topic about the noise here. Tried all the suggestions but if anything made things worse...  
http://www.diystompboxes.com/smfforum/index.php?topic=101250.0

Returning it to it's original state and then I will record the noise only and roll the volume on the guitar back so you can hear it. Everything on this is just as the schematic except for the substitution of KP303's with the J201's. I listen to the sound demos in the Russian forums and I don't hear any noise but they don't roll the vol knob up and down..? I think J201's are not suited for this maybe?  

Found this mod in the forum with somebody using J201's, might give it a try. The browser translation from Russian to English doesn't work so well but this is what I could make of it...
R9 - 27k / drain = 6.45v
R16 - 33k / drain = 6.5v
V4 change to BS170
R20 - 47k / drain = 5.8v

I think the noise on stage 4 is coming from the increase in gain from the previous stages... By the time it reaches the 4th stage it's already got too much gain/noise (mostly noise) so the 4th stage just gets too noisy and hums? I think it all starts from the noise produced in the first stage by the J201 and basically builds to a hum on the 4th stage? While the noise is not noticeable to the human ear in the first stage, it becomes multiplied as it goes through the following stages and becomes a problem at the 4th stage.. I think the the buffer on the first stage quiets the noise produced by the J201 a bit? Just my uneducated theory anyway....

The tube screamer or buffer doesn't completely eradicate the noise but with some minor tweaking does bring it down to a acceptable level... The down side is that it affects the over all tone as well, not very noticeable when using full high gain but if you roll the volume back on the guitar it doesn't clean up very well. Hard to explain but it doesn't sound like it's operating at it's full potential, kinda wimps out no sustain etc..  

Keep in mind - I am "VERY PICKY" and it has to be perfect or I am not happy!!! Others might not find this to be a big deal but I WANT PERFECTION!!! :icon_evil:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 09, 2013, 02:56:26 PM
You know my usual answer: Too much gain kills a pedal! It makes it noisy and sometimes unstable.

Also, the first stage is the one that is critical for noise (Frii's formula) so I would use a device with less noise. For reference a 2N5457 has about 5 times less noise density than a J201.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 09, 2013, 03:40:50 PM
You know my usual answer: Too much gain kills a pedal! It makes it noisy and sometimes unstable.

Also, the first stage is the one that is critical for noise (Frii's formula) so I would use a device with less noise. For reference a 2N5457 has about 5 times less noise density than a J201.

You are absolutely right about too much gain killing a pedal! The question is, when is it too much? I guess when it starts to sound like sh!t? I have tried the 2N5457 and it does help, a lot... but still get the noise but greatly reduced! Probably wouldn't hurt to make the 3rd stage a 2N5457 also. Like on the SLO and VHT schematics it's a J201 but same idea...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 09, 2013, 05:08:05 PM
About too much gain kills a pedal:

I have a Rocktron SilverDragon. It is not too bad (not spectacular) at high gain without the boost, but with the boost on it becomes a messy noisy thing, impossible to tame and it sounds pretty bad...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 09, 2013, 06:02:57 PM
Ok, you tried a 10nf cap added in series at the input right?

I have another idea, to address potential instabilities of the first stage: Try adding a 10pF between drain and gate of the first jfet.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on February 09, 2013, 08:48:19 PM
Okay, just finished the ENGL3 and have it hooked up to my breadboard jig (power and I/O jacks). It fired right up..... yippee, no debugging!!!!!!!
With Chromesphere's corrections, it works. I am getting a hum, probably due to such a high gain circuit exposed without any shielding.
The only difference is I changed out the J201 in Q1 for a 2n5457. Also the pots are laid out correctly... no worries there.
Only question I have is what are those two empty pad holes on power rails near bottom right corner supposed to be for.... a missing component?
     Compared to Dr. Boogey, I say this is a tighter, higher quality high gain sound. Just need to box up and put shielded wires for in/out to see if that kills that hum.
        Thanks to Jim for the great project and to Paul for the BOM and finding mistakes on the layout.

  
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 09, 2013, 08:53:33 PM
Ok, you tried a 10nf cap added in series at the input right?

I have another idea, to address potential instabilities of the first stage: Try adding a 10pF between drain and gate of the first jfet.

I'll try that tonight, didn't think of that one, yet... Thanks! I have to get my board back to a somewhat normal state, starting to look like a battle field like my black forest did at the end of it's life :-\ Hoping bluesdevil reports back with some better news with his? I want to etch that layout but kinda holding off until I hear from him. It really isn't a death sentence for this more like one of those little imperfections that just bugs the living hell out of me and ends up driving me totally insane! I could just build something like a Dr.Boogie that has stood the test of time but, I want to make new stuff! I can't just keep building the same old stuff over and over again ya know... booooring :P
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 09, 2013, 08:56:57 PM
Okay, just finished the ENGL3 and have it hooked up to my breadboard jig (power and I/O jacks). It fired right up..... yippee, no debugging!!!!!!!
With Chromesphere's corrections, it works. I am getting a hum, probably due to such a high gain circuit exposed without any shielding.
The only difference is I changed out the J201 in Q1 for a 2n5457. Also the pots are laid out correctly... no worries there.
Only question I have is what are those two empty pad holes on power rails near bottom right corner supposed to be for.... a missing component?
     Compared to Dr. Boogey, I say this is a tighter, higher quality high gain sound. Just need to box up and put shielded wires for in/out to see if that kills that hum.
        Thanks to Jim for the great project and to Paul for the BOM and finding mistakes on the layout.

  

Well that is really good news man!!!  :icon_mrgreen: Very happy it worked!!! Looks like it's etchy time at the J0K3RX ranch! :icon_wink: Those empty holes/pads are just extra.. don't know why but I always add a few extra? It's got some blistering high gain doesn't it!!? :icon_twisted: By the way, how does the sweep pot work?

Stick a tube screamer in front of it and see how you like it!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 09, 2013, 09:32:57 PM
Ok, here's the noise gate option.. I could have built it on-board but I opted to go this route instead. It mounts right on the bottom of the gate on/off switch. The 2 diodes are 1N4148..

(http://dl.dropbox.com/u/11178619/New%20Preamps/E3-NG.png)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on February 09, 2013, 11:06:28 PM
Damn, I should have waited for the layout with noise gate!! Well, I can still splice and dice my board to get it in there.
I don't know if the "sweep" control is working as it should, after giving it a longer play...... mostly just effects volume and midrange?
Ah, I don't have a tubescreamer, but I have a Les Paul with an active EMG bridge pickup I will try soon..... gotta dig it out of the closet.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 10, 2013, 12:01:44 AM
Damn, I should have waited for the layout with noise gate!! Well, I can still splice and dice my board to get it in there.
I don't know if the "sweep" control is working as it should, after giving it a longer play...... mostly just effects volume and midrange?
Ah, I don't have a tubescreamer, but I have a Les Paul with an active EMG bridge pickup I will try soon..... gotta dig it out of the closet.

You can still add the gate without too much trouble on the other layout... That's what I did on mine.

I didn't expect the sweep would do a whole lot but I thought it may make the tone stack react differently, bump the mids and or give it a scoop maybe? Probably doesn't justify a pot...? I don't like presence when it really doesn't need that either. Maybe I should move the volume over and put the gate at the end?

Trying to keep all the board layouts relatively similar for each different preamp.. A couple of them could almost use the same board all together..
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on February 10, 2013, 12:14:41 AM
Hey Jim - Yeah, it helps dial in just the right tone..... more useful than a presence control, so I would keep it on.
Gotta get this in an enclosure soon, thanks again!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on February 10, 2013, 12:17:39 AM
Sound demo please :D
Sound demo please :D
Sound demo please :D
etc
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: hangingmonkey on February 10, 2013, 03:51:35 AM
Hey JOKERX, whats the deal with the BF, i had held off because of all the updates and changes. Is the last one you uploaded the finished one?
Cheers
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 10, 2013, 07:21:56 AM
Okay, I will do a shootout with what I have here...

Black Forest
AMT B2
Dr Boogie
5150 amp (i'll just use the preamp and the same cab sim stuff as the others)

I will do them in a mix so that we get the best idea of how they all blend in. :D
I will try to get time to do this tonight...

I have been considering trying to make a jfet ampeg svt preamp version too...

Maybe when Mark gets a chance he would be so kind to do this? I would love to hear that!!! :o  Time permitting... I know people get busy. :icon_wink:

Hey JOKERX, whats the deal with the BF, i had held off because of all the updates and changes. Is the last one you uploaded the finished one?
Cheers

Hangingmonkey - I would see what version Mark used, he seems to have the best sounding build to date! Or you can keep "Hanging" until I get finished with the new version of the BF... up to you?  :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 10, 2013, 07:23:41 AM
Sound demo please :D
Sound demo please :D
Sound demo please :D
etc

+1 :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: markmcconachie on February 10, 2013, 07:36:03 AM
Sorry guys, I have been really busy :(
I 100% still plan to do the comparison though!

It's worth noting that the sound of mine can't really be compared from my sound clip, in a mix (evan a rough, crappy mix like that) guitars appear to sound really different than on their own...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: hangingmonkey on February 10, 2013, 10:31:32 AM
Okay, I will do a shootout with what I have here...

Black Forest
AMT B2
Dr Boogie
5150 amp (i'll just use the preamp and the same cab sim stuff as the others)

I will do them in a mix so that we get the best idea of how they all blend in. :D
I will try to get time to do this tonight...

I have been considering trying to make a jfet ampeg svt preamp version too...

Maybe when Mark gets a chance he would be so kind to do this? I would love to hear that!!! :o  Time permitting... I know people get busy. :icon_wink:

Hey JOKERX, whats the deal with the BF, i had held off because of all the updates and changes. Is the last one you uploaded the finished one?
Cheers

Hangingmonkey - I would see what version Mark used, he seems to have the best sounding build to date! Or you can keep "Hanging" until I get finished with the new version of the BF... up to you?  :icon_wink:

Thats cool im not in a rush. Ill hang for the new one
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: markmcconachie on February 10, 2013, 11:48:20 AM
Okay, I will do a shootout with what I have here...

Black Forest
AMT B2
Dr Boogie
5150 amp (i'll just use the preamp and the same cab sim stuff as the others)

I will do them in a mix so that we get the best idea of how they all blend in. :D
I will try to get time to do this tonight...

I have been considering trying to make a jfet ampeg svt preamp version too...

Maybe when Mark gets a chance he would be so kind to do this? I would love to hear that!!! :o  Time permitting... I know people get busy. :icon_wink:

Hey JOKERX, whats the deal with the BF, i had held off because of all the updates and changes. Is the last one you uploaded the finished one?
Cheers

Hangingmonkey - I would see what version Mark used, he seems to have the best sounding build to date! Or you can keep "Hanging" until I get finished with the new version of the BF... up to you?  :icon_wink:

I used the layout that has no presence, the only change I made I think was a 270pF cap in place of a 250pF. Also I get very very little noise from the pedel (I am not using the noise gate).
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: hangingmonkey on February 10, 2013, 02:59:10 PM
Cool, look forward to the demo!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 10, 2013, 10:05:45 PM
Ok, not the Black Forrest but it's an Uberschall... Russian version, and from working with the others this one I believe is a ball buster!!! :icon_twisted:

Anybody care to do a QA on this one?

(http://dl.dropbox.com/u/11178619/New%20Preamps/Supersonic.png)


(http://dl.dropbox.com/u/11178619/New%20Preamps/uberschall_jfet.jpg)


~ Jim
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on February 11, 2013, 02:57:29 AM
@jim: cool, just curious, does this design with the gain pot to ground, rather than the other design gain going to 4.5v have that vol pot issue?...

hmmm....cheers man.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 11, 2013, 04:00:59 AM
@jim: cool, just curious, does this design with the gain pot to ground, rather than the other design gain going to 4.5v have that vol pot issue?...

hmmm....cheers man.

Rob,

Great question! But, I have not built this one so I don't know if this one has "that vol pot issue" at all...? Although, I see what you are saying and I can tell you that I saw that myself a while ago. So, I ran the gain on the Engl 3 to ground hoping that it would have something to do with it... Nope, still did it.  :(

I do know that others (in the Russian forum) have built this using j201 and 2N5457 combinations with really good results so, we will see? I believe it will work first build just like the Engl but I hope I didn't make any small mistakes on the layout, tired and eyes play trix after a while... :icon_rolleyes: I do have it about half way built already so I will try to finish it soon... Waiting on a Tayda order for exact resistor/cap values etc.. If anybody else feel like being a Guinea pig, feel free to help out and build this one  :icon_wink: I will upload the board transfer if anybody wants it!  Still need another set of fresh eyes to check it over first..?

~ Jim
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 11, 2013, 08:25:30 AM
Actually the gain pot bottom leg should go to the polarization point of the jfet and not the ground to avoid creating DC across the lugs of the gain pot. or maybe it is a deliberate choice from the designer to have the jfet polarization changing with the gain put being turned? I doubt so though...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 11, 2013, 09:30:38 AM
Actually the gain pot bottom leg should go to the polarization point of the jfet and not the ground to avoid creating DC across the lugs of the gain pot. or maybe it is a deliberate choice from the designer to have the jfet polarization changing with the gain put being turned? I doubt so though...

So, you think I should make it like the engl then? Or, at least make the board so you can jumper it either way?

Edit: I updated the layout a few posts up... see what you think?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 11, 2013, 02:25:47 PM
Yep, I guess it is good to keep both solutions and see if it makes any difference. I am not sure it would make any type of difference you could hear though, but it just makes more sense from a design point of view.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 11, 2013, 06:31:23 PM
This one was a lot like the Uberschall so I pounded it out real quick... Thank you sir, may I have another!  :icon_twisted:

One good thing is I kinda got to double check my work on the Uber and the SLO while doing these... Pretty confident they will work! Let me know if anybody wants the transfers??

I give to you SLO-RECTO  :icon_mrgreen:

(http://dl.dropbox.com/u/11178619/New%20Preamps/SLO-RECTO.png)


(http://dl.dropbox.com/u/11178619/New%20Preamps/slo_recto_jfet.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: markmcconachie on February 11, 2013, 08:10:42 PM
After reading the AMT article about JFET emulation, am I correct in understanding that it's the additional diodes that make the black forest clean up so much with the guitar volume rolled back?

What exactly is the SLO-RECTO based on? I assume soldano and mesa rectifier, are these amps similar?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 11, 2013, 09:42:38 PM
After reading the AMT article about JFET emulation, am I correct in understanding that it's the additional diodes that make the black forest clean up so much with the guitar volume rolled back?

What exactly is the SLO-RECTO based on? I assume soldano and mesa rectifier, are these amps similar?

Yes, I think that it helps it clean up, at least from what my ears tell me.

I think the additional diodes can be added to both the SLO and the Uberschall I just posted, might do that tonight... Although, I believe schottky diodes should be used such as BAT41, BAT85 rather than the 1N4148... I was reading some obscure stuff that Victor K wrote and from the bad google translation I believe he said that the 1n4148's could be used in a pinch if that's all you could come up with.? I could have interpreted that wrong? But, all of the AMT pedals use BAT54 which is the SMD version of the BAT85...  They also use 2SK208-R or 2SK879-R... both are the same. The through hole version is 2SK30A-R... Both are crazy hard to find! They have a lot less noise than the J201's!

I think the SLO/Recto is a hybrid translation of the best of both amps? I don't really see anything dual rectifier about this as there are no power tubes??
Title: Re: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: markmcconachie on February 11, 2013, 09:46:43 PM
My wife is a native Russian speaker, if there is anything you don't find translates well, PM me and I'll get her to explain it to me. :)

Does the Dr boogie emulate power amp tubes?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 11, 2013, 09:53:53 PM
I think the diode is an attempt at making clipping the most asymmetrical as possible with a jfet (which is way less than with a tube though). I am not sure how it would help clean-up... Any pedal with too much gain does not clean-up well. I think a good clean-up is more about choosing a good gain range, just enough to have a good range of different gain sounds, without going over the level where more gain does not sound any different (when you further amplify a square wave, it is still a square wave, same sound but with more sustain and noise...)
Title: Re: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 11, 2013, 10:03:10 PM
Does the Dr boogie emulate power amp tubes?

None of these preamps emulate power tubes that I know of, just the preamp section.

I think the diodes between source and gate help round/smooth out the tone, less harsh... May be why it seems to clean up better? Or, maybe it is the power of suggestion? But, I do see what you are saying jymaze and I agree..
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 11, 2013, 11:40:46 PM
I think I should start another post for these  ???
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 12, 2013, 03:19:40 AM
Another... Boogazy = Bogner Ecstacy / Channel OD2 and OD3

Sorry, clean channel is coming...

(http://dl.dropbox.com/u/11178619/New%20Preamps/Boogazy.png)


(http://dl.dropbox.com/u/11178619/New%20Preamps/boogazzy.JPG)


~ Jim
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 12, 2013, 06:57:17 AM
There doesn't seen to be a lot of interest in this forum for this kind of stuff?  :-\  Oh well, I think I will take a break...

The few people that are interested PM me and I will keep you updated...

~ Jim
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Maik on February 12, 2013, 08:55:22 AM
Stop!!!
At least I´m interestet. This kind of stuff is the importent stuff.
Please don´t take a breake.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on February 12, 2013, 05:50:27 PM
Hey Jim - Don't get discouraged! I thinks it's a real dedicated effort you're putting in.
In the end maybe  a sound clip "shootout" between them all would stir up some builds.
I'll definitely be following this thread and hope to build up another one.  :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: meffcio on February 13, 2013, 02:02:54 AM
I'm also interested as hell, but I kinda gave up, since I don't have much free time yet (that's actually gonna change in 2 days), and I can't find the damn transistors. I have 100 pcs of 2N7000s, but there's no way of buying J201s or 2N5457/8s for normal price here.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 13, 2013, 02:15:26 AM
I'm also interested as hell, but I kinda gave up, since I don't have much free time yet (that's actually gonna change in 2 days), and I can't find the damn transistors. I have 100 pcs of 2N7000s, but there's no way of buying J201s or 2N5457/8s for normal price here.

NTE458
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on February 13, 2013, 04:31:32 AM
@jim:  don't get dis-heartened man..... not all of us are fuzz heads!!!!.. ;)

theres enough of us hi gain fans to keep you busy i'm sure!...and i'm sure weve all tried the inevitable , compulsory dr boogie..

and would like to have a better hi gainer..or 2....theres always room for \m/  :icon_twisted: \m/ stuff!!!!....



btw i know the feeling, in the sustainer thread i was practically talking to myself for several pages... ::) ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Somicide on February 13, 2013, 04:47:01 AM
Love this stuff and all you're doing, Jim.

To be fair, I'm sure a lot of folks like myself have been lurking and reading, and not posting.  IMO, 20 pages is a lot for a latecomer to take in to find out whats going on.  Heck, they may not even realize that there is more than one circuit in this bad boy; the title is now a bit misleading!  In my case, if i miss a day or two on here, I come back to several pages of catch-up.

Maybe a new thread with all layouts right up front, with a spot reserved for the above mentioned clip shootout?  I'd love to hear side by side comparisons.  Being ever the finicky distortion fan, I like to have all my options in front of me! :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 13, 2013, 06:45:49 AM
That's cool... :icon_smile: I have a lot of stuff going on right now.. My father in law is dying with cancer and it's taking it's toll on all of us. My wife is in and out crying, my mother in law is letting herself go and she collapsed from all the heart ache and not eating, sleeping etc... Wife crying some more.  :icon_cry: Not really bothering me so much that he is dying (hate to see him die) but, I am not that close to him and he is 83 years old so... everybody get's their turn ya know.. and when it's your turn it's your turn, no getting out of it! Harder to watch my wife fall apart than anything... And, we also have a son with autism who needs constant attention (which I don't mind at all because I love him more than life!) but that takes a toll as well.. My job is letting a bunch of people go, don't know who or when...  ::)  So, every now and then I get down and feel hopeless... But you gotta take it one day at a time. Hope ya all understand.. I am doing this stuff cause I love it and it also just so happens to also take my mind off all the sh!t going on in the world, if only for 30 minutes it's good!

Carry on!  :icon_wink:
God Bless!!!

~ Jim
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on February 13, 2013, 07:47:24 AM
@jim:  i feel your pain man, ive got the same painful sh*t going on in my life now too, my mum has just been diagnosed with pancreatic cancer, i'm totally gutted, she lives 250 miles from me which is a PITA , but am off to see her at the weekend and

stay with her and my brother for a few days.. its the hardest sh*t to deal with man, ive had my brother die from it too...and my son in law...and seen it from start to the inevitable end in both cases.

and now have to face this again with my mum. its @#$%ing bollocks mate!..just so you know you aint the only one out there going through this man!..

i feel helpless, but i have a good missus and friends , and them just being there  truly helps, just take it one day at a time as thats all we can do....

all the best to you +family , keep ya chin up mate. rob.

and yes, keeping busy, certainly takes your mind off it a little... ;)



Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Vince_b on February 13, 2013, 10:05:30 AM
Hey Jim, don't take a break from posting in this thread!
Although I don't actively participate, I have been following this thread since the beginning and I'm very interested by all the stuff you come up with. I'm sure this is the case of many others too.
I don't know when I will have the time to build an high gainer, but I sure will do eventually.

My thoughts are with you and your family, I hope everything is going to get better.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 15, 2013, 08:41:31 PM
@jim:  i feel your pain man, ive got the same painful sh*t going on in my life now too, my mum has just been diagnosed with pancreatic cancer, i'm totally gutted, she lives 250 miles from me which is a PITA , but am off to see her at the weekend and

stay with her and my brother for a few days.. its the hardest sh*t to deal with man, ive had my brother die from it too...and my son in law...and seen it from start to the inevitable end in both cases.

and now have to face this again with my mum. its @#$%ing bollocks mate!..just so you know you aint the only one out there going through this man!..

i feel helpless, but i have a good missus and friends , and them just being there  truly helps, just take it one day at a time as thats all we can do....

all the best to you +family , keep ya chin up mate. rob.

and yes, keeping busy, certainly takes your mind off it a little... ;)





Damn Rob! That's way more than I am dealing with bro! No matter how bad you think you have it sometimes there is always somebody who has it worse!! I really feel for ya man! I have a hard time watching people I care about in pain more than I have dealing with the pain myself! I haven't seen any of my "close" family die... That would be legendary pain!! My dad had cancer but has been clean for 12 years now and my mom is still alive and brother so what am I crying about!? Just be thankful for what I have because nobody is guaranteed tomorrow! Anyway, your words help! Hope things get better for you and your family!! Sounds like you are really going through some really tuff times!  :-\

Anyway, we all come here to forget about this other stuff (at least I do) so, let's get on with it.
I think I will try to start new posts in the member area with all of the stuff in the first post so ya'll don't have to search through 20 pages of blah blah blah BS... And, if anybody has any of their stuff they can add it too etc.. Just a new clean start, see where it goes? Thoughts?

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluebunny on February 17, 2013, 12:31:44 PM
@Jim, Rob:  Crikey fellas, sounds like you guys are in need of a bit of love from yer geeky pedal-building mates!  You've come to the right place.  And there's the rest of us moaning about this cr4ppy transistor or that bo11ox op-amp...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on February 18, 2013, 12:12:21 AM
@rob, thats terrible news...Wishing you and your family all the best mate...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 19, 2013, 02:26:28 AM
Ok, not the Black Forrest but it's an Uberschall... Russian version, and from working with the others this one I believe is a ball buster!!! :icon_twisted:

Anybody care to do a QA on this one?

(http://dl.dropbox.com/u/11178619/New%20Preamps/Supersonic.png)


(http://dl.dropbox.com/u/11178619/New%20Preamps/uberschall_jfet.jpg)


~ Jim




Report:

Built this one and tested working! Not as BIG sounding as the Black Forest and not as much gain as I was hoping for but with a little kick in the @ss with a tube screamer it does the trick... Good thing is no noise/hum and has good tone! I still have to check voltages, just biased by ear so maybe I can squeeze a bit more gain out of it or I could add a boost like the BF?  :icon_idea:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on February 19, 2013, 07:46:44 PM
Jim, whatever you do..... don't stop posting these!!! Like others have said, there are people interested in these and heavy tone "technicians" are hard to find. Please keep up the good work  :icon_twisted:

@Rob Soooo sorry to hear about your mom! We lost my dad last year to melanoma after a hard fought 3 year battle. I know what you are going through and as terrible as it is, stay strong for her. If there is anything I can do for you, just ask.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 19, 2013, 08:01:13 PM
Jim, whatever you do..... don't stop posting these!!! Like others have said, there are people interested in these and heavy tone "technicians" are hard to find. Please keep up the good work  :icon_twisted:

@Rob Soooo sorry to hear about your mom! We lost my dad last year to melanoma after a hard fought 3 year battle. I know what you are going through and as terrible as it is, stay strong for her. If there is anything I can do for you, just ask.

Where the hell you been? :icon_evil:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 19, 2013, 08:22:58 PM
Kinda disappointed with the all jfet/J201 Russian preamps.. Not even close to the preamps with the 2N7000's mosfets! Maybe because they used those Russian KPC104A freaky fets had something to do with it? I may try to retro fit the Uberschall with the 2N7000 tonight... will have to change the source and drain resistors as well.. no big deal. I'm thinking 56k drain and 43k source like all the rest of the jfet/mosfet preamps?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on February 19, 2013, 11:41:56 PM
Jim - Did you build the ENGL yet? Just wondering if you are getting a loud hum like I am.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on February 19, 2013, 11:47:06 PM
@JOK3RX   I was "out sick" for a few months with an infection in my front teeth. It was causing me to get the flu over and over. Now that I'm better I've been rewiring my studio and upgraded to a pro tools 9 rig. Calibrated a Tascam MS-16 today with a 30 year old MRL tape. It shredded pretty bad but it got the job done  :-\
I need to do some catching up to see what changes you have made, but it seems you are still on the quest for "the sound". Don't feel bad, I have an AXEFX II and I'm probably the only one in the world not satisfied with the heavy tones..... I always go back to my Randall RG100. And so, the quest continues......
It's good to see you're still working on this though. If there's anything I can do to pitch in, let me know.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 20, 2013, 02:10:57 AM
Jim - Did you build the ENGL yet? Just wondering if you are getting a loud hum like I am.


Yeah man, I built it and yes I get the loud hum... The only thing I can attribute it to is some sort of problem in the power filtering? It's not really caused by the high gain from what I can tell but more like a power hum. You can turn the gain way back on the pedal and the hum is still there full force... This is what you are getting, right? Anyway, I am working on this because if I unlock this secret then all of these Russian preamps will be bad @ss! I have asked about this in the Russian forum but I am still trying to figure out wtf they are saying? ??? Something about lowering the supply voltage on the drains of the mosfets and some other stuff that I can't figure out, yet??

Have you tried a tube screamer in front of it? Or, another pedal with non-true bypass buffers in front of it? It stops the hum almost 100% on mine with a retail $30.00 tube screamer (TS-7) in front of mine!? WTF, right!? Anyway, I don't even have to switch the TS on, it just being in front of the ENGL is good enough... no hum and the volume roll back is fixed also :-\ Confused? But, I would like to know if that fixes it for others so, if you have a pedal (any pedal) without true bypass can you give it a try?  

I really wish there were more hours in a day! I hardly have time to work on these lately... This late night stuff is bull sh!t!  :icon_evil:

Edit: BTW - The noise gate add-on almost completely removes this hum as well but takes a bit off the high end and gain.. not much though and you can compensate by raising the treble a bit and kicking a tube screamer on if you want that all out face melting gain! The way I look at these pedals is they are "preamps" (which they are) and almost every "Real Tube" preamp I have ever played I have always used a TS in front for that extra tightness and slight gain boost! Even if the preamp already has mega gain I still use the TS and roll the gain back on the preamp a bit... Most metal players I know do this even with their $5k ENGL Invader heads or Diesel VH4's... The tube screamer is one of the most valuable non-valuable devices ever created for high gain guitar! I usually always build them into my pedals anyway..

Just FYI - I have etched and drilled all of the boards for ALL of these preamps so slowly I am populating and testing them :icon_twisted: So far the Krank is the best but it has a bit of a hum also :icon_neutral:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 20, 2013, 02:33:29 AM
@JOK3RX   I was "out sick" for a few months with an infection in my front teeth. It was causing me to get the flu over and over. Now that I'm better I've been rewiring my studio and upgraded to a pro tools 9 rig. Calibrated a Tascam MS-16 today with a 30 year old MRL tape. It shredded pretty bad but it got the job done  :-\
I need to do some catching up to see what changes you have made, but it seems you are still on the quest for "the sound". Don't feel bad, I have an AXEFX II and I'm probably the only one in the world not satisfied with the heavy tones..... I always go back to my Randall RG100. And so, the quest continues......
It's good to see you're still working on this though. If there's anything I can do to pitch in, let me know.

Axe-FX II :icon_evil: B!tch... lol

I have a friend that has one and it's sick! Already been down the F@%$#D up teeth road so I know what that's like... Fortunately I am now missing half of my teeth.. or maybe that is unfortunate? I guess it's just how you choose to look at it. My mouth is half full of teeth or my mouth is half empty of teeth  :icon_mrgreen: 
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on February 20, 2013, 02:42:20 AM
Hey Jim - Still have not tried with a buffered pedal.... will report back when I do. The hum is so bad, you can hear it even when playing. Damn, it's great if not for that hum!!
The circuit is definitely tight enough for me without anything going into it, but then again I'm used to fat and sloppy fuzzes.
 Holy hell, I read back a few posts and am depressed about the cancer reports.... my mother is going through stage 4 breast cancer right now and can feel for you all.
My own health is not too good, I'm allergic to everything it seems!! I'll post on a separate thread about my current bout with Krylon painted enclosures.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 20, 2013, 02:54:55 AM
Hey Jim - Still have not tried with a buffered pedal.... will report back when I do. The hum is so bad, you can hear it even when playing. Damn, it's great if not for that hum!!
The circuit is definitely tight enough for me without anything going into it, but then again I'm used to fat and sloppy fuzzes.
 Holy hell, I read back a few posts and am depressed about the cancer reports.... my mother is going through stage 4 breast cancer right now and can feel for you all.
My own health is not too good, I'm allergic to everything it seems!! I'll post on a separate thread about my current bout with Krylon painted enclosures.

You can try a trim pot on R24. Just remove R24 and tweak the pot until you get a lower level of noise... You will have to do it by ear and find a happy medium between noise and gain. If you go too high or too low with the trimmer it will completely cut out all the sound and you will get no signal passing at all but if you find the right spot it reduces the noise greatly...  Also, you can replace R8 with a 2k resistor and R15 with a 3k resistor... These don't have to be exactly 2k and 3k, you can use like 2.2k and 2.7k or some combination. You will have to re-bias the 1st stage again after this... Did you hear my sound sample of the noise gate? It's only 2 1N4148 diodes and a 1M resistor placed between stages 3 and 4... This makes the pedal almost completely silent and it doesn't clip notes or anything like that...

Sorry to hear about your Mom!!!  :icon_cry:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 20, 2013, 03:33:10 AM
Here is the noise gate schematic.. It goes between stages 3 and 4
You can use a switch on the 1M resistor to turn it on or off or you can use a 1M/B pot to adjust the gate level.
If you use the pot, all the way off is no gate at all and basically bypassed. Or, you can hardwire it in there with a fixed resistor and have it on all the time...
It's not at all like a regular gate... There is no attack and all that, it's just instant and never clips notes or kill sustain, even at clean or low volumes..

This is based on the Peavey JSX Joe Satriani signature series preamps.
http://dl.dropbox.com/u/11178619/New%20Preamps/JSX%20Full%20Schematic.pdf

(http://dl.dropbox.com/u/11178619/New%20Preamps/Noise%20Gate.JPG)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on February 20, 2013, 07:27:44 AM
nice one jim, i'm going to try that gate on the spitty which i have on breadboard with tonestack at the mo just to see if it'll work with it....

then i'll be trying out some of these killer looking schemo's that ive been dying to try out...cool stuff man,  did you sort out your gallery yet?..

@all: thanks for the kind words guys. all the best to you & yours too. ;)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 20, 2013, 09:55:39 AM
nice one jim, i'm going to try that gate on the spitty which i have on breadboard with tonestack at the mo just to see if it'll work with it....

then i'll be trying out some of these killer looking schemo's that ive been dying to try out...cool stuff man,  did you sort out your gallery yet?..

@all: thanks for the kind words guys. all the best to you & yours too. ;)

Nope, haven't got a login for the gallary yet... Still trying to organize ::)

I was thinking about your spitfire.. I need to build it again, kinda forgot how it sounds? Actually, I still have one of the first boards I made, version 3 I think? I know it didn't have all the noise of these from what I remember.

I built a bsiab x2 also and I kinda borrowed from yours and some random schematics I have collected... Wasn't real happy with it but it didn't sound too bad and had loads of gain.. The thing I didn't like about it was that it just didn't tighten up on the lows like these others do.. Sounds fantastic for 6 string stuff and great for leads but doesn't like the sub frequencies of the 7 or 8 string for sure! Maybe you know how to tighten up the @ss end?  :icon_mrgreen:

Here's mine.. no schematic just kinda free styled it :icon_rolleyes:
(http://dl.dropbox.com/u/11178619/New%20Preamps/BSIAB%20X%20III.png)

Went sort of by this and your version 3 and added the tone stack
(http://dl.dropbox.com/u/11178619/New%20Preamps/be2_2.gif)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on February 20, 2013, 10:10:54 AM
hi jim, yeah the spitfire isn't noisey anyway...i was just curious.

ive stuck a BMT stack on the end and am crudely endlessly swapping values on it...but it does tighten it up a bit too..

might give ^ that stack a go too...cheers man.

thats mad with the extra fet before the stack...hmmmm....

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 20, 2013, 10:24:11 AM
I have ADD (attention deficit disorder) and some odd OCD (obsessive compulsive disorder) as well... Can you tell? I just go from one thing to the next and have a million ideas running through my brain all the time! I was just thinking of programmable tone stack and volume/gain from another post where some dude made a programmable tube screamer using Arduino so, you could save presets, clean, dirty etc...  :icon_eek: then I just had to slap myself and say NO!  Jeesh, WTF is wrong with me??? :icon_rolleyes:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on February 20, 2013, 11:49:48 AM
lol...yeah that sounds familiar, i have a million different ideas going on at once too...small solar projects, magnet motor ideas, joule thiefs, beer brewing, along with pedal idea stuff too...

thats why i have 7 breadboards.. ::)

i have difficulty sleeping sometimes...not enough hours in the day man..... :)

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 20, 2013, 01:33:36 PM

thats why i have 7 breadboards.. ::)

i have difficulty sleeping sometimes...not enough hours in the day man..... :)



7 bread boards? You got me beat on that one by far... I only have 2. If I build something like one of these preamps I get totally lost if I walk away from it for a day... I come back and spend an hour trying to figure out wtf is going on here?? I really need to bread board one of these so I can swap parts on the fly rather than etch a board and remove parts, add parts, cut traces, re-attach traces... by the time I get something workable my board looks like a battle field mess of sh!t with stuff hangin all over it lol! I would never post a pic of my test work :icon_redface: I would be shunned from the scene and banned from all forums :icon_lol:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on February 20, 2013, 02:28:13 PM
yeah ya gotta bread these hi gain buggers...only problem is the squeeeeeeeling when you do..

but as long as you keep in mind that it will be fine once shielded, its well worth doing for ease of modding etc.... 8)



 
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 20, 2013, 02:37:25 PM
ok, what do you all think of this?? This is the Russian Uberschall, not quite as gainy and tight as the BF or the engl but has some good heavy tone, I think? The sweep knob is super useful, can get all kinds of ranges of tone with it! Also, there is no hum on this one which is a HUGE plus!!

Pretty sure if I change C4 to 470n or 220n it will tighten up the low end... :icon_wink:

http://dl.dropbox.com/u/11178619/New%20Preamps/UBER-JFET1.mp3
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 20, 2013, 02:42:05 PM
Jok3rx,

For your BSIABX, change C6 to 100n.

It should tighten the low end enough for your chugga-chugga needs...

You are welcome!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 20, 2013, 02:48:05 PM
Jok3rx,

For your BSIABX, change C6 to 100n.

It should tighten the low end enough for your chugga-chugga needs...

You are welcome!

I'll do that! Thanks!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on February 20, 2013, 03:45:43 PM
Not as gainy and tight as the BF? No thanks!  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 20, 2013, 03:55:17 PM
Not as gainy and tight as the BF? No thanks!  ;D

That sounds kinda funny doesn't it?  :P I'm not that way, really!  :icon_lol:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on February 20, 2013, 11:02:13 PM
Hey Jim - Finally whipped out the ol'  Les Paul with the active EMG pickup. Definitely brought down the hum compared to the passive neck pup, but still need to get it quieter for anything louder than bedroom levels. Man, that guitar was made for this circuit!!
I don't have any commercial pedals with buffered bypass to try out... maybe I'll stick something simple on the breadboard to experiment with.
I'll try to figure out how to splice in that noise gate.... I'm using the first version of the ENGL3 pcb.
This is the best high gainer I've built yet, thanks again! It's hard to believe the Black Forest would be better than this.
   
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 20, 2013, 11:56:38 PM
Hey Jim - Finally whipped out the ol'  Les Paul with the active EMG pickup. Definitely brought down the hum compared to the passive neck pup, but still need to get it quieter for anything louder than bedroom levels. Man, that guitar was made for this circuit!!
I don't have any commercial pedals with buffered bypass to try out... maybe I'll stick something simple on the breadboard to experiment with.
I'll try to figure out how to splice in that noise gate.... I'm using the first version of the ENGL3 pcb.
This is the best high gainer I've built yet, thanks again! It's hard to believe the Black Forest would be better than this.
  

Bill,

I know man! The ENGL flat out MURDERS the competition and that ain't N0 J0K3! \m/ :icon_twisted: \m/

The noise gate is great but to me it's just a band-aid on the problem, still need to find that hum and kill it! You really should try a trim pot in place of R24 and dial it up or down a bit, it really reduces the noise, for me anyway! The best fix "so far" is the buffered tube screamer or whatever in front of the pedal! It makes it what you would expect or how it "should be" from such a high gain preamp... Doesn't kill the natural noise that you would normally get but doesn't hum like a high voltage transformer gettin ready to blow like it does now!

The Black Forest has a different low end growl to it but I think the Engl is better over all... Anyway, if we find out how to kill this hum then it will open the cellar door to all of these other high gain jfet/mosfet monsters!  :icon_twisted:

Edit: Gotta give all credit to the Russians for these Beasts!! I never could have (would have) come up with this sh!t myself... :icon_rolleyes:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on February 21, 2013, 12:13:27 AM
Okay, I'll mess around with a buffer and then a trim in place of r24 before hacking in the noise gate.
I get distracted real easy, but I'll try to get it done in a few days and report back.
Man, hang in there with it!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on February 21, 2013, 10:57:13 AM
I guess I should build this Engl to join the fight against hum eh?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: kabi on February 22, 2013, 07:19:21 AM
@ jim: It sounds killer!  :icon_twisted: :icon_twisted: :icon_twisted:

ok, as promised:
http://dl.dropbox.com/u/3511352/Black%20Forest_1590B%20layout_gate%20version.pdf (http://dl.dropbox.com/u/3511352/Black%20Forest_1590B%20layout_gate%20version.pdf)-------> UNVERIFIED

should be ok  ;) please report errors or tell me if you need explanations. Enjoy  :)

Ciao :)



Already etched this board for the BF, will place an order for the missing components late next week. So yes, it will take a while, but I'm digging in gentlemen so wish me luck  :)

are there any further value changes/modifications worth trying?

thanks



Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 22, 2013, 09:09:54 AM
Ok Jok3rx,

There are choices to be made, to many project... So which one you think is the best between:

1) Engl -like (jfet)

2) Engl from Russia (MOS)

3) BlackForest

I will just make one of them so I want to make the best choice...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 22, 2013, 12:05:52 PM
Ok Jok3rx,

There are choices to be made, to many project... So which one you think is the best between:

1) Engl -like (jfet)

2) Engl from Russia (MOS)

3) BlackForest

I will just make one of them so I want to make the best choice...

Ha, good question... I think #2 is over all the best but I do really like #3 of course... :icon_wink: The jfet Engl-like AMT clone doesn't sound as much like an Engl to me as the Russian jfet/mosfet version and certainly doesn't have as much gain! The Black Forest has a really unique low end growl and very percussive attack but seems not quite as good as the Russian Engl for leads.. So, I choose the Russian Engl for the following reasons

1) It sounds the best overall... It really sounds like an Engl, tons of gain, killer percussive attack, kills for leads, just flat out murders!  
2) It uses the 2N7000 mosfets which are still easy to get and cheap as dirt
3) If we can get this one working 100% then all the other jfet/mosfet based Russian preamps will most likely be fixed as well!

by the way - I have built the Krank also and it has "the hum" of course but screams just like the Engl but in a Kranky kinda way :icon_twisted:

I have not built the following but are all almost exactly like the Engl and Krank
Buzzefall - Mr.Hector
Modern SLO100
VHT
and I found a Russian jfet/mosfet based Dr.Boogey in the same design as these!

So that's 6 different pedals! YeeHaw!  :o

jymaze - I know you, you have saved a few pedal from becoming scrap and turned them into gold! I have faith in you!  :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: alexzanderepair on February 22, 2013, 12:25:33 PM
Can ya post a link to the schematic of the #2 engl from Russia (most)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 22, 2013, 12:44:01 PM
http://dl.dropbox.com/u/11178619/New%20Preamps/ENGL%20-3-%20J0K3RX.png
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 22, 2013, 12:49:54 PM
I'll put the russian Engl together then Jok3r and report. I may try to tinker around the first stage to get rid of that annoying noise you experienced.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 22, 2013, 01:20:23 PM
I'll put the russian Engl together then Jok3r and report. I may try to tinker around the first stage to get rid of that annoying noise you experienced.

 :icon_mrgreen: Thanks for jumping in the pit! You surly will experience "the hum" and maybe you will have a better idea of what is causing it and how to remedy it? I am hoping...  If you fix it you will receive "Legendary Guru" status, from me anyway!  :icon_twisted:  
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 22, 2013, 03:14:39 PM
With that type of motivation I cannot fail !
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 22, 2013, 05:19:47 PM
This is the one i'm talking about on other thread,perf is ready and will be building it today.I choose this ENGL because of your comment JOK3RX hahaha.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 22, 2013, 06:26:38 PM
This is the one i'm talking about on other thread,perf is ready and will be building it today.I choose this ENGL because of your comment JOK3RX hahaha.

Yeah, build the Russian version that jymaze posted about 5 posts back in this thread... The AMT E1 clone in the other thread works and has no issues but it doesn't have as much gain and just doesn't have a real true Engl tone. I traced it from pics posted in another forum so I had to guess at some of the parts etc..

The only thing I would change on the schematic is you might want to use a 100k trim pot, I'm not sure what the range is there? And you can mess around with different jfets for V1, V5 and V6 some are less noisy than others. You can also use BS170's instead of the 2N7000's but I like the 2N7000 the best and they are a lot cheaper than the BS170.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 22, 2013, 07:07:05 PM
Thanks! how about supply voltage is it strictly 9V? i will be using this together with my original F1 which is 12v.Should i bias V1 to 4v as per schematic or bias it to around 5.5v?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 22, 2013, 07:21:55 PM
Thanks! how about supply voltage is it strictly 9V? i will be using this together with my original F1 which is 12v.Should i bias V1 to 4v as per schematic or bias it to around 5.5v?

I don't think there would be any problems running it @ 12v providing your caps are rated as such or higher... You should bias @ half the supply voltage or close. If you are running @ 12v then it will drop by the time it reaches the 1st stage V1 because of R8 and R15, I am guessing it will be around 11v or close to that so half of that would be 5.5v. I would hope that it wouldn't throw off the bias of the mosfets but I don't know? Don't know if this is good to do but you could put a resistor in line with the + power input to drop it from 12v down to 9v and maybe put an internal switch inside the pedal so you can switch back and forth if needed.  
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 22, 2013, 07:37:19 PM
Thanks again JOK3RX,now it's soldering time.will give update as i finish this build.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 23, 2013, 06:41:36 AM
Build update as of today

(http://s14.postimage.org/b2id2v9a9/P2232206.jpg) (http://postimage.org/)
photo sharing (http://postimage.org/)
(http://s14.postimage.org/fzvxnzb9d/P2232207.jpg) (http://postimage.org/)
image sharing (http://postimage.org/)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 23, 2013, 10:21:44 AM
fretzburner - Gettin close!  :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 23, 2013, 10:44:14 PM
Now it's burning hahaha,i like it i like it i like it!!!Used 2SK117 on V1,while V5 and V6 2N5457 and 58.Will try later with 2SK117.Will house this on 1590B to match the size of my F1.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 23, 2013, 10:59:09 PM
So you used some Jfets and no MOSfets...

It will work anyway, just a little less gain. It has so much gain anyway that you won't miss it...

I think what makes the russian version different tonally from the Engl-like version is mainly the fact that there is a little more treble boost in the eq so it may make it tighter and more razor sharp, but decreases the low end growl (you can't have everything...).

Maybe there is a tonal difference between Jfets and MOSfets, but it is at best subtle a such a high gain I bet. The polarization certainly makes a difference by making the clipping more symmetrical in he russian version. It should be more aggressive and defined, but less organic, which should be more noticeable for crunch sounds. In theory the crunch sounds of the Engl-like should be a little better to get that bluesy sound.

It is all theoretical, but maybe Jok3r can confirm/infirm...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 23, 2013, 11:19:23 PM
jymaze i'm using 2N7000 on V2,V3,and V4 as per schematic.I don't have J201 right now but liked the sound as i first fire it up.Maybe i will permanently use 2SK117 on V1 and reroute my pins config which was configured to J201.

Edited my previous post to make it clear.In a hurry posting,so excited what i just created.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 23, 2013, 11:19:59 PM
The way I interpreted what fretzburner said was that he used (2SK117 on V1 and V5) or (stage 1 and stage 5) and on V6 he used or tried both a 2N5457 and a 2N5458. He then went on to say that he was going to try the 2SK117's for V1 - V5 and V6.... But I could be totally reading it wrong here...? Do that a lot :icon_confused:

Nevermind -  fretzburner beat me to it :icon_wink:

I would be inclined to go with the 2SK117's if it sounds good! I only use the J201's because that is what I have and is a kind of a multi purpose component... Keep in mind that the original Russian schematic calls for KP303A for V1 and KP303E for V5 and V6... The 2SK117 maybe be a more suitable match?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 23, 2013, 11:35:46 PM
jymaze i'm using 2N7000 on V2,V3,and V4 as per schematic.I don't have J201 right now but liked the sound as i first fire it up.Maybe i will permanently use 2SK117 on V1 and reroute my pins config which was configured to J201.

Edited my previous post to make it clear.In a hurry posting,so excited what i just created.

Whatever you used if you don't get that hum noise then by all means keep using them!!! The J201's are noisy! I hope that is what it is, let me know cause I got my mouse finger ready to click on an order of 2SK117's right now!  :icon_mrgreen:

Do you know which classification your 2SK117's are? Y: 1.2~3.0 mA, GR: 2.6~6.5 mA or BL: 6~14 mA

Please verify and you will be honored greatly!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 23, 2013, 11:51:03 PM
I probably just misread your post, sorry... But the rest of my post about pre-eq and polarization still stands at least...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 24, 2013, 12:05:33 AM
JOK3RX i still get the usual hum but the enclosure is still open no cover at the bottom.We can finalize this as i boxed it.About the transistor it's K117GR
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 24, 2013, 12:22:43 AM
JOK3RX i still get the usual hum but the enclosure is still open no cover at the bottom.We can finalize this as i boxed it.About the transistor it's K117GR

Balls! Balls! Balls!... :icon_evil: Ok, can you try a tube screamer or some sort of pedal with a buffer or bypass buffer? Just so I am not the only one who find this to work, kills the hum. I doubt if it's boxed up is gonna make maybe a minimal difference, In this case anyway... But who knows?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 24, 2013, 12:47:02 AM
How about 2SK30A? shall we consider using this?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 24, 2013, 12:49:58 AM
How about 2SK30A? shall we consider using this?

2SK30A-R would be the best possible choice from what I know... But very Rare! I can get the 2SK30A-Y all day long but the R's are really hard to find!

I am noticing the hum is there even when the gain is dialed all the way back... Seems to be a power related!?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 24, 2013, 02:09:18 AM
I closed the enclosure and there still hum and whistling at full gain.whistle gone at around 75 percent gain.Maybe i will use shielded wires.Yes 2SK30A-Y,dont have R.But i liked the sound very much.Lots of experiment should be done to lessen the hum.will try noise gate later.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 24, 2013, 02:57:10 AM
I closed the enclosure and there still hum and whistling at full gain.whistle gone at around 75 percent gain.Maybe i will use shielded wires.Yes 2SK30A-Y,dont have R.But i liked the sound very much.Lots of experiment should be done to lessen the hum.will try noise gate later.

Well the whistle is a new one... I haven't had any whistle. Hum yes, whistle no..

maybe jymaze call pull this one out of the crapper!?

Like I said a buffered pedal in front on the engl cures it for me and the noise gate also pretty much puts a lid on it but I still want to fix it! Also if you temporarily remove R24 and install a trim pot you can dial out a lot of the hum, it's a delicate balance...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 24, 2013, 06:37:26 AM
My diy noise gate makes this acceptable.Anyway the hum is comparable to my original DT-2 and GT2.These 2 pedals are noisy too.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 24, 2013, 11:06:10 AM
This whistle/hum stuff must be some oscillation on the first stage : If a buffer solves it is very much in favor of oscillations.

Make sure you try a 22pF between drain and gate and put a 100pF in parallel with the 1M pull-down resistor. It may not work, but it is easy to try.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 24, 2013, 11:13:33 AM
This is a good informative thread that was started back in early 2011 by brymus (Bryan G) who got the Russian Krank from GTlabs working. The Krankenstien is almost the same as the Engl so whatever applies to that most likely will apply to the Engl as well. A lot of notes taken and good rundown... He has not been active in quite a long time so I doubt we will get any answers from him, but who knows? And By the way, I also built the Krank and it has the same hum as the Engl so maybe this is it???

http://www.diystompboxes.com/smfforum/index.php?topic=89399.0

Read post #6... Is this what we are experiencing with the Engl maybe? If so, then he said that fixed it...

Edit: jymaze - I will try your suggestions. In any case I really think these need the quietest cleanest power possible!? Like I said I can hear the hum or hiss with the gain all the way down and the volume down so I am not sure about the oscillation?  
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 24, 2013, 12:48:23 PM
Volume of the pedal all the way down you mean?

Is the noise the same with guitar plugged or unplugged?

Maybe the ESR of these 100uf is just too much for a circuit with such poor PSRR. The post you refer to is right: Using 10uF caps is enough decoupling and the lower ESR is beneficial. I would put a 22nF poly cap across the first stage's electrolytic too.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 24, 2013, 06:39:43 PM
I just tried to power this with the original adaptor from my F1 which is 12v and it is really good no noise gain 0-25 and guitar vol full,while gain max and guitar volume zero no hum except the whistle which started as i closed the enclosure cover.When i first fire this build(the pcb is still halfway out of the enclosure)i did not experience the whistle.Will check my wiring as experienced in my past build with mercury box.
Note: i did not re-bias V1 for 12v use,i just test it randomly to check if it tames the hum and it really improve.Maybe a lot better if biased to 4v.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 24, 2013, 08:42:10 PM
I just tried to power this with the original adaptor from my F1 which is 12v and it is really good no noise gain 0-25 and guitar vol full,while gain max and guitar volume zero no hum except the whistle which started as i closed the enclosure cover.When i first fire this build(the pcb is still halfway out of the enclosure)i did not experience the whistle.Will check my wiring as experienced in my past build with mercury box.
Note: i did not re-bias V1 for 12v use,i just test it randomly to check if it tames the hum and it really improve.Maybe a lot better if biased to 4v.

Interesting! I will try mine @ 18v since I don't have a 12v adapter at the moment... I have gotten the high pitched whistle before with other high gainers.. usually something to do with the wiring.. Make sure the output wires and the input wires are not crossing over each other and make sure the wires aren't under or over the board anywhere... Shielded wire of course, and the wires going to the gain pot can be noisy/squeal

Edit: I have the schematic for the AMT V1 by the way... Some interesting stuff under the hood, I like the FX loop! Don't really understand all the auxiliary power outputs but whatever...?

How do you like the mercury box? I have the VST emulation of that in TH2 and I really like it! Would love to know what's inside the Burning Box and maybe even the Taxi Drive!! The Brunetti amp models are awesome!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 25, 2013, 12:33:27 AM
Liked the mercury box too high gain OD that will sound like this ENGL but lesser gain than ENGL but can do light OD tones on lower gain settings.About this Engl did changed the 4.5v cap to 10uf tant and the 2.2uf tant on V1,add 100ohm resistor at 9v line.i can hear improvements(tolerable for me) and the whistling sound too.Will change later other caps to 47uf,22uf,22uf as per krankenstien schematic posted by Brymus.Will still add 22pf caps as jmaze suggested.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: meffcio on February 25, 2013, 08:04:16 AM
Build update as of today

(http://s14.postimage.org/b2id2v9a9/P2232206.jpg) (http://postimage.org/)
photo sharing (http://postimage.org/)
(http://s14.postimage.org/fzvxnzb9d/P2232207.jpg) (http://postimage.org/)
image sharing (http://postimage.org/)

How do you do traces like that? Do you tin each and every pad used?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 25, 2013, 08:21:32 AM
Yes i solder all components then do the routing by soldering.I'm used to this because i'm lazy doing pcb drawing then etching just for one build or two.It's like hand wired point to point amp style.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on February 25, 2013, 08:35:03 AM
@fretz:  looks cool, i'd get lost doing that.. :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 25, 2013, 09:11:37 AM
@fretz:  looks cool, i'd get lost doing that.. :)
Just like a puzzle or scrabble deadastronaut but i have to just to build my own pedals.And it's rewarding in the end just like this engl very contented with the result.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on February 25, 2013, 09:26:53 AM
cool, so is the hum/pot noise issue sorted then?...i'm just finishing up my reverb so i'll have a clear breadboard to try this as well soon... :icon_twisted:

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 25, 2013, 06:49:55 PM
I built the long board Engl with the on-board pots last night and it seems a little less noisy than my last build which was kinda just thrown together and all the pots were attached by wire... I also used smd tantalum caps mounted/soldered directly to the solder side of the board for C17 and C18. I may change C10 and C5 also. Still getting noise with the volume roll back on the guitar and a low hum but not nearly as bad as before.

Caps like this but the ones I used are 50v - 10uF for C18 and 22uF for C17
(http://www.embeddedprojects.org/components/com_virtuemart/shop_image/product/_SMD_Capacitor_4cb8736a50f87.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 26, 2013, 01:49:12 AM
Ok, you can run this @ 18v, my caps are all rate @ 50v so no problems there... I tried it tonight but still the same issue with the noise. 18v seems to open this up a bit and give it a more tube like sound but it already sounded tube like before so... Gotta get rid of the hum and then this will be GOLD!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on February 26, 2013, 05:45:18 AM
I've noticed in my tube to fet builds that bf245c kinda kills a lot of hum and hiss. It's low gain fet, but it's worth a try.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 26, 2013, 06:48:21 AM
Yes JOK3RX giving it higher voltage supply sounds huge and tube-like but increase noise too.My build now almost tolerable noise but still stronger tha normal.Used shielded wires on input and output.Will change gain wires too later and make it shorter.Gain up to 60 percent is useable now.Still experimenting.Changed back to 100uf on C10 and C17.C5 is still 22uf tant while C18 is 10uf tant.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 26, 2013, 08:35:44 AM
Yes JOK3RX giving it higher voltage supply sounds huge and tube-like but increase noise too.My build now almost tolerable noise but still stronger tha normal.Used shielded wires on input and output.Will change gain wires too later and make it shorter.Gain up to 60 percent is useable now.Still experimenting.Changed back to 100uf on C10 and C17.C5 is still 22uf tant while C18 is 10uf tant.

I didn't get an increase in noise with increased voltage, just the same noise... I can tame it down to almost nothing by adjusting R24/the noise get and a buffered pedal in front of it but that ain't a fix, just a band-aid....
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 26, 2013, 11:34:01 PM
Yes JOK3RX giving it higher voltage supply sounds huge and tube-like but increase noise too.My build now almost tolerable noise but still stronger tha normal.Used shielded wires on input and output.Will change gain wires too later and make it shorter.Gain up to 60 percent is useable now.Still experimenting.Changed back to 100uf on C10 and C17.C5 is still 22uf tant while C18 is 10uf tant.

Hey fretz, I think I am on to something here! Try this - Remove C3 all together and use a 2N5457 for the 1st stage and tell me what you think!? Almost fixed, I think :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 27, 2013, 12:07:51 AM
Just did a quick fix because time now is limited just removed the 22uf cap and the rest still stock yes it did lowers the noise level.But seems the gain is lowered too without the cap.Don't checked the bias if still 4v without the cap.Maybe later if have enough time.
Thanks JOK3RX for the tips.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 27, 2013, 12:24:40 AM
Just did a quick fix because time now is limited just removed the 22uf cap and the rest still stock yes it did lowers the noise level.But seems the gain is lowered too without the cap.Don't checked the bias if still 4v without the cap.Maybe later if have enough time.
Thanks JOK3RX for the tips.

Ok, try a 220nF cap for C3 and did you notice that C2 is a 220nF cap? Is this a mistake, maybe? Shouldn't it be more like 22nF or 47nF??? Anyway I lowered C2 to 47nF like on a regular Engl tube amp schematic and even better!! It's getting there!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 27, 2013, 12:43:11 AM
That 220nf C2 is something to think about hahaha. Now lots of things to do on my free time JOK3RX.Will investigate that later.We're getting close.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 27, 2013, 12:21:49 PM
That 220nf C2 is something to think about hahaha. Now lots of things to do on my free time JOK3RX.Will investigate that later.We're getting close.

I really think that C2 - 220nF was a mistake on the schematic! I stuck a 47nF in there like on almost all Engls... I looked at all of the other similar preamps and non of them are that far off, actually they are the same as the actual tube preamps they are emulating, except for this one!?

I am going to try to copy/convert the first stage values to the AMT E1 I traced a long time ago. That one had no issues other than it didn't have as much gain (probably due to it not using the 2N7000's) but there was no hum or noise with it at all.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on February 27, 2013, 06:35:50 PM
Already tried changing C2 to 22nf problem still the same and almost same sound.placed back 220uf in the circuit.Larger amount of noise starts at the 3rd mosfet or V4.Signal is stronger at the base of V4.Maybe 33k is too small from V3 to V4 line.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 27, 2013, 07:10:37 PM
Already tried changing C2 to 22nf problem still the same and almost same sound.placed back 220uf in the circuit.Larger amount of noise starts at the 3rd mosfet or V4.Signal is stronger at the base of V4.Maybe 33k is too small from V3 to V4 line.

yup... try 100k for R19? Some values are scaled down by x10 and others are not... Some sort of mathematical mind f__k theory that I am not getting? :icon_redface:

The real tube preamp schematic goes something like C14 - 47n / R18 - 470k / R19 - 330k

Some of the schematic follows this divide by 10 formula and other parts don't? Got me?  ???
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 27, 2013, 09:09:35 PM
I did some quick calculation and changing C2 from 22n to 47n should not change the bandwidth for a 7-string, you can even reduce to 22n for a 6-string. It must be a mistake because it is way over sized. Having 22 or 47 can only be better than 220n because you reduce frequencies of motor-boating type of noise. I would choose 22n, way enough.

On the other hand changing C3 to anything lower than 4.7u makes a bass cut for the stage. 22u is way too big though. I would say 4.7u is adequately sized.

There are some circuit optimization you can try, it optimizes the gain structure, and provides a better biasing for the MOS which means less noise:

A. Optimization of gain structure (less gain wasted, less degradation of the noise floor), should be the same voicing or very close:

1) jumper instead of R5
2) change R6 to 100k
3) jumper for R12
4) R13 to 47k


B. Better biasing of the devices to get better noise figure:

1) change R10 to 22k and C8 to 220n
2) change R17 to 10k
3) change R21 to 10k
4) change R22 to 10k

C. Get rid of some gain (just a little, nothing horrible, I know it makes you nervous): Change R20 to 10k

I think it should make it quieter and keep the voicing. Let me know if it works, it should get things better, trust me.

I still think that, even after all that, there will be noise because there is just a tad too much gain in this circuit and it may have to be tweaked too.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 27, 2013, 10:07:43 PM
I did some quick calculation and changing C2 from 22n to 47n should not change the bandwidth for a 7-string, you can even reduce to 22n for a 6-string. It must be a mistake because it is way over sized. Having 22 or 47 can only be better than 220n because you reduce frequencies of motor-boating type of noise. I would choose 22n, way enough.

On the other hand changing C3 to anything lower than 4.7u makes a bass cut for the stage. 22u is way too big though. I would say 4.7u is adequately sized.

There are some circuit optimization you can try, it optimizes the gain structure, and provides a better biasing for the MOS which means less noise:

A. Optimization of gain structure (less gain wasted, less degradation of the noise floor), should be the same voicing or very close:

1) jumper instead of R5
2) change R6 to 100k
3) jumper for R12
4) R13 to 47k


B. Better biasing of the devices to get better noise figure:

1) change R10 to 22k and C8 to 220n
2) change R17 to 10k
3) change R21 to 10k
4) change R22 to 10k

C. Get rid of some gain (just a little, nothing horrible, I know it makes you nervous): Change R20 to 10k

I think it should make it quieter and keep the voicing. Let me know if it works, it should get things better, trust me.

I still think that, even after all that, there will be noise because there is just a tad too much gain in this circuit and it may have to be tweaked too.

jymaze - you are right about C2, I tried 22n and 47n and not much if any noticeable difference between them.. So it's a go on that and it does sound better than 220n. Same goes for C3 - 4.7u and reduces the noise considerably... I actually tried a 470n and then a 1u there but it made it a little too tight for me (never thought I would hear myself say that!) and Lord knows it's already tight anyway... I think I settled on a 2.2u but I will try a 4.7u also.

Ok, on the R10/R17/R21/R22 are you sure that isn't going to throw off the bias of those? Remember there are no trim pots on these! As for R20 I am fine with that and I can do with a little less gain, not a problem because it has plenty of gain to burn like you say..! The only thing that makes me a bit nervous is the drastic changes to the source resistance of the mosfets, hoping it doesn't require changing the drain resistors? But, I am gonna do all of this as you say anyway  :icon_wink:

Over all I had this thing almost noiseless last night but there was still a slight increase in hum when lowering the vol pot on the guitar and that my friend BUGS THE LIVING HELL OUT OF ME!!!  :icon_evil:

Ok, off to solder land I go... wish me luck :icon_rolleyes:

Edit: Note to self: Since yo dumb @ss don't like to bread board these preamps, next time socket every damn component!   :P
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 27, 2013, 11:42:50 PM
Jok3rx, you are right, I forgot there was no trimpots... I am just used to these being always there... You can try to just do the mod for the first of the mosfets since it dominates the noise figure then 10k at source and about 15k at drain, you have to change the cap too, as stated) and see if it is useful to you at least. You will loose a little gain, but it is ok.

My bad... The other tweaks still stand nonetheless
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: nordine on February 28, 2013, 12:16:01 AM
Hey good people, there seems to be happening cool stuff here  ;)

i wanted to know the main differences in tone in both circuits Black Forest and Engl3.. or maybe, what are they suited better for... for example, which one does a better djent tone? that kind of stuff... cheers!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 28, 2013, 12:53:37 AM
Hey good people, there seems to be happening cool stuff here  ;)

i wanted to know the main differences in tone in both circuits Black Forest and Engl3.. or maybe, what are they suited better for... for example, which one does a better djent tone? that kind of stuff... cheers!

djent - engl... Although, the Black Forest is not to be laughed at either! Truth is both would be very good but a lot of times they (guitar players) roll back the gain on the preamp to get that djent tone...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 28, 2013, 01:29:45 AM
Jok3rx, you are right, I forgot there was no trimpots... I am just used to these being always there... You can try to just do the mod for the first of the mosfets since it dominates the noise figure then 10k at source and about 15k at drain, you have to change the cap too, as stated) and see if it is useful to you at least. You will loose a little gain, but it is ok.

My bad... The other tweaks still stand nonetheless

Wow... Diggin a deep hole here! Gettin worse and worse. sounds very thin and mostly just mids not to mention, for some weird reason this made the tone stack almost totally non-functional and my mid knob has now become some sort of volume knob ???

Doing this is like chasing a greasy olive around your plate with a fork trying to stab it but it escapes every time and shoots off to another side of your plate... Where's my hammer!  :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 28, 2013, 02:36:56 AM
Ok, I installed the noise gate add-on and whoa! No adjustment pot for the gate, just a 1M resistor... Sounds perfect to me, completely silent and no lack of anything except that damn hum! I may just wire this permanently in there and always on... Sounds perfect to me and I gotta say that sweep knob is a friggin GREAT idea!!! Makes the tone stack able to get endless ranges of tones from huge scoop to skull popping mids! Bout ready to call it a wrap with the gate! ;D You build this with the gate and you won't be sorry!!! No Hum, just blistering High Gain!  :icon_twisted:

I did make a couple changes and I will list those later.. tired :icon_neutral:

pics and sound samples to come...soon
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on February 28, 2013, 06:26:25 AM
Chin up mate  ;D
It's not working 100% and the clearcoat needs a polish, but.....

(http://i.imgur.com/Sq7RdfU.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 28, 2013, 06:40:33 AM
Chin up mate  ;D
It's not working 100% and the clearcoat needs a polish, but.....


Nice!! Not working 100%? What's wrong with it?

Looks great!  :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on February 28, 2013, 06:57:55 AM
+1 looks  :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on February 28, 2013, 08:10:46 AM
Jok3rx, you are right, I forgot there was no trimpots... I am just used to these being always there... You can try to just do the mod for the first of the mosfets since it dominates the noise figure then 10k at source and about 15k at drain, you have to change the cap too, as stated) and see if it is useful to you at least. You will loose a little gain, but it is ok.

My bad... The other tweaks still stand nonetheless

Wow... Diggin a deep hole here! Gettin worse and worse. sounds very thin and mostly just mids not to mention, for some weird reason this made the tone stack almost totally non-functional and my mid knob has now become some sort of volume knob ???

Doing this is like chasing a greasy olive around your plate with a fork trying to stab it but it escapes every time and shoots off to another side of your plate... Where's my hammer!  :icon_twisted:



Sorry man I sent you on a wrong path, I just forgot you did not use trimmers... MOSfets are actually pretty variable too (less than fets though) so I used trimmers too in the rare cases I used MOSfets, then swapped with a resistor when the ideal value was found. I don't believe in pre-canned values for anything with "fet" in the name!

I really have to breadboard that thing and try real life tweaking myself since it seems to react weirdly... There is something that does not match calculations, or even Spice simulations, just can't get my finger on it. But high non-linear behavior is not the easiest to simulate for sure.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 28, 2013, 09:04:22 AM
Jok3rx, you are right, I forgot there was no trimpots... I am just used to these being always there... You can try to just do the mod for the first of the mosfets since it dominates the noise figure then 10k at source and about 15k at drain, you have to change the cap too, as stated) and see if it is useful to you at least. You will loose a little gain, but it is ok.

My bad... The other tweaks still stand nonetheless

Wow... Diggin a deep hole here! Gettin worse and worse. sounds very thin and mostly just mids not to mention, for some weird reason this made the tone stack almost totally non-functional and my mid knob has now become some sort of volume knob ???

Doing this is like chasing a greasy olive around your plate with a fork trying to stab it but it escapes every time and shoots off to another side of your plate... Where's my hammer!  :icon_twisted:



Sorry man I sent you on a wrong path, I just forgot you did not use trimmers... MOSfets are actually pretty variable too (less than fets though) so I used trimmers too in the rare cases I used MOSfets, then swapped with a resistor when the ideal value was found. I don't believe in pre-canned values for anything with "fet" in the name!

I really have to breadboard that thing and try real life tweaking myself since it seems to react weirdly... There is something that does not match calculations, or even Spice simulations, just can't get my finger on it. But high non-linear behavior is not the easiest to simulate for sure.

That's ok man... same path I have been on. Obviously I am walking down the wrong trails into the black forest of high gain madness.... Need your help! 
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on March 01, 2013, 07:01:55 AM
Don't want to change any component because really liked the sound as per schematic but the noise is killing me.Some compromises should be made with this.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 01, 2013, 08:01:27 AM
Don't want to change any component because really liked the sound as per schematic but the noise is killing me.Some compromises should be made with this.

Have you tried that noise gate add-on yet? I have done a few changes and some other stuff... Will post this weekend
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on March 01, 2013, 05:57:03 PM
External noise gate yes(mxr v2 clone) but on slow passages i can hear the hum with the notes.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on March 02, 2013, 11:29:21 PM
Tested today hooked to F1 channel send/return without gate,the noise seems natural to me this time.Almost same noise as my stock GT2 and DT-2.F1 channel send/return colors the sound a bit(don't know if it is buffered...maybe).And as what Jok3rx advised to put a buffered pedal in front to lessen the hum.I think i'm done with this,hopefully the noise will not increase upon housing this to 1590B enclosure.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 03, 2013, 12:49:09 AM
Tested today hooked to F1 channel send/return without gate,the noise seems natural to me this time.Almost same noise as my stock GT2 and DT-2.F1 channel send/return colors the sound a bit(don't know if it is buffered...maybe).And as what Jok3rx advised to put a buffered pedal in front to lessen the hum.I think i'm done with this,hopefully the noise will not increase upon housing this to 1590B enclosure.

The F1 send / return is buffered...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on March 03, 2013, 02:25:01 AM
Thanks Jok3rx for the clarification,it's done and noise level is very tolerable without gate.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 03, 2013, 11:23:42 AM
Ok, try this... Stick a 15k resistor across the input (from input to ground) and tell me what you think :icon_biggrin: Depending on how hot your pickups are you might try between 10k and 20k, mine seems good at 15k... no noise and the vol rolls back nice and clean. Probably the same deal for the Black Forest as well...?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 03, 2013, 11:54:36 AM
I think 15k is too low for an input impedance Jok3rx!

It loads the guitar a lot!!! For sure there must be less noise than across a 1meg resistor, but it is too low for a passive pickup. There is a high-frequency roll-off that occurs then.

It may sound fine at high gain, but probably too round and muted at low gain.

I would not go under 250 - 500k.

Of course, if there is a buffer before the pedal, then this low impedance is not an issue at all.

I think that it has the merit to confirm that the noise experienced here is picked up at the first stage (picks up a lot of noise because of high impedance, but it is always a problem with passive instrument input) and amplified until becoming unbearable. Is till have to bread board that thing...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 03, 2013, 12:05:07 PM
I think 15k is too low for an input impedance Jok3rx!

It loads the guitar a lot!!! For sure there must be less noise than across a 1meg resistor, but it is too low for a passive pickup. There is a high-frequency roll-off that occurs then.

It may sound fine at high gain, but probably too round and muted at low gain.

I would not go under 250 - 500k.

Of course, if there is a buffer before the pedal, then this low impedance is not an issue at all.

I think that it has the merit to confirm that the noise experienced here is picked up at the first stage (picks up a lot of noise because of high impedance, but it is always a problem with passive instrument input) and amplified until becoming unbearable. Is till have to bread board that thing...

Nope... Not round and muted at all! Are you sure about 500k? That doesn't work...

fretz... Can you verify?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 03, 2013, 01:19:59 PM
I guess it is fine for high gain stuff since the missing high end will not be missed anyway because so much high frequency is generated in the distortion process.

If it works for you... It is just not real good to load the pickups usually, although some designs do it (a lot of fuzz pedals...). Whatever works for you at that point
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 03, 2013, 03:03:44 PM
ok, I settled at 18k from input to ground... not muffled or anything at lower volumes on the guitar, not muffled at lower gain on the pedal, no background hum with the volume off, no loss of highs (muffled), no hum at full volume etc... "NO HUM!!!" sounds perfect to me! Really sounds like 100%!!! I think I am gonna box this F#$ker up and call it a day! Really, just totally fixed it for me and I even still have the noise gate on a switch just for super silent mode... Damn, this thing sounds unbelievable!!! Also built the Hotline 2 cab simulator and WOW!!!! It's going in there too along with a tube screamer for that razor edge!  :icon_twisted:

Need to make a clean channel for a total preamp?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 03, 2013, 03:41:05 PM
jymaze - what about paralleled J201's or 2N5457's for the 1st stage? Wampler does this... less noise?

Ah well, I'll just try it and see what happens....
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on March 03, 2013, 11:17:15 PM
I'm trying to keep up with the changes still. :icon_razz:
So what did the correct value of C2 end up being?
Any resistor changes?
Is changing r24 to a trimmer an outdated fix now?
Sorry for all the questions. :icon_redface:

I tried the latest fix with 18k tacked at front end, but didn't like it with passive pickups and still hums. Maybe just give in and strong arm it with a permanent buffer at front end?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 03, 2013, 11:41:28 PM
I'm trying to keep up with the changes still. :icon_razz:
So what did the correct value of C2 end up being?
Any resistor changes?
Is changing r24 to a trimmer an outdated fix now?
Sorry for all the questions. :icon_redface:

I tried the latest fix with 18k tacked at front end, but didn't like it with passive pickups and still hums. Maybe just give in and strong arm it with a permanent buffer at front end?


Did you install the gate, yet?

18k might not work for all different pickups... experiment with different values

Quick sh!tty sample, no noise gate... How does the hotline cabsim sound?
http://dl.dropbox.com/u/11178619/New%20Preamps/ENGL_HL_CABSIM.mp3
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on March 04, 2013, 12:10:31 AM
Hey Jim - I'll hack in the gate tonight and will report back with results. I was putting off doing it in fear I would make a mess of everything and cause more problems. :icon_rolleyes:
So was 220nf the wrong value for C2?

Ah, I wanna check out your Hotline cabsim, but no sound for computer right now..... everything is tore apart waiting to recarpet the room my stereo is in, damit!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 04, 2013, 12:20:15 AM
Hey Jim - I'll hack in the gate tonight and will report back with results. I was putting off doing it in fear I would make a mess of everything and cause more problems. :icon_rolleyes:
So was 220nf the wrong value for C2?

Ah, I wanna check out your Hotline cabsim, but no sound for computer right now..... everything is tore apart waiting to recarpet the room my stereo is in, damit!!!

I will do up a diagram of all the changes I made... As for C2, not sure if I would say it was wrong at 220n but I have mine @ 47n right now and C3 is 2.2uF instead of 22uF... R8 is now 2k and R19 is 100k. C17 and C18 are 10uF surface mount tant caps. I think that's about it.. but I will go back over it and make sure.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on March 04, 2013, 02:27:13 AM
Alright, spliced in the noise gate circuit between C14 and the R19/R18 junction.
Definitely kills the high end buzz when used with active pickup, but the low end buzz is still there.... could be because I've got the circuit board wired to breadboard.
The noise gate does cause a good bit of sustain loss with gated sound unless I turn gain all the way up..

I'm gonna try the r24 trimmer thing next and then reduce the two cap values you mentioned before.
Damn, I really wanted to box this one up, so I'm hoping something will work out the buzzing without compromising the sound.... ain't quitting yet!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Maik on March 04, 2013, 09:49:23 AM
Tested today hooked to F1 channel send/return without gate,

Hey, where to find that F1 pcb?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on March 04, 2013, 07:26:57 PM
@Maik the F1 i'm talking about is original AMT pedal.Small mod to my  build R19 to 100k same as Jok3rx's.Careful with soldering because i busted one 2N7000 by changing R19 too much heat makes the V4 dead.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 04, 2013, 08:36:23 PM
Alright, spliced in the noise gate circuit between C14 and the R19/R18 junction.
Definitely kills the high end buzz when used with active pickup, but the low end buzz is still there.... could be because I've got the circuit board wired to breadboard.
The noise gate does cause a good bit of sustain loss with gated sound unless I turn gain all the way up..

I'm gonna try the r24 trimmer thing next and then reduce the two cap values you mentioned before.
Damn, I really wanted to box this one up, so I'm hoping something will work out the buzzing without compromising the sound.... ain't quitting yet!!

hmmm... Not sure man? I have mine dialed in like a dream now even with the gate at lower gain I get little to no sustain loss. But, whatever I have done has completely eliminated the noise/hum so I really don't need the gate... By the way you can adjust the gating effect by replacing the 1M resistor with a 1M/B pot so you can fine tune the gate that way. Anyway,  I tried mine with three different guitars, all with different pickups and one has EMG actives and no hum with any of them.  In any case we need to find a way to get the noise level/gain down a lot more on the 1st stage... It probably would be acceptable if we were using J201's for every stage but with those following mofets it really kicks it up in to smokin ultra high gain...

Just some thoughts I had: Lower the voltage going to the 1st stage by changing R8 to 2k. Also, maybe raise R3 to 1.8k or 2.2k or 2.7k like the Krankenstein?

These are the changes I have done to date:
Added 18k on the input to ground
Changed C2 to 47n
Changed C3 to 2.2u
Added 22pF from source to drain on V1 - J201
Changed R8 to 2k
Changed R19 to 100k
Changed C17 to 10u tantalum
Changed C18 to 10u tantalum


After thinking long and hard about this I thought, why would these Russian schematics be made this way if there is so much noise? The answer is simple, they were not, and we are not following the Russian schematics! These were originaly designed using KP303A for stage 1 and KP303E for stages 5 and 6 for a reason I am guessing. I have heard many sound samples of these preamps using the correct jfets and I can't hear any noise! So, either they are hiding the noise really really well or, we are doing something wrong or, they are simply not getting the noise in the first place. Also, from listening to their sound clips from what I can tell I think they are getting slightly less gain than what we are getting using the J201, 2N5457 or whatever! This thing produces "ultra mega gain" and therein lies the problem... These were not designed with J201's in mind! J201's are noisy as hell! Even using the lower noise 2N5457 or 2N5458 something is not right!  


This preamp has "A LOT" more gain than any of my retail AMT pedals so, I am not at all surprised that there is a lot of noise! In fact, these have too much gain which got me thinking and looking at some of the AMT schematics. Personally I consider AMT to be "THE BEST" at reproducing jfet pedal versions of these different famous preamps! One thing I noticed is that they are similar in design in that they both use some formula to scale these down rather than just copying the actual tube schematic value for value... i.e. Dr.Boogie, 7theaven, Black Forest etc... So, after looking at the AMT schematics I noticed a few things. One is that Victor K has found a great jfet in the 2SK208A-R, very good for these high gainers but very hard to get! Another thing I noticed is that he is scaling these down very precisely to produce an almost indistinguishable difference between the real thing and the pedal version! Also, I notice he does not go "over the top" with the gain which is more like the actual tube preamp and also seems to better capture/reproduce the tone! Most guitarists I know and have heard (myself included) use some sort of tube screamer variant in front of them to give them that extra bite and low end tightness! This is also commonly done with the real tube versions to overdrive the input and give the same effect.

I think we are snipe hunting here (meaning we are hunting for something magical we are not gonna find)
I just think we are going in the wrong direction and looking at the wrong things... Maybe we just need to redesign the whole 1st stage?

I noticed with these jfet/mosfet based preamps that the whole thing is scaled except for the 1 stage on all of the schematics... If you look at the Engl, VHT or Krank tube amp schematics the 1st stages are almost the same as the tube version! If you look at AMT they are totally different than the amp they are made after...

Maybe we should incorporate the AMT design or close variant into this Russian ENGL to accommodate the noisy @ss J201??? Anybody got any other ideas?

Here is the ENGL 1st stage and I am fairly sure this is correct as far as I could tell from tracing it... Should fit into this jfet/mosfet design with little or no modifications... Also take notice of the 50k gain pot.
(http://dl.dropbox.com/u/11178619/New%20Preamps/AMT%20E1%20Stage%201.png)  

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 04, 2013, 08:49:16 PM
@Maik the F1 i'm talking about is original AMT pedal.Small mod to my  build R19 to 100k same as Jok3rx's.Careful with soldering because i busted one 2N7000 by changing R19 too much heat makes the V4 dead.

Sockets!!! Use them :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on March 04, 2013, 09:21:33 PM
Hey Jim - First of all, thanks for all your patience! I'm beginning to think you are on to something by changing the 1st stage over to the 1st ENGL version and I think I may go that route.
Something weird I just noticed, but maybe I'm wrong thinking this:
On the ENGL3 drive pot, lug 1 goes to +4.5v rail per schematic and not to ground... could that be the problem?
Thanks for everything, we'll get it worked out!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 04, 2013, 10:23:25 PM
Something weird I just noticed, but maybe I'm wrong thinking this:
On the ENGL3 drive pot, lug 1 goes to +4.5v rail per schematic and not to ground... could that be the problem?

Nope... makes no difference, tried that a long time ago, ran it to ground and sounds exactly the same and the hum lives on. Nice try :icon_wink:

Might not be a bad idea - permanent buffer at front end as you stated in a earlier post... Question now is which buffer? Maybe build it on a small daughter board or piece of perf board? There is no way I can cram it into the current layout!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on March 04, 2013, 10:27:01 PM
AAAARRRGH!!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 04, 2013, 10:42:40 PM
Yep Jok3rx, too much gain... That is the diagnosis.

Basically I think this circuit has one too many stage for 9-18 volts of power supply. Think about it:

1) Real Engl/Ubershall: 4 stages  with clipping at 330+ volts

2) Pedals based on these: 4 stages with clipping at 9 volts

Incidentally the gain of one stage is probably 15-20 for a jfet and 30-40 for a MOS. SO in order to get the same clipping effect with the pedal you need about one less stage in term of gain.

Clipping 30 times earlier means 30 times worse signal-to-noise ratio or about 30 dB more noise than the same circuit built with tubes.

If I ever get around to building it (still have to find time) I may just suppress V4.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 04, 2013, 11:40:39 PM
Yep Jok3rx, too much gain... That is the diagnosis.

Basically I think this circuit has one too many stage for 9-18 volts of power supply. Think about it:

1) Real Engl/Ubershall: 4 stages  with clipping at 330+ volts

2) Pedals based on these: 4 stages with clipping at 9 volts

Incidentally the gain of one stage is probably 15-20 for a jfet and 30-40 for a MOS. SO in order to get the same clipping effect with the pedal you need about one less stage in term of gain.

Clipping 30 times earlier means 30 times worse signal-to-noise ratio or about 30 dB more noise than the same circuit built with tubes.

If I ever get around to building it (still have to find time) I may just suppress V4.

Easy enough to do... I can just jumper bypass V4 and and connect V3 to V5 and see.

Like I said earlier in this post I got this thing working like dream now... I hate tearing into this now but for the sake of all I will sacrifice... :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 04, 2013, 11:58:48 PM
Do that on your Black Forest instead!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on March 05, 2013, 12:10:14 AM
Just tested today i changed V1 to 2SK152 and biased to 4v drain and the noise goes down to normal.Loose some gain too but still sounds okay,anyway my previous V1 was 2SK117 and lots of gain where i only dial to around 2oclock.This time i can set the gain to 10.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 05, 2013, 01:17:42 AM
Do that on your Black Forest instead!

Black Forest is coming back this time with all on-board pots like Engl... all of them will be like this but hopefully without the hum from hell

Like I said before... My AMT pedals E1, P1, SS-30 and just got a B1... none of them have this much gain!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on March 05, 2013, 05:51:34 AM


jim....have you tried a 2 fet 1st stage config like the bsiab...may be quieter noise wise....just thinking aloud as the spitty is very quiet...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 05, 2013, 08:29:57 AM
Deadastronaut,

Muamp have a lot of gain (about 300) so it may be way too much gain then for the circuit unless other stages are suppressed.

To minimize noise, the best way is to maximize the gain of the first stage that has gain (if you have a quiet buffer as first stage it is ok), so it makes sense to have a first stage with a lot of gain like a mu-amp I agree.

I personally believe the best is to use an opamp where you can have huge gain and very good PSRR all at once (PSRR is horrible with cascaded jfet circuits), then after that the contribution of the rest of the circuit to the overall noise should be limited.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on March 05, 2013, 08:46:39 AM
jymaze,
So what i did is not optimal because i lessen the gain of first stage(V1).I noticed now that seems i need some more gain with this 2SK152 at V1.Maybe will try to play a bit to really used to this then evaluate again if i need to place back the K117.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 05, 2013, 09:43:30 AM
You are right. Optimally, you should lessen total gain by removing gain from the last stage at first.

The noise of cascaded gain stages is governed by the Friis formula if you want to google it. Basically the first gain stage is the most important: it should have low intrinsic noise ratio (low input noise and high PSRR) and high gain. From the second gain stage and then on, the noise contribution decreases fast, for each stage being inversely proportional to the gain of the stage immediately preceding it.

The first stage can be a buffer though, as long as it is very very quiet it does not impact the chain and the second stage is virtually a first stage in the chain then.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 05, 2013, 10:23:39 PM


jim....have you tried a 2 fet 1st stage config like the bsiab...may be quieter noise wise....just thinking aloud as the spitty is very quiet...

Rob,


I had thought about that along with a thousand other ideas that have been spinning around in my head like a sh!t tornado...

I don't necessarily know that the cause of this "HUM" is due solely to or even partially to having too much gain? Was just a guess...? Now I am leaning more towards the J201 being unsuitable for the 1st stage due to it being too noisy along with the 2N5457/58, 2SK117... Again, just a guess but from looking at the dats sheets it looks to be true? Does anybody know how these jfets compare with the Russian KP303A? I can't find a data sheet (that I can translate)...? Most people are looking at the IDSS - drain-to-source leakage current, i.e. the current that flows when the switch is off... While one jfet can have almost the same IDSS, the "noise figure versus source resistance is vastly different. J201's from what I can tell appear to be well suited until you get to looking at the noise figures! There may be other factors as well..? From what I can tell these are the best suited for these high gain jobs (2SK30ATM-R, 2SK30ATM-Y, 2SK30ATM-O / The 2SK208-R, 2SK208-Y, 2SK208-O / The 2SK879-R, 2SK879-Y, 2SK879-O) And all of the "R" class are as rare as a liberal at a NRA convention!!! These are all basically the same, not sure about the GR classification, may work also in certain areas? jymaze, correct me if I am wrong,if fretzburner was able to use the 2SK117GR then the 2SK30ATM-GR will most likely work (from what I can tell) and the noise will be very low! These are easily purchased online, I think Thai Shine/Tayda carries the Y and GR class? The BF245's look to be next in line...

jymaze, what about these?
http://www.calogic.net/pdf/SST404_Datasheet_Rev_A.pdf
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 05, 2013, 11:40:35 PM
Just found a couple 2SK30A-Y in my transistor pile that I raped from some junk radios, vcrs, TV's and everything I can find... Anyway, I tested it (had to make and adapter since different pinout but I like it! Very tube like but the HUM is still there yet ever so faint... Doesn't seem to be missing any gain either...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on March 05, 2013, 11:46:28 PM
Tried again today for V1 2SK30A-Y no more noise issue but just same gain or little more than 2SK152.As what i have tried,2SK117-GR seems ok as for gain but a little more noisy than these 2SK152 and 2SK30A-Y.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 06, 2013, 03:17:14 AM
Tried again today for V1 2SK30A-Y no more noise issue but just same gain or little more than 2SK152.As what i have tried,2SK117-GR seems ok as for gain but a little more noisy than these 2SK152 and 2SK30A-Y.

I played around with different value resistors from input to ground... tried many and 18k was the magical number for me.. didn't dampen the tone or sustain but just enough to completely kill the hum and no noise when I turn my volume pot back on my guitar. Cleans up real good too. I went back to the J201 for this just because it gives more gain than the 2sk30... not alot but I was still getting a small bit of noise on the volume roll back on the guitar... The 18k and the J201 is perfect. Also sounds killer with the simple cab sim and the hotline2 cab sim!!! Also, if I use a tube screamer in front it really kicks it in the nuts! I am going to make another one and see if I can reproduce it consistantly...

I had an idea, maybe for another preamp hybrid we could completely remove the 1st stage and replace it with a tube screamer or a SOS or SOCJ... So it would be a TS with 3 gain stages after, then a buffer, tone stack and then another buffer! I think it would sound insane since the tube screamer has a great tube like tone with great edge and no noise like the jfet stage! It sounds good with the tube screamer in front of the preamp anyway so why even mess with that noisy 1st stage anyway!? A TS sounds good on it's own so just figured it would make a good 1st stage? Maybe crazy but I am gonna try!

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: euronymous0001 on March 06, 2013, 04:29:15 AM
jok3r,

i've read from somewhere else  ;) that the BJT buffer in the TS9/TS808 input helps in keeping the noise down. maybe a bjt buffer in front of the circuit could kill some of the noise

don't take my word as if I:
1) i've tried this; and
2) i know what im saying

just suggesting from what i read.  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 06, 2013, 08:58:01 AM
Yep Jok3rx, that was my project: Build it with one less stage at the end and replace the first stage with a TS like thing (way more gain that a jfet stage). The problem is that the voicing has to be kept and it is not that easy to do for the whole gain range.

Changing the fet on the first stage should have only a minor effect on the whole gain. Not expecting more than a +/-6dB difference in gain on a total gain of 80-90 dB... Hardly anything to write home about.

I think the most important is to  choose a low noise fet, so basically NOT a J201. But as of 2N5457 versus a 2SK30, while there is certainly a difference in term of intrinsic noise, it should not produce a radical change because I still believe most of the noise is picked up by the high impedance input and from the power supply and amplified.

Why is a TS in front of it helping that much noise-wise... Still not totally sure. And that bjt buffer in the TS is not the best buffer I have ever seen... Usually I find Boss pedals noisy.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 06, 2013, 12:24:03 PM
Yep Jok3rx, that was my project: Build it with one less stage at the end and replace the first stage with a TS like thing (way more gain that a jfet stage). The problem is that the voicing has to be kept and it is not that easy to do for the whole gain range.

Changing the fet on the first stage should have only a minor effect on the whole gain. Not expecting more than a +/-6dB difference in gain on a total gain of 80-90 dB... Hardly anything to write home about.

I think the most important is to  choose a low noise fet, so basically NOT a J201. But as of 2N5457 versus a 2SK30, while there is certainly a difference in term of intrinsic noise, it should not produce a radical change because I still believe most of the noise is picked up by the high impedance input and from the power supply and amplified.

Why is a TS in front of it helping that much noise-wise... Still not totally sure. And that bjt buffer in the TS is not the best buffer I have ever seen... Usually I find Boss pedals noisy.

Like I said, the way I have mine now it's noise free but I am not really comfortable with the resistor across the input to ground! I think it will change from guitar to guitar.. My 3 guitars are pretty evenly matched as far as output/pickups etc.. I hate to alter the circuit too much because I love the tone and the gain it produces! I think the best way to go is a hardwired/permanent buffer (not sure which would be the most effective and transparent?) in front of preamp! Put it on a small vero or perf board for now... I will make a layout as soon as I decide on what is the best one (any ideas besides the TS buffer?) If we start changing the circuit it seems like it creates a chain reaction of other issues that are never ending... So far nothing has squashed the HUM to my satisfaction! Yes, mine works perfectly with my guitars but who knows what it will do with other guitars?  

Solutions:
1. Add permanant buffer in front of the input. I can easily redraw the layout to accommodate this, may be a slight bit deeper but can be done! What about an opamp buffer?
2. Build pedal with on-board tube screamer or variant - When tube screamer is on will act as "lead channel" extra tight, edge etc. / When off will just utilize the TS buffer. If you want "true bypass" either use an A/B switch to completely bypass the pedal or put a second stomp switch in the pedal that bypasses both the TS and the preamp. Not hard to do! Plus the way that the preamp is laid out gives plenty of room inside the enclosure for other stuff unless you are one of those people who likes to jam everything into an enclosure the size of a lipstick case for whatever reason unknown to me? Small is Not a good idea for high gain circuits in my opinion anyway ...

jymaze - I bypassed the 4th gain stage/mosfet and didn't sound good at all! Sounded like it got neutered (lost it's balls)  :icon_cry:

By the way - I built the other Russian preamps/pedals that don't use mosfets like the Uber, Bogner XTC and Soldano, all jfet/J201 and none of them have any noise what so ever but non of them have the beastly gain that the mosfet designs have either so go figure :icon_rolleyes: Actually, they don't even come close and absolutely require the aid of a tube screamer to get anywhere near the mosfet killers! They are more along the lines of the Dr.Boogie, maybe a little less gain...  
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 06, 2013, 01:40:24 PM
I agree, it is always a dilemma: The balls of over-the-top gain versus the uncontrollable noise.

Anecdote:
 I have a Line 6 amp and it sounds okay for what it is, I use it once in a while. So last week I plug it in and put it on high gain and it just sounds much more exciting and ballsy than usual, but with weird background noise. Then I check my pedal board and I was running my Riot clone with gain at 3 o' clock into it. So yes, over the top gain gives balls, but it gets noisy...

So suppressing V4 sounds neutered... but at least did it lower the noise to positively? Also, neutered compared to the original would still be ok for other folks, if a Dr Boogie sounds neutered to you, then dropping V4 on this one may not be that bad in all respect...

You can book end the whole thing between a double opamp buffer I guess (you can even suppress V6 then). Opamps are the best transparent buffers from an electronic point of view, much better than a lone bjt.

What settings do you use on your TS by curiosity? Do you use it more for the gain or the eq?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 06, 2013, 02:21:57 PM
What settings do you use on your TS by curiosity? Do you use it more for the gain or the eq?

Well I use it a couple of ways just depends on my ears...

1. I use it for very slight edge, not really gain so much - Gain on 0 or 1 / Tone on 5 or half way / Level on 2 or 3, just cracked enough to let the full guitar signal come through. This gives it a tight edge on the lows and a slight bit more sustain.

2. I turn the gain down on the preamp to about 5 - Then on the TS I set the Gain on about 3 / The Tone the same as before / The Level on about 5 or 6. This does about the same thing but give you a slightly different bite and attack.

Note: When I say for example Gain on 5 or Level on 3 I am referring to the actual rotation level of the pots, NOT the o'clock position...

I could do without a tone knob all together as I very rarely even move mine, always stays in the middle or a bit less.

I don't use the tube screamer like a lot of others do like say run it into a clean or slightly dirty amp and use the higher settings on the tube screamer to get my overdrive sound... I just use it for slight edge, that's it! The Engl hardly even needs it but others like the Dr.Boogie etc. kinda need the help... Not knocking the Boogie at all, it's a great pedal! Most (a lot) of people use it as a distortion box and run it into the front input of their amp, that gives it a lot more balls but if you run it straight into a PC or power amp it's a different story all together... I don't like using it as a distortion box. If I am gonna do that I will use a Riot or Crunch Box or something like that into the front of an amp! I'm not really a person that likes to run a "preamp" into another preamp... But hey, if it sounds good, then it is good! :icon_wink:

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on March 06, 2013, 05:40:12 PM
First time used this preamp direct to subway rocket return input and sounds huge.compared it to amp alone way more gain than the crunch channel,while with the contour channel same gain but the boogie sounds more bass.Both of them have natural(acceptable) noise with guitar volume full and same noise level between this preamp and the boogie amp alone.So I think my quest to lower the noise level is over now.And i did not use a buffer at preamp input.Changes made to the circuit is just the 33k to 100k resistor R19,some supply filter caps and the first stage 2SK30A-Y.
Like Jok3rx said i don't want to heavily alter the circuit because stock from schematic this preamp sounds very very good except that noise.
Note:when i say preamp i'm referring it to this engl build.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: euronymous0001 on March 08, 2013, 08:16:29 AM
hey jok3r, have you tried using BS170 instead of 2N7000?  :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluebunny on March 08, 2013, 10:30:32 AM
hey jok3r, have you tried using BS170 instead of 2N7000?  :icon_mrgreen:

As I understand, they are pretty much interchangeable.  Careful with orientation: they "face" in opposite directions.  Anything to add from your experience, Jim?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: euronymous0001 on March 08, 2013, 10:53:55 AM
hey jok3r, have you tried using BS170 instead of 2N7000?  :icon_mrgreen:

As I understand, they are pretty much interchangeable.  Careful with orientation: they "face" in opposite directions.  Anything to add from your experience, Jim?


soulsonic, AFAIK, stated that the BS170 where "smoother" than the 2N7000 which where "grittier". I'm NOT sure if this will solve the problem because it was not said that it WAS MORE QUIET.   :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 08, 2013, 07:48:53 PM
hey jok3r, have you tried using BS170 instead of 2N7000?  :icon_mrgreen:

As I understand, they are pretty much interchangeable.  Careful with orientation: they "face" in opposite directions.  Anything to add from your experience, Jim?

Tried the BS170's.. 1 - They make no difference in the noise factor here, still noisy. 2 - They are a slight bit rounder/warmer sounding, maybe a good thing, maybe not... depends on what you like. I like the 2n7000 more because they sound plenty warm and seem to give it an extra bit of edge. Also, I like them because they are CHEEEP! I can get like 50 2n7000's for the price of 5 BS170's. Don't get me wrong, if the BS170's made an improvement in the tone, attack, gain, "NOISE" and over all better sound I would not hesitate for a moment to buy/use them over the 2n7000's but, I actually think the 7000's sound better!  

Ok, Here is "MY" fix for the HUM/NOISE... This works!!! As I said a couple pages back if I stick a retail tube screamer (mine is the TS7 with the TS808 mod) with buffered bypass (not true bypass) in front of the Engl preamp pedal it kills the noise and the guitar volume knob roll back noise increase problem 100%!!! That is just with the TS in bypass mode. There is no gain loss, no tone loss, no sustain loss just kills the noise 100%! The only noise left is pure high gain and normal noise associated with high gain, a little bit of noise is to be expected but it's very minimal considering the gain this thing puts out!! There is a distinct difference between "normal noise" and this constant over riding low level hum that consumes the sound! It's like there is another guitar cord unplugged laying on the ground buzzzing in the background. Anyway, the buffer in this TS7 completely cures this 100%.

Now, I have built a TS input buffer and it didn't work,meaning it didn't fix the hum sound like my TS7...
I used this buffer, pretty common... 2nd diagram.. I tried a 2n5088 and a 2n3904
http://www.muzique.com/lab/tsbuff.htm  

Must not be the same as the TS7 buffer? Anyway, if you look up the schematics for the TS7 you get different buffers with different schematics etc.. Looks like the "real" schematic is using two 2SC1815's for the input/bypass buffer? Or, am I reading this thing wrong? Sorry, can't find the link for it but I have the pdf... Whatever the TS7 is using is the ticket to a 100% bug free working preamp!!!

Edit: still can't find the original pdf to the TS7 but found this and has some cut outs from the schematic, one has the input buffer...
http://www.marksmart.net/gearhack/ts7/carboncomp/carboncomp.html
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on March 08, 2013, 09:53:55 PM
About the TS buffer circuit:
I wonder if you would use that 510k resistor that's connected to +4.5v or omit ?
EDIT:
Nevermind.... what a stupid f&%^$# question!!


Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 09, 2013, 01:01:52 AM
This buffer thing is really weird for sure Jok3rx. It is like anything in the same enclosure as the preamp is doomed with noise.

When you put your TS7 before the Engl MOSfet on your board, they both share the same power supply?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 09, 2013, 01:51:24 AM
When you put your TS7 before the Engl MOSfet on your board, they both share the same power supply?

Sure do.. yup!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on March 10, 2013, 02:45:46 PM
@ jim: It sounds killer!  :icon_twisted: :icon_twisted: :icon_twisted:

ok, as promised:
http://dl.dropbox.com/u/3511352/Black%20Forest_1590B%20layout_gate%20version.pdf (http://dl.dropbox.com/u/3511352/Black%20Forest_1590B%20layout_gate%20version.pdf)-------> UNVERIFIED

should be ok  ;) please report errors or tell me if you need explanations. Enjoy  :)

Ciao :)




I'm back..finally.. Sorry to report to have a not working black forest :icon_cry: :icon_cry: Seems that my layout has a mistake.
I'll repost when correct
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 11, 2013, 12:39:15 AM
@ jim: It sounds killer!  :icon_twisted: :icon_twisted: :icon_twisted:

ok, as promised:
http://dl.dropbox.com/u/3511352/Black%20Forest_1590B%20layout_gate%20version.pdf (http://dl.dropbox.com/u/3511352/Black%20Forest_1590B%20layout_gate%20version.pdf)-------> UNVERIFIED

should be ok  ;) please report errors or tell me if you need explanations. Enjoy  :)

Ciao :)




I'm back..finally.. Sorry to report to have a not working black forest :icon_cry: :icon_cry: Seems that my layout has a mistake.
I'll repost when correct

Here ya go, sorry it didn't work... Probe around and check your voltages may give you a clue? Probably a small re-rout of a trace or something easy to fix...So, I wouldn't scrap the one you etched just yet.
http://dl.dropbox.com/u/11178619/New%20Preamps/black_forest_v3.1.PNG

There is probably a few parts you can leave out like C11 and the noise gate etc... It needs an input buffer like the Engl I think? That will be on a small daughter board once I figure it out.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: ggedamed on March 11, 2013, 10:29:15 AM
Hi guys, i'm here to report having a russian/JokerX Engl on my breadboard. It definitely has the growl. And the noise ;D. Still, my preference goes with the all-JFET-AMT-style circuits. The Engl on my breadboard seems heavy filtered and kinda uni-dimensional. It reminds me a bit about Sansamp GT2 - gorgeous sounds, but not big variation with the position of the knobs, the type of guitar/pickups or the technique (not that I would know anything about guitar technique  :icon_lol:).
Granted, all of these could be errors on my part.
I put some doodling on Souncloud (http://snd.sc/ZtTG0j), so if you have any suggestions, I'm all ears. I know that I should tune my guitar and I should practice more, so you can skip that part :D. I also definitely favor highs, it could be my age. BTW, GZB 7.3.4 (in a Sound JS OD5 box) (http://snd.sc/ZtWDOn) is an all-JFET-AMT-style distortion, so you can compare between my results.
My native language is not English, so be gentle with the slip-ups.

LATER EDIT: I mistakenly started with a cabsim attached to the end of the Engl mod, not knowing that it sounds better without it. So, if you want to skip the cabsim part, go to 2:15.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 11, 2013, 12:40:30 PM
Thanks for the sound sample ggedamed.

What is that GZB thing? I could not find anything... Is there a schematic? It sounds pretty good to me actually.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on March 11, 2013, 01:34:05 PM
Thanks in advance Jim. Some voltages...time to double check connections and to audio-probe

Black Forest voltages
Q1
D:4,54
S:0,3
G:0
----------------
Q2
D:4,51
S:0,25
G:0
----------------
Q3
D:4,5
S:0,48
G:0
----------------
Q4
D:4,53
S:0,35
G:0
----------------
Q5
D:4,5
S:0,39
G:0
----------------
Q6
D:8,94
S:4,6
G:4,48
----------------


Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: ggedamed on March 11, 2013, 03:59:32 PM
Heh! GZB is an acronym for "Gingi Za Best" which means something like "Chuga-Chuga The Best". Regional joke. I use it to refer to all distortions I ever made.
This one is my interpretation of the AMT L1 series. I intend to say the full story ot its creation (on the both forums, no less  :icon_biggrin:), only it takes time to gather all the facts and here it is off-topic anyway.
Right now I can tell you that it is the generic tube amp-inspired/Dr. Boogie self-biased common source JFET amplifiers chain, including the AMT BAT85 diodes between gate and source. There are 5 transistors in the distortion part, the first one and the post-TS buffer are 2SK30s, the second stage is 2SK117, the third stage (pre-TS) 2SK117 buffered by another 2SK117. I like 2SK117 because of the higher gain + lower noise compared to pretty much every other JFET.
In case you're interested, the cabsim is also from AMT (http://www.amtelectronics.com/support/articles/the_guitar_speaker_simulator_by_victor_kempf/).
Oh, and having some MAX1044 received as samples from the good guys at Maxim I supplied the distortion part with ~25V and the cabsim with ~17V.
Just pure, clean fun.

Sorry, Jim, I'm stopping the off-topic-ness right now :D.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 11, 2013, 07:09:25 PM
Heh! GZB is an acronym for "Gingi Za Best" which means something like "Chuga-Chuga The Best". Regional joke. I use it to refer to all distortions I ever made.
This one is my interpretation of the AMT L1 series. I intend to say the full story ot its creation (on the both forums, no less  :icon_biggrin:), only it takes time to gather all the facts and here it is off-topic anyway.
Right now I can tell you that it is the generic tube amp-inspired/Dr. Boogie self-biased common source JFET amplifiers chain, including the AMT BAT85 diodes between gate and source. There are 5 transistors in the distortion part, the first one and the post-TS buffer are 2SK30s, the second stage is 2SK117, the third stage (pre-TS) 2SK117 buffered by another 2SK117. I like 2SK117 because of the higher gain + lower noise compared to pretty much every other JFET.
In case you're interested, the cabsim is also from AMT (http://www.amtelectronics.com/support/articles/the_guitar_speaker_simulator_by_victor_kempf/).
Oh, and having some MAX1044 received as samples from the good guys at Maxim I supplied the distortion part with ~25V and the cabsim with ~17V.
Just pure, clean fun.

Sorry, Jim, I'm stopping the off-topic-ness right now :D.


Dude, don't stop!!! Bring it bro :icon_wink: Anything high gain is welcome by me any day!! High gain is the topic as far as I am concerned so it's not off-topic! I am very interested in what you have created!  I spent some time messing with the AMT Legend stuff, all very cool and some of the best around in my opinion...! I also use bat54 SMD diodes between gate and source on the all jfet based preamps, never got around to changing it on the older schematics...

I know people are probably getting discouraged by this never ending thread that is jumping from one pedal to another but the way I look at it is at least it's all in one place...

Don't feel like you gotta post under this thread but you can if you want, I don't care! I just wanna see some schematics, layouts etc.. and the cab sim too! I am very happy with the Hotline 2 and the SCS (both Russian/Ukrainian) cab sims right now but always looking for others...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 11, 2013, 10:48:34 PM
I am with Jok3rx: Want to see that GZB!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on March 12, 2013, 04:49:21 AM
+1 too... :icon_twisted:

keep em coming..\m/  :icon_twisted:  \m/
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: ggedamed on March 12, 2013, 03:11:53 PM
OK, guys. Thanks for your interest.
I promise I'll make a thread dedicated to the whole process. I found some interesting facts on this journey and it's gotta be presented right. My spare time is quite sparse, that's why it's not yet ready.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 12, 2013, 07:05:02 PM
OK, guys. Thanks for your interest.
I promise I'll make a thread dedicated to the whole process. I found some interesting facts on this journey and it's gotta be presented right. My spare time is quite sparse, that's why it's not yet ready.

 :icon_rolleyes: Oh sure, give us all boners with talk of yer cool pedals then make us all wait... nice  :icon_lol:

Are you talking about the "original AMT pedals" and biasing jfets using something like a BC547 NPN transistor with a bav21 diode or the like between gate and drain? I know that's kinda vague but I have seen this done...


Edit: ok nevermind what I attempted to say.. here's a pic.
(http://dl.dropbox.com/u/11178619/Self%20bias.png)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 13, 2013, 01:12:56 AM
Ok, I think I found the fix for "THE HUM" :icon_mrgreen:

Here is what I did and I get ZERO hum! This is what I did just messing around so there is probably a neater way...

1.) Added a 500Ω resistor right on the +9V power on the jack to the +9V input on the board. You may be able to use a lower value.. this is just what I grabbed and it worked so it'sa stayin on there! I thought I would start with 500Ω and work my way down if needed but, 500Ω seems fine...
2.) Added a 100uF cap right on the power jack between the +9V and ground. Maybe 220uF will work better? Make sure polarity is right, of course!  :o
3.) This is the kicker! All "separate shielded wires" for everything going to and coming from the board and, it matters where the wires are routed preferably not over the top of the board... No noise, for real!!

I also biased the first jfet (J201) and then removed the trim pot, measured it with my meter and replaced it with a fixed resistor of the same value... The trim pot is noisy as hell by the way, and I used a good one!

If you do all this and still get noise then move the jacks away from the board, mine don't like to be any closer than about 2 inches from the board...

Everything else is stock values just like the schematic. I did add 22pF caps between the gate and drain of V2 and V4 but I don't know that this did anything for the noise but it did make it a little less harsh, more tube like sounding, I think.

Note: This circuit is EXTREMELY susceptible to interference form it's own connectors and any external stuff!!!

Ok now, DO IT!  :icon_lol: By the way, this doesn't effect the gain or sustain in any way!! And no need for the noise gate! :icon_lol:

Somebody that built this Engl please verify! I want others besides me to say it works :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Somicide on March 13, 2013, 04:23:19 AM
after the SMD thread, I'm thinking I may have to get brave (and a new Rx for glasses) and try it super-tiny.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 13, 2013, 07:15:05 AM
I'll build one and try it out Joker. :) Already built the black forest (with gate on perfboard) and liked it, got it set up in an enclosure together with a PT2399 delay and a AMZ booster. It's the only pedal i use nowadays, a bit battery hungry though with all 3 sharing the same battery.

Just gonna wait until i get rid of my fever/headache and try the Engl out, been following the thread for quite a while.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 13, 2013, 10:49:19 AM
So I was shielding problems... Glad you found the cure. I am sure filtering the power supply helped too.

Somehow I never had to shield any wires in my builds, the shielding of the enclosure was always enough (I also ground the casings of all my pots). Not sure I ever had something with as much gain tough.

It still does not really explain why a tube screamer in front solves the noise problem... Whatever...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 13, 2013, 11:13:59 AM
Built a couple of high gain circuits, the DR. Boogey for example, i had some oscillating issues which a buffer resolved aswell. can we just call buffers Magic? ;)

Instrumental song i recorded using the black forest, my delay and my new 7-string (ESP LTD MH-417), alot of the stuff in the song is improvised and quite sloppy, but should give an idea how i made it sound. quite heavily mid scooped and run through guitar rig.
https://soundcloud.com/#stormbringer79/instrumental (https://soundcloud.com/#stormbringer79/instrumental)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 13, 2013, 11:50:02 AM
Built a couple of high gain circuits, the DR. Boogey for example, i had some oscillating issues which a buffer resolved aswell. can we just call buffers Magic? ;)

Instrumental song i recorded using the black forest, my delay and my new 7-string (ESP LTD MH-417), alot of the stuff in the song is improvised and quite sloppy, but should give an idea how i made it sound. quite heavily mid scooped and run through guitar rig.
https://soundcloud.com/#stormbringer79/instrumental (https://soundcloud.com/#stormbringer79/instrumental)

That sounds FANTASTIC!!! \m/ :icon_twisted:\m/

Those harmonies sound great man!!! And, those squeal pinch harmonics are wicked! I thought it was a metal version of the Halloween movie theme song at first the way it starts out...  :icon_twisted:

jymaze - I never really had to shield any wires in my builds either with the AMT clone stuff and Dr.Boogie etc... These are different, obviously! And the tube screamer buffer is puzzling to me also but like stormbringer said, buffer magic...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 13, 2013, 12:18:58 PM
Thanx :)

Gonna start building the ENGL 3 with your fixes on perfboard here now. But with off-board pots (out of PCB mount pots, but will keep the leads short) and see what it sounds like. Will try it with both my old guitar (unbuffered passive EMG's), and the new 7-string with active EMG's.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 13, 2013, 12:49:52 PM
Thanx :)

Gonna start building the ENGL 3 with your fixes on perfboard here now. But with off-board pots (out of PCB mount pots, but will keep the leads short) and see what it sounds like. Will try it with both my old guitar (unbuffered passive EMG's), and the new 7-string with active EMG's.

Kool! The only pot that gets noise is really just the gain pot so be aware of that...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 13, 2013, 12:53:45 PM
Stormbringer,

It sounds awesome! you are quite the player. If you think it is sloppy, I would like to be just half sloppy as your are on these 32nd notes (or whatever they are).
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on March 13, 2013, 01:55:04 PM
@stormbringer:   \m/   :icon_twisted:  \m/  ....sounds great man. excellent.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 13, 2013, 04:25:33 PM
@stormbringer:   \m/   :icon_twisted:  \m/  ....sounds great man. excellent.

c'mon Rob, you know you wanna make one of these and join the "NO HUM CLUB" formerly the "MO HUM CLUB" :icon_twisted:

Also would be nice to have somebody with your knowledge messing with it first hand!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 13, 2013, 04:38:31 PM
after the SMD thread, I'm thinking I may have to get brave (and a new Rx for glasses) and try it super-tiny.

Do it... I ain't afraid of no SMD! Actually I prefer surface mount over through hole, just been lazy and already have a crap ton of through hole parts... I am quite comfortable with SMT since I did work as a SMT rework tech for years and probably have done well over tens of thousands of boards in production... Really small fine pitch stuff too and BGA's etc... The fear factor of soldering SMD has no hold on me what so ever!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 13, 2013, 06:40:56 PM
Alright. Built the ENGL, Can't bias properly at the moment though, due to a faulty trim pot.
Need to order a couple of new ones. Will check back in a couple of days when i get them delivered and get it all working. :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 13, 2013, 06:52:49 PM
Alright. Built the ENGL, Can't bias properly at the moment though, due to a faulty trim pot.
Need to order a couple of new ones. Will check back in a couple of days when i get them delivered and get it all working. :)

Damn! So close, yet so far away... :icon_sad:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 14, 2013, 01:44:47 PM
Alright, managed to find a 100k Trimpot, so got it up and running with that. Just gonna fine tune it now and replace with a resistor, and also see how it sounds with a 808 in front. :) i like it so far. Good work! Although i prefer the sound i get from black forest for chugging parts, the lead sound with this is superior. Gonna have some fun with this after dinner. :D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 14, 2013, 02:50:37 PM
Quick and dirty recording with the ENGL, as usual i improvised and didnt learn the stuff i recorded properly before playing ^^ sloppy again. Not really the punch my last recording had due to no bass or drums. but anyway. here's a short audio clip. :)

https://soundcloud.com/stormbringer79/engltest (http://soundcloud.com/#stormbringer79/engltest)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 14, 2013, 07:12:00 PM
Alright, managed to find a 100k Trimpot, so got it up and running with that. Just gonna fine tune it now and replace with a resistor, and also see how it sounds with a 808 in front. :) i like it so far. Good work! Although i prefer the sound i get from black forest for chugging parts, the lead sound with this is superior. Gonna have some fun with this after dinner. :D

Ok, your clip sounds great, again!! I agree about the fat low end of the Black Forest as compared to the Engl. I thought the same thing also the BF has a very wide low end and you can get some real good harmonics, squeal notes etc... The Engl has a great lead tone and is really easy to do fast smooth runs with, maybe not as stiff feeling as the BF and a lot of mid range, does really well with the neck pickup as well! I think some tweaking with the tone stack would give a broader wider sound like the BF... Both have a very tight low end attack but I think the Engl is a little tighter, if that's even possible! Great for 7 and 8 string!!

So I gotta ask, how is the noise/hum factor??? The noise/hum is the only thing holding me back on both the BF and the Engl... Do you get a surge of noise when you roll the vol pot back on your guitar etc.. What did you do, not do etc...

Edit: I thought I was fast at throwin things together but I think you got me beat!

~ Jim
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 14, 2013, 07:25:54 PM
Yeah, i agree. :) I could probably get a little heavier tone from it aswell when i get to experiment more and get more familiar with the tonestack.

I actually decided to build it Stock first to help finding where the hum comes from (although gain pot wires, input and output are shielded), i do get some hum, lower after i replaced the trim pot with a resistor though. but it's still present with my homebuilt OD808. I will check your solutions out one at a time and see where it stops.

I do build quite fast when theres a pcb layout to work with (although i use the perfboard and bending legs from components to match pcb pattern approach), but i've had this project in mind for a while, so i had already bought the parts needed. :)

edit: oh, right. i forgot. Rollback volume works well, although. at lowest gain pot-setting i get oscillation. only at the lowest 1-2 % though. High pitch sqeal, but might be my home-made traces being to wide and close to eachother somewhere.

edit 2: (getting late, sorry). The black forest i built was with the noise gate addon. it's absolutely silent using my 7-string with volume down, had a small amount of hum with my passive mic 6-string. but i can barely hear a difference when i switch the pedal on with strings muted while running it quite loud through my randall RH100 when rehearsing with my band.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on March 15, 2013, 12:40:44 AM
What you guys mean with volume down? Not same as volume off?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 15, 2013, 01:12:19 AM
What you guys mean with volume down? Not same as volume off?

Volume on the guitar... When I turn my volume down on my guitar the noise increases until all the way down and you can still hear the hum... Slowly getting rid of the hum. I thought I had gotten rid of it yesterday with the simple things I explained some posts back but, then I plugged in today and I hear the F@$#king hum again.. not too bad at all but WTF!!! I want it GONE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!  

I am getting tired of this sh!t, been chasing this humming ghost for months now!!!! First the Black F&*King Forest and now the ENGL!!! WTFF???? Can you tell I AM PISSED OFF?  :icon_twisted: :icon_twisted: :icon_twisted: :icon_twisted: :icon_twisted: :icon_twisted: :icon_twisted:

And I am not gonna settle for this is "TOO MUCH GAIN" cause that's Bull ShiZZy!!! This has a lot of gain but c'mon, really? It doesn't have too much gain cause when I hook up my TS pedal it has even more gain and the noise goes away???? It's the front end of this thing... It's hummin like a F$&kin geiger counter sittin on top of a box of spent reactor rods!!! Bull Sh!t!!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 15, 2013, 01:35:31 AM
Bout ready to issue a ***REWARD*** to anybody who can get me out of this HUMMMMMMMING HELL that I am living in!!!! Find a "LEGIT FIX" for this problem and I will send you a damn near brand new AMT P1 pedal in the box, no scratches and never had a foot touch it, and it DOESN'T HUM...! Who's up for it? The fix has to be a legit fix! Can't effect the tone or the gain and has to retain the "bad@assness" of the pedal minus the HUM! This is not a contest, it's a gift!

If you live in some far off land like Zimbabwe, outer Mongolia or Timbuktu then forget it!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 15, 2013, 02:51:54 AM
I'm far off (sweden), but i wanna change the reward to atleast 30 more pages of this thread if i find the problem. ;)

Going away for a couple of days right now though, but will start experimenting when i get home again.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on March 15, 2013, 06:01:58 AM
CALM DOWN JIM!!!!!!!!...... deep breaths, ..........deep..................deep.................................breathe slowly......in................................out............................in.........................in.................in..................in.................BANG!!!!!... ;D

I understand the frustration of  getting 'nearly there' with home grown stuff!...been there, and will be again no doubt. :)

I'm pretty sure if you started a thread with that  offer ( with full schemo  and ask that answers be directed/ linked to this thread of course (put a link to here ).

that some of the more knowledgable EE guys would jump on it ....everyone loves a freebie right!......plus everyone gets a fully working schemo....WIN WIN... :icon_cool:

btw i live in the congo  :P




Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 15, 2013, 09:44:07 AM
Probably a good answer would be to use double side PCB with a ground plane, neat ribbon connectors that prevent random cross-talk, and perfect grounding of the enclosure. I am pretty sure it is one of the factors explaining why the AMT pedals do not hum...

It is just harder for a DIYer to get to that level of engineering.

Maybe I am just asking again and again, but how would you describe your hum? Is it like 60-120Hz hum? Is it more like white noise? Is it high pitched? I think I remember you also saying it hums with no input chord plugged in, but I am not sure. We just have to knock down every possible source of noise one by one. Do you still have your 18k grounding resistor at the input?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: defaced on March 15, 2013, 09:51:44 AM
Bout ready to issue a ***REWARD*** to anybody who can get me out of this HUMMMMMMMING HELL that I am living in!!!! Find a "LEGIT FIX" for this problem and I will send you a damn near brand new AMT P1 pedal in the box, no scratches and never had a foot touch it, and it DOESN'T HUM...! Who's up for it? The fix has to be a legit fix! Can't effect the tone or the gain and has to retain the "bad@assness" of the pedal minus the HUM! This is not a contest, it's a gift!

If you live in some far off land like Zimbabwe, outer Mongolia or Timbuktu then forget it!
If you etch a board, I'll buy it from you and build it.  High gain tube amps are my thing.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: caspercody on March 15, 2013, 09:56:08 AM
I am not sure what you are using for a power supply, but if you are using a wall wart power supply do you have any filters? I think it was on the "Tube boost + overdrive running off a 9 volt battery" that they were talking about adding some caps, and a voltage regulator to a wall wart to get rid of noise. Scroll down to page 8 on this:

http://www.aronnelson.com/DIYFiles/up/12AU7-6111_Valve_Caster_Summary_Rev002.pdf

Hope some of this helps.

Rob
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: caspercody on March 15, 2013, 10:01:36 AM
Forgot one more thing,,, I read somewhere to put a 100 ohm resistor in after the + voltage connection and before the circuit. Also to put a large cap (470uf) from + to ground, and also a 100nf cap. I think you might have tried this already...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 15, 2013, 11:17:16 AM
I think Jok3rx reported noise under 9v battery operation, must not be a dirty power supply then...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 15, 2013, 12:03:18 PM
Tried it with a new 9v battery and still get the noise... I have a 1Spot power adapter and it must be regulated because it reads a solid steady 9.5v all the time load or no load. I power my other pedals with it (Dr.Boogie, AMT, AMT clones etc) and have no problems, at all. And no, I do not run them all daisy chained... just maybe a TS808 into the preamp pedal straight into whatever, amp, recording interface etc.. I do not run any other pedals nor do I like any other pedals before my preamp, no delays, no chorus, reverb etc... I prefer to add these either after the preamp or not at all and just add them to the recording using VST pluggins... But for the most part I do not like any pedals before or after the preamp with the exception of a tube screamer before the preamp and sometimes I don't even use that depending on what volume I am running at or whether or not the preamp needs a little kick in the ass...

The hum or buzz is a low level, low pitch noise, not high pitched and not what I would call white noise or hiss. You can get an idea of what it sounds like simply by taking your guitar cord coming from your amp out of the jack on the guitar and just put your thumb on the tip of the cord and leave it there. This noise is always present in the background and doesn't seem to be effected by the actual guitar signal nor does it really interfere with the actual guitar signal, just kind of rides along side it or behind it. It seems to almost disappear with the volume all the way up on the guitar but if you turn the volume knob on the guitar back to say around 75% it intensifies and continues to intensify the lower you turn the volume knob to the point where the noise becomes just as loud as the guitar signal and this happens at around 50% volume. If you mute the strings with the guitar on full volume you can hear it but it's not nearly as bad and almost doesn't even exist at that point, but I can hear it, still! Just mainly when you turn the vol pot on the guitar back it surges or builds to a very loud level to where it finally overtakes the guitar signal and from there the lower you go the louder it gets until you have the volume all the way off and then there is no sound except you can still kinda hear the faint hum in your speakers.  

The other day it appeared that I had fixed it and it seemed to be working perfectly!! Then, I unplugged it and put it in the cabinet, came back the next day, plugged it all back in and...... HUMMMMMMMMM :icon_evil: :'( :icon_evil: :'( :icon_evil: :'(  

I removed the 18k resistor from input to ground. It cures the hum 100% but it also cuts/dampens the signal to a certain degree and there is some gain loss. The noise gate gets rid of 85% of the hum but still some bleeds through, I like it better since you can adjust it with a 1k pot and it is actually I nice feature hum or no hum.. If you are running at very high volumes you are gonna get all kinds of rogue noise and feedback so the gate is a cool feature in my opinion.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 15, 2013, 12:30:15 PM
CALM DOWN JIM!!!!!!!!...... deep breaths, ..........deep..................deep.................................breathe slowly......in................................out............................in.........................in.................in..................in.................BANG!!!!!... ;D

I understand the frustration of  getting 'nearly there' with home grown stuff!...been there, and will be again no doubt. :)

I'm pretty sure if you started a thread with that  offer ( with full schemo  and ask that answers be directed/ linked to this thread of course (put a link to here ).

that some of the more knowledgable EE guys would jump on it ....everyone loves a freebie right!......plus everyone gets a fully working schemo....WIN WIN... :icon_cool:


btw i live in the congo  :P

Rob,

Actually, that was kinda calming until I got to the BANG!!!!!! and then I was double pissed cause it tricked me :icon_mrgreen:

Good idea... I didn't want to start a "unauthorized contest" in here and get into trouble! But, yeah I could do that!

Congo UK? I think they do air drops over that area to the native tribes and savages? I could ship the pedal in with some supplies but if the Silverbacks get hold of it I am not responsible... You might have to dig your prize out of a steaming pile of gorilla sh!t if that's ok?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: ggedamed on March 15, 2013, 01:02:44 PM
Jim, two questions:
1. Do you have nearby a fluorescent light or some kind of electric engine? I also had  anger management issues until I discovered that my problem was on the desk - a fluorescent lamp that was bought recently.
2. If a Tube Screamer solves your problem, why don't you use a buffered bypass? I wanted to house a pedal in an old pedal case Boss-size and there were lots of wires inside  - I couldn't tame the oscillation that appeared beyond a certain gain level until I put an op amp buffer inside. I lost the true-bypass thingie, but I gained a really nice buffer.

Also, why don't you record the damn noise? A recording is worth 10000 words.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 15, 2013, 01:14:35 PM
Jim, two questions:
1. Do you have nearby a fluorescent light or some kind of electric engine? I also had  anger management issues until I discovered that my problem was on the desk - a fluorescent lamp that was bought recently.
2. If a Tube Screamer solves your problem, why don't you use a buffered bypass? I wanted to house a pedal in an old pedal case Boss-size and there were lots of wires inside  - I couldn't tame the oscillation that appeared beyond a certain gain level until I put an op amp buffer inside. I lost the true-bypass thingie, but I gained a really nice buffer.

Also, why don't you record the damn noise? A recording is worth 10000 words.

Ok here's the damn noise... around :59 I switch on the DIY tube screamer (has true bypass) so I have the TS on very low settings but you can still hear how the hum is almost if not all gone.. Then later on I switch the TS back off (you can hear the click) and you can hear the hum again. Also I roll my vol pot on the guitar up and down a few times in the recording so you can hear the hum fade in and out.

http://dl.dropbox.com/u/11178619/New%20Preamps/ENGL_HUM.mp3

No motors, no fluorescent lighting, no electric tooth brushes, vibrators etc..  :icon_mrgreen:

Also, built a couple buffers and neither one worked, and by that I mean they didn't eliminate the hum? Don't really understand that either since one of the buffers I built was the TS buffer? I built them on small pieces of perf board.

Edit: almost forgot, I also made a klon buffer, sounded real good but no cure for the hum either...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 15, 2013, 02:01:12 PM
Oh. Btw, i would recommend posting the issue att ssguitar.com, Roly and JmFahey over there got some serious experience and knowledge,
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: ggedamed on March 15, 2013, 02:22:56 PM
For the buffer magic to happen, the buffer must come first thing after the input jack. Did you put it, by any chance, after the bypass switch?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 15, 2013, 02:30:32 PM
For the buffer magic to happen, the buffer must come first thing after the input jack. Did you put it, by any chance, after the bypass switch?

Nope, it's first thing after the jack... I don't even have a stomp switch wired into this at this point.

When I use my retail TS7 I can just leave it in bypass and it does the same thing only the tube screamer part of the circuit is bypassed since the retail has buffered bypass. I think when the TS7 is in bypass it's going through both the input and the output buffer if I am not mistaken and only bypassing the TS circuit, then into the preamp?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: posmaster on March 15, 2013, 02:39:52 PM
My 2 (probably useless) pfennig

It really sounds like a ground loop from the sample MP3 and the description of it getting louder as you turn down your volume.

If you're shunting noise to the guitar output ground, and then it's somehow munging it's way into the Black Forest's ground that *could* explain it, as well as why the 18K resistor was helping...

That being said I hope this gets sorted for you.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 15, 2013, 02:47:25 PM
My 2 (probably useless) pfennig

It really sounds like a ground loop from the sample MP3 and the description of it getting louder as you turn down your volume.

If you're shunting noise to the guitar output ground, and then it's somehow munging it's way into the Black Forest's ground that *could* explain it, as well as why the 18K resistor was helping...

That being said I hope this gets sorted for you.

It's isolated, no? What could it be looping with? If I use it all by itself (with no other pedals) and running from battery I still get hum...  I am open to that idea but I just don't see what it could be in a loop with? Maybe the Line 6 USB interface that I am running into the computer with? But then again it does it on my mosvalve power amp also...? And again none of my other pedals do this hooked up the same way??? I am also getting my mains power from a APC XS 1500 which has regulated smooth AC power, no spikes, no dips just clean power. Tried plugging the 1spot directly into the wall to see if it might be the UPS system but still does the same crap...??? Even tried it in different rooms of my house and the hum follows... The only other thing is the metal plate in my skull and if I take that out my brains will spill out all over the carpet and my wife hates when I spill my brain on her nice berber carpet!  :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: caspercody on March 15, 2013, 02:54:10 PM
Do you have a battery power amp? Trying to see if you can hook this up with nothing plugged into a AC outlet (computer, amp...)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: posmaster on March 15, 2013, 03:05:41 PM
My 2 (probably useless) pfennig

It really sounds like a ground loop from the sample MP3 and the description of it getting louder as you turn down your volume.

If you're shunting noise to the guitar output ground, and then it's somehow munging it's way into the Black Forest's ground that *could* explain it, as well as why the 18K resistor was helping...

That being said I hope this gets sorted for you.

It's isolated, no? What could it be looping with? If I use it all by itself (with no other pedals) and running from battery I still get hum...  I am open to that idea but I just don't see what it could be in a loop with? Maybe the Line 6 USB interface that I am running into the computer with? But then again it does it on my mosvalve power amp also...? And again none of my other pedals do this hooked up the same way??? I am also getting my mains power from a APC XS 1500 which has regulated smooth AC power, no spikes, no dips just clean power. Tried plugging the 1spot directly into the wall to see if it might be the UPS system but still does the same crap...??? Even tried it in different rooms of my house and the hum follows... The only other thing is the metal plate in my skull and if I take that out my brains will spill out all over the carpet and my wife hates when I spill my brain on her nice berber carpet!  :icon_twisted:

Yeah - that's why I wasn't sure it was a ground loop - but that's really what it sounded like in teh sample . The old "guitar+cable as noise antenna" deali-o... and maybe ground loop isn't the exact right phrase...

I'm still a rank amateur at this pedal-building thing, but coming from 20+ years of wiring and re-wiring guitars that's what jumped out at me from the sample

*and please take anything that sounds like something super-obvious with the intention of wanting of getting this working, my clumsiness in expressing things graciously, and not a slight on your skills :-)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 15, 2013, 03:19:44 PM
I agree, according to your recording Jok3rx, it sounds like mains hum to me. Could be shielding, could be a ground loop, could be nearby equipment...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 15, 2013, 03:39:23 PM
I agree, according to your recording Jok3rx, it sounds like mains hum to me. Could be shielding, could be a ground loop, could be nearby equipment...


And I agree... But, nothing else (pedals) I have do this..? And, it doesn't explain the few others that have built this and described the same noise.. unless we all have noisy mains and ground loops...

Actually this is mild compared to when I first built it! I have brought the noise down some... It was unbearable in the beginning!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 15, 2013, 03:42:55 PM

*and please take anything that sounds like something super-obvious with the intention of wanting of getting this working, my clumsiness in expressing things graciously, and not a slight on your skills :-)

No man, it's all good! Any ideas welcome!! :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: ggedamed on March 15, 2013, 04:12:19 PM
With all the respect, this Sherlock Holmes/Hercule Poirot type collective analysis is very entertaining to me  :D.

It could very well a combination of causes.
Jim, try to disconnect the shield on one of the cable patches that go into/out of the pedal and see if it does anything.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 15, 2013, 09:36:40 PM
With all the respect, this Sherlock Holmes/Hercule Poirot type collective analysis is very entertaining to me  :D.

It could very well a combination of causes.
Jim, try to disconnect the shield on one of the cable patches that go into/out of the pedal and see if it does anything.

Well, I am glad you are getting entertained by all of this :icon_mrgreen: At least I am accomplishing something then...

I may be onto something... :icon_rolleyes: standby
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on March 15, 2013, 09:43:09 PM
I'm getting myself an AMT R1 to compare this side by side and check if the hum on my build is comparable to the original.The last time i tested this compared to real boogie amp was very good.Both same hum content(amp and Engl build).Hope that R1 will arrive sooner.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 16, 2013, 01:11:52 PM
I'm getting myself an AMT R1 to compare this side by side and check if the hum on my build is comparable to the original.The last time i tested this compared to real boogie amp was very good.Both same hum content(amp and Engl build).Hope that R1 will arrive sooner.

My AMT pedals are very quiet... I would say the P1 has the highest gain of the bunch since it has 6 gain stages... All of my pedals are quiet, except for the ENGL and Black Forest. Then again none of my other pedal have as much gain as these 2. Probably a 50k gain pot would bring them down to the gain level of the others... Would probably cure all noise problems also since mine clear up 100% noise wise when I turn the gain back about half way on the pedal...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 16, 2013, 01:25:45 PM
Jim, don't even joke about cutting gain from these things........
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 16, 2013, 03:50:50 PM
Jim, don't even joke about cutting gain from these things........

Here are my thoughts for whatever they are worth... Get a great tone, good amount of gain but not too much, then slap a tube screamer in front of it, end of story! Been doing it for years and I can always seem to get a killer heavy sound and very tight with very little noise! I am not the only person that thinks this way... Many hard rock, metal, death metal, prog metal players etc do this. Even if they have a preamp/amp that have a bat sh!t crazy ton of gain they will dail the gain back on the preamp and "jack it up" with a tube screamer or close variant! Just adds the magic ingredient plain and simple!

Here is a great example of this! Take note of the gain settings on both
(http://dl.dropbox.com/u/11178619/Preamps/Ola-Maxon-P1-Crate.jpg)

And here is what it sounds like. Pretty massive and heavy in my opinion!
http://dl.dropbox.com/u/11178619/Preamps/AMTCRATE.mp3

This is a "small" rig that Ola Englund threw together (that is him playing by the way) using an AMT P1 with the gain dialed way back, a Maxon OD808 with the level cranked all the way and the drive all the way off, then running into a Crate Powerblock (basically a stereo power amp with EQ) with the gain on 2 or 3 then running into a 1X12 cab and mic. I know the Powerblock is a full on stereo preamp/power amp but I do the same setup with my mosvalve and the P1 and get the same sound and same amount of gain... I can also run direct and get roughly the same sound and same amount of gain... It doesn't get any more simple than this!

So, what I am purposing is that we build these preamps with built in/on-board Tube Screamer/OD pedals... Fairly small circuit and you don't even have to have a tone pot.. If you know where you like the tone setting on the TS (like I do) then you never really change it unless you have a really bright or really dark sounding guitar. In that case then you can have the tone on a small trim pot inside the enclosure. All in all, with this you can reach that aggressive, massive "over the top" brutal high gain sound with very little hum or noise. Then if you want a crunch sound or clean sound there are any number of things you can do with switching to obtain these as well... This is just a "tried and true" winning combination that just can not be and has not been beaten in my opinion! Thoughts?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 16, 2013, 04:08:33 PM
Man, you gotta love Ola, he's the king of getting heavy tones out of just about any setup. As you know Jim, I am a fan of tube screamers and use one in all of my rigs. They just add the perfect amount of extra drive I need, so it sounds like a good plan to me. My Randall doesn't have TONS of gain, but with a TS in front and a PQ3 in the loop it's downright brutal! Add in the fact that I can blend a tiny bit of clean channel in over the red channel and it destroys small villages.
Ordering E3 parts now to finally get back into this thread. Thanks again for sharing!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 16, 2013, 04:28:49 PM
Man, you gotta love Ola, he's the king of getting heavy tones out of just about any setup. As you know Jim, I am a fan of tube screamers and use one in all of my rigs. They just add the perfect amount of extra drive I need, so it sounds like a good plan to me. My Randall doesn't have TONS of gain, but with a TS in front and a PQ3 in the loop it's downright brutal! Add in the fact that I can blend a tiny bit of clean channel in over the red channel and it destroys small villages.
Ordering E3 parts now to finally get back into this thread. Thanks again for sharing!

I believe this is "THE ANSWER" to the humming noise! I have tried this and this does work 100% with the E3 and the BF! Just lower the gain on the preamp by changing the gain pot value or just dial it back and the humming magically goes away! Then, slap a tube screamer in front of it and the "Screamin Eagle" is born! Done! :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 16, 2013, 04:45:17 PM
Ok, so the E3 layout and transfer from page 16 is the correct one to use without any changes, correct?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 16, 2013, 05:07:59 PM
Ok, so the E3 layout and transfer from page 16 is the correct one to use without any changes, correct?

Check your email... :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on March 16, 2013, 07:26:39 PM
Would you be so kind to share pcb layout with me as well?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 16, 2013, 07:32:31 PM
Many thanks Jim
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on March 16, 2013, 07:40:36 PM
Thanks Jim  :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 16, 2013, 07:59:12 PM
Man, you gotta love Ola, he's the king of getting heavy tones out of just about any setup. As you know Jim, I am a fan of tube screamers and use one in all of my rigs. They just add the perfect amount of extra drive I need, so it sounds like a good plan to me. My Randall doesn't have TONS of gain, but with a TS in front and a PQ3 in the loop it's downright brutal! Add in the fact that I can blend a tiny bit of clean channel in over the red channel and it destroys small villages.
Ordering E3 parts now to finally get back into this thread. Thanks again for sharing!

Got any really compact/small TS808 layouts? I know the Son of Screamer and the Son of Clay Jones are small but they are missing the buffers and that may be key in the way they sound with these preamps...? Any good mods that would play nicely with these preamps? If you don't have a small layout I can make one, just thought I would ask in case... The different clipping options are not really that important to me since I don't really use it in the traditional sense...  

And by using the TS with the level maxed and the gain all the way off it's really acting as a front end booster of sorts, maybe a treble booster or something? Anybody know what would create this effect without going through the trouble of making a full on tube screamer? I have tried boosters like the SHO and the likes but they don't produce the same effect, at all! They are good for boosting the signal after the preamp but sound like a mess in front!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 16, 2013, 09:21:03 PM
The Brian May treble booster sim in GR5 does almost the same effect as the TS level knob.. I never really tried one in real life, only simulated pedal on simulated amps... Sounded very good and totally as good as the TS level drive effect!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: euronymous0001 on March 17, 2013, 12:56:23 AM
How about this one:
http://www.diystompboxes.com/smfforum/index.php?topic=1056.400 (http://www.diystompboxes.com/smfforum/index.php?topic=1056.400)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 17, 2013, 04:07:54 AM
How about this one:
http://www.diystompboxes.com/smfforum/index.php?topic=1056.400 (http://www.diystompboxes.com/smfforum/index.php?topic=1056.400)

Might try it..?

I tried the Brian May treble boost, threw it together on perf board in about 10 minutes... WOW!!! This thing is shmokin! I don't know if it will replace the TS but definitely a runner up! Makes leads a breeze and at the same time gives a tight bottom end! VERY COOL circuit!!! Highly recommend!

Edit: Crap man, I think the TS has met it's match!! The more I play with this the more I LOVE IT!!! Best 15 parts I have EVER thrown together!!!!!!!!!! :icon_mrgreen:

Used this - http://www.sabrotone.com/wp-content/uploads/2012/12/BrianMayTrebleBooster.gif

And no hum....  :icon_lol:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on March 17, 2013, 06:29:36 AM
Jok3rx, with this treble booster no hum even using 2SK117 or J201 at V1 and full gain setting?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on March 17, 2013, 07:57:45 AM
As far as boosters into high gain distortions goes i love using voodoo labs overdrive ( mine has tl082 inside ). Tight lows good mids and singing highs. My guitar is in standard C/drop A#. I can;t wait to try it with E3.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on March 17, 2013, 10:05:04 AM
Maybe try something teensy like an LPB or SHO.
If it works, it would be pimps to squeeze it into the enclosure and add a knob.

(ps - pimps means "very easy" in the West of Scotland)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 17, 2013, 11:56:23 AM
Tried SHO and the likes and don't like it.. at all! Doesn't have the same effect as the TS level drive.

I really like the treble booster but the TS still wins, nuff said.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: euronymous0001 on March 17, 2013, 12:06:47 PM
i think that the gain of the booster in front of the E3 is of lesser importance than that of the frequencies it is boosting. since the TS has a midhump, fullrange booster are not what is needed for this application. the "beginner" project, a.k.a. gus npn boost is good for this job. treble boosters is also good since it removes the low frequencies which will make the sound muddy
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 17, 2013, 12:21:57 PM
The SHO boosts all frequencies, so it is useful for clean or crunchy sounds, for high gain it becomes too muddy.

When you want high gain you want a mid boost (TS) or treble boost (which sometimes ends up being not much more than a mid-boost since a lot of the distortion harmonics of the treble frequencies are too high for the speaker to reproduce at significant level).

Why does the mid-boost of the TS make high-gain so good? Here is how I understand it:

1) Basically you want the bass to distort not too much since the harmonics will all be heard. Too much disto and it gets muddy, you want to keep it tight, so not much boost possible.

2) The mids can distort quite a bit and a good part of the harmonics will fall out of the freq band of the speaker anyway. Plenty of leeway for a boost available here, but too much mid sounds nasally so you will have to get rid of some in the post-disto eq.

3)The trebles can distort, so there is leeway for a boost, but anyway most of the harmonics will fall out of the freq band of the speaker except low harmonics which give just enough meat to the high register. So boost is ok, but can sounds shrill if no eq/natural speaker roll-off/cab sim later in the chain.

So you put a TS to have a mid-boost as pre-eq, put your distortion, then have a TMB tonestack with a mid-scoop to get rid of the excess of mid which can sound nasally and here you have it, a high-gain disto that sounds tight but not nasally or shrill.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: euronymous0001 on March 17, 2013, 12:26:09 PM
how about the demeter fat control?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 17, 2013, 12:39:26 PM
The treble booster has the tight edge boost effect like the tube screamer - But - It has a wind tunnel type sound in the background. You can get it to where the wind tunnel sound is gone but at that point it doesn't give enough boost or edge. So, back to the drawing board as far as boosters go... No worries, the tube screamer still kills it!! I suspect any good tube screamer variant will work very well!! I would say refer back to "Reply #598" at the bottom of page 30 for reference.... Easy to get side tracked with all of these circuits. 
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 17, 2013, 03:38:03 PM
Still looking for the cause of your hum, even if it seems fine with a TS, it is still not satisfying.

So I thought about a possible ground loop within your pedal:

On your layout you have too many ground in/outs I think.

There should be only 2 to be optimal. One ground coming from the power supply, and one ground going to one of the jacks, then you connect the ground of one jack to the other one with a wire. It will exclude the metallic enclosure from forming a ground loop with the ground track on your PCB (there is still a ground loop unless you use insulated jacks, but it does not pass though the PCB at least). It would be also good to make a ground fill instead of a ground track.

Not sure that's the problem, but that is the only ground loop I see here, and it seems you did not have as many ground wires on some of your previous layouts and they did not hum.

Could it be it?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 17, 2013, 03:53:28 PM
Still looking for the cause of your hum, even if it seems fine with a TS, it is still not satisfying.

So I thought about a possible ground loop within your pedal:

On your layout you have too many ground in/outs I think.

There should be only 2 to be optimal. One ground coming from the power supply, and one ground going to one of the jacks, then you connect the ground of one jack to the other one with a wire. It will exclude the metallic enclosure from forming a ground loop with the ground track on your PCB (there is still a ground loop unless you use insulated jacks, but it does not pass though the PCB at least). It would be also good to make a ground fill instead of a ground track.

Not sure that's the problem, but that is the only ground loop I see here, and it seems you did not have as many ground wires on some of your previous layouts and they did not hum.

Could it be it?

You know, that is exactly what I thought (loop within the pedal) when people started saying it sounded like ground loop and I know there is nothing external that it could be in a loop with. So, I did just about exactly what you said and still got the hum. Now I have what I guess is a star ground... Only 2 connections to the board connecting in the same place, the rest of the ground connections are off-board to one connection and yes I do have insulated jacks... Also tried regular un-insulated jacks etc... hummin all the time. If I touch the trace side of the board around the gain pot connections the hum stops, also if I pick the pedal up and hold it up in the air with my head turned just a certain way and one foot slightly lifted the hum stops...

Kinda like this...
(http://theoffdutymime.files.wordpress.com/2012/10/captain_morgan_vv-789984.jpg)


Sun spot activity perhaps? lol wtf?

Seriously, maybe it is a board design problem of some kind? Maybe a trace or component is routed over or under something causing cross talk/noise? Mybe the circuit is too compact and needs to be spread out more..? Thoughts?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 17, 2013, 06:04:58 PM
Did you ground the case of your gain pot?

I think it comes down to layout since we basically tried everything else possible...

Is it you on the picture? :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 17, 2013, 07:54:17 PM
Did you ground the case of your gain pot? Tried that, did nothing except heat up my pot...

I think it comes down to layout since we basically tried everything else possible... This is possible

Is it you on the picture? It's Captian Morgan - http://www.captainmorgan.com/
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on March 17, 2013, 08:37:42 PM
if I pick the pedal up and hold it up in the air with my head turned just a certain way and one foot slightly lifted the hum stops...

hmmm weird,.....i guess you've tried everything ....but have you tried it in another room?...some lights can really piss me off with noise!....fridge....dimmer switches....cat.....etc.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 17, 2013, 09:59:17 PM
if I pick the pedal up and hold it up in the air with my head turned just a certain way and one foot slightly lifted the hum stops...

hmmm weird,.....i guess you've tried everything ....but have you tried it in another room?...some lights can really piss me off with noise!....fridge....dimmer switches....cat.....etc.

Actually I did try a different room and with battery and adapter power still the f%$#ing hum...  :icon_evil: Tried different guitars, swapped out all the fets, stood on my head, barked like a dog... the whole bit! HUMMMMMMMMM... The 18k resistor to ground on the input seemed to work the best and kills 100% of the hum and still retains about 90% of the gain and tone but still just killing that amount of the input tone coming from the guitar causes a substantial loss in my opinion... You really want to get the full tone and sustain of the guitar and preserve or enhance it, not pull it down... I think this preamp is just blazing wide open with gain like a screaming chainsaw with the J201 in the V1 spot. The guitar signal comes out of the first stage "balls out" and then hits those high gain mosfets and by the time it reaches the last one it's too much. I tried trim pots on the mosfets to get them tamed down a bit but it still didn't help. I think they are optimized the way they are set with the fixed resistors and any changes causes wild tone and gain loss..

I did audio probe this and most of the noise is on the 4th stage, slight noise on the 3rd and then substantial noise on the 4th... So, if the noise could be progressively reduced on each stage before the 4th stage it would probably get rid of the noise. How to do that? good question?

I have gone over this post since it's almost the same as the ENGL and no reports of this noise... But this guy hasn't posted in a long time or I am sure he would have jumped in by now.. Unfortunately his never made it off the bread board from what I can tell and he didn't make any layouts that I can find...?
http://www.diystompboxes.com/smfforum/index.php?topic=89399.0

What I lack in knowledge I make up for in persistence! I would rather work "smarter" vs. "harder" but that's what I got... If I didn't have to work for a living and I could attack this thing all day long every day I would have whooped it's @ss a long time ago! But, 2 or 3 hours every other night between 11:00PM and 2:00AM ain't cuttin it!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 18, 2013, 12:25:24 AM
Just looking at the AMT schematics and gut shots for the P1, B1, E1 and S1 noticed they all have 50k/A gain pots :icon_confused:
On my "like E1" schematic I changed the gain pot to 100k just because it worked and that was the only close pot I had at the time, so I left it like that.

Not that these 2 preamps are alike but the first stages are very similar... And this E3 has sh!t tons more gain over all than the E1 does!  
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: euronymous0001 on March 18, 2013, 01:30:07 AM
hmmmm...

how about a 100n cap between 9v and ground...

to quote MartyMart on post #18 http://www.diystompboxes.com/smfforum/index.php?topic=51863.0 (http://www.diystompboxes.com/smfforum/index.php?topic=51863.0)

Quote
"The extra 100nf filter is an RG tip, if I remember correctly - faster ESR helps to smooth the power faster than the
large 100uf, when used in conjunction with it. I use them often on higher gain circuits - then again, I could be talking absolute rubbish !!"

then again, I also, might be talking rubbish.   :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 18, 2013, 02:43:48 AM
Ok folks, I believe I have FOUND THE PROBLEM!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :icon_mrgreen:

My own stupidity mainly!

Ok, the shielded wire I thought was good enough, well, it wasn't "good enough"!

I pulled all the wiring out and rewired with "REAL" shielded wire (the kind with the F#^$ing tin foil wrapped around the inner wire) and whadaya know! No more HUM!!!!

Make sure you have it shielded right up to the board and only connect the ground braided wire on one side for best result! Shielding is most important on the input obviously but, I would "SHIELD EVERY F#%#ING THING" if you can! I tested it again and again to make sure I wasn't just imagining things and
NO F#%#ING HUM!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!  :icon_mrgreen: :icon_mrgreen: :icon_mrgreen: :icon_mrgreen: :icon_mrgreen: :icon_mrgreen:

So go to Smallbear and get some SHIELDED WIRE!!!!
http://www.smallbearelec.com/servlet/Detail?no=796

Edit: Oh, and same goes for the Black Forest!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Somicide on March 18, 2013, 04:11:57 AM
bout damn time, Jim ;)

The suspense was killing me!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on March 18, 2013, 07:52:51 AM
WHOOOHOOOOO :icon_twisted:....., so the debugging thread should now include waving it about in the air too ;D

surprised you didn't have a bonus radio though...

good on ya man, i admire your persistence...but hey if you want ''that sound'' its worth sweating blood over imo....cool, hope your stress levels are getting back to sub normal... ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 18, 2013, 07:58:09 AM
I guess it was somehow a layout problem then...

So did you shield the wires to the pots in the Black Forest? Or did you have a pot-on-board version (I lost track).

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 18, 2013, 09:00:00 AM

So did you shield the wires to the pots in the Black Forest? Or did you have a pot-on-board version (I lost track).



Nope... All off-board pots on the Black Forest! Gotta watch that gain pot mainly, and never used shielded wires on it or the input! I have a new version of the Black Forest with all on board pots but haven't posted it, yet...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: euronymous0001 on March 18, 2013, 09:53:20 AM
kudos!

now, when can i have the time to make this  :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 18, 2013, 10:20:08 AM
Good for you Jim! Now you can finally sleep  :icon_eek:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on March 18, 2013, 07:28:56 PM
Jim, you made me open again my Engl build hahaha thanks for the great discovery.Have to look for good shielded wires.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 18, 2013, 07:42:59 PM
Jim, you made me open again my Engl build hahaha thanks for the great discovery.Have to look for good shielded wires.

Fretz - SHIELD THE SH!T OUT OF IT!!!  :o

Well, "sometimes" the CD/DVD-ROM drives in your computer have an audio cable that runs to the sound card on the mother board and sometimes they are shielded really well but, sometimes they are not... Don't ask me how I know this :icon_rolleyes: Anyway, got lucky and found a really good one in an old Dell, big thick blue wire with the tin foil... Good stuff!!

I really need to break down and buy a spool of it so I don't have to keep "hit or miss" using these scrap wires... I guess if you are gonna be a serious high gainer this is like a golden rule not to be broken!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 18, 2013, 07:53:03 PM
Ok, What's next? New Black Forest, Krankenstein, Buzzefall (whatever the hell that is? but it sounds cool!), VHT, Modern Soldano 100, Mesa Triple Rectifier - jfet/mosfet version or what else? Requests?

Ok, I know... Slow down, right? It's just that all of the above schematics are almost the exact same except for values and some small differences so, I can use/modify the same layout!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 19, 2013, 08:21:36 AM
What about a Mk IV, a Dark Terror, a JVM 410, a Carvin Legacy, a Laney AOR? I am trying to go off the beaten path here.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on March 19, 2013, 08:49:36 AM
Installed back the 2SK117 at V1 and still having noise issues even with shielded wires.Maybe my wires are not good enough(gutted from old TEAC 4 track recorder)or my layout because is too compact to fit 1590B enclosure.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 19, 2013, 09:13:46 AM
Installed back the 2SK117 at V1 and still having noise issues even with shielded wires.Maybe my wires are not good enough(gutted from old TEAC 4 track recorder)or my layout because is too compact to fit 1590B enclosure.

Do they have the tin foil around them?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fretzburner on March 19, 2013, 09:20:23 AM
No tin foil,i can't find it here in my location.i have one with tin foil but for mic cable very big in diameter and next to impossible to install.Jim did you replace your gain pot to 50k?I'm still using same as the schematic.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 19, 2013, 10:52:09 AM
Ok, What's next? New Black Forest, Krankenstein, Buzzefall (whatever the hell that is? but it sounds cool!), VHT, Modern Soldano 100, Mesa Triple Rectifier - jfet/mosfet version or what else? Requests?

Ok, I know... Slow down, right? It's just that all of the above schematics are almost the exact same except for values and some small differences so, I can use/modify the same layout!

Krank or VHT please?  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 19, 2013, 03:36:31 PM
Would love to see a MKIV, but actually i'm so happy with the combination of Black Forest, My 7-string ESP LTD MH-417 and my Randall RH100 i doubt i will replace it. It's perfect!

My next step is gonna be trying to make it digitally controlled, together with my AMZ boost and Delay in the same enclosure to make presets instead of all the stomping required at the moment, but the pedal will make it's third gig now this Friday, and the Release Party for our album the 29th. :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 19, 2013, 05:06:17 PM
Finally, another Randall user  :icon_smile:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 19, 2013, 05:29:34 PM
No tin foil,i can't find it here in my location.i have one with tin foil but for mic cable very big in diameter and next to impossible to install.Jim did you replace your gain pot to 50k?I'm still using same as the schematic.

Gain pot is still 100k on mine and I am using a J201 for the first stage.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 19, 2013, 05:57:59 PM
Would love to see a MKIV, but actually i'm so happy with the combination of Black Forest, My 7-string ESP LTD MH-417 and my Randall RH100 i doubt i will replace it. It's perfect!

My next step is gonna be trying to make it digitally controlled, together with my AMZ boost and Delay in the same enclosure to make presets instead of all the stomping required at the moment, but the pedal will make it's third gig now this Friday, and the Release Party for our album the 29th. :)

You mean like this?
http://www.sabrotone.com/?p=814
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 19, 2013, 06:27:50 PM
Actually built that one, but it has some big flaws. :/ Insane oscillation, couldnt get any gain whatsoever without squealing worse than the guy in the Burt Reynolds movie "Deliverance". Posted it on ssguitar, where it got shot down really bad.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 19, 2013, 06:31:54 PM
Actually built that one, but it has some big flaws. :/ Insane oscillation, couldnt get any gain whatsoever without squealing worse than the guy in the Burt Reynolds movie "Deliverance". Posted it on ssguitar, where it got shot down really bad.

lol, I kinda figured something was not quite right or we would hear more about it... Thanks for the verification  :icon_wink: Wonder why it was shot down though? Looks like a good idea to me!

Whats up over at ssguitar? Seems like a ghost town... not much activity :icon_rolleyes:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on March 19, 2013, 11:04:24 PM
Hey, you guys built a madbean upper decker?  I just finished mine on the weekend.  Brian Wampler is correct in saying it sounds like 'an amp in a box'.  The bottom end from this thing is amazing!  I (personally) have never heard so much bottom end 'chug' from a distortion pedal.  its a gain-tsunami.  (its based on the wampler triple wreck btw) I'm going to upload a video of it tonight, ill post it here if you want to see it?

Sorry just thought this was a good place to mention it :D

Paul
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 19, 2013, 11:36:07 PM
Please post the vid Paul, I love madbean's stuff  :icon_biggrin:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on March 19, 2013, 11:51:25 PM
Will do!  It takes alot to impress me these days, this pedal is awesome i love it.  I'll post the link after its uploaded to metube. :)

* dont mean to hijack your thread joker, just thought that it was full of like minded people \m/  :icon_evil: \m/  :D

Paul
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 20, 2013, 02:41:54 AM
Will do!  It takes alot to impress me these days, this pedal is awesome i love it.  I'll post the link after its uploaded to metube. :)

* dont mean to hijack your thread joker, just thought that it was full of like minded people \m/  :icon_evil: \m/  :D

Paul

Paul,

Anything "like minded" is more than welcome by me!!! I loosely followed the whole Triple Wreck post over at FSB but never got around to building it... Seemed there was a bit of a question or problem with the boost circuit but I don't know that it really needs the boost, does it? I would be inclined to use the good old tube screamer for boost myself... I am not sure if this is a "preamp" or more of a distortion pedal and I am not really sure what the hell the difference is anymore with some of these pedals? In any case, I would really like to hear what this sounds like running into the fx return of an amp or even running direct!?

Paul, can you do a "direct demo" of some sort? Just curious what it sounds like...?

To quote indyguitarist "BW" from that thread:
"On the boost side, if you are experiencing gating it\'s because you need to either sort through a batch of transistors in order to get the voltages and gains right, or you need to use a trimmer and set it up that way. We sort through a ton of \'em to make sure they have a specific gain and voltage."

I think I would do without the boost myself... I did build the boost circuit at one time and tried it on some other pedals and didn't like it.

Seems like BW has a fondness for the 4580's since they are in almost every pedal he designs... I tend to like those as well!
I know RCustoms made a layout using a TL074 and a TL072 instead of three 4580's with real good reports. The thing is nobody ever does any F#$%ing demos and that blows my mind since that's really what it's all about, huh? I mean I ain't the best player in the world but at least I will make some F#%$ing noise! Somebody says "this is the best pedal I have ever heard" and then no demo? wtf  ???

So, after that little rant I am looking forward to hearing your demo...  :icon_biggrin:

Edit: Upper Decker lmao! I think I am gonna use the Urban Dictionary to name all of my pedals from now on :icon_lol: As a matter of fact I think I will re-name the Black Forest to the Angry Dragon!
http://www.urbandictionary.com/define.php?term=angry%20dragon

What should I name the Engl?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on March 20, 2013, 03:58:56 AM
Ive recorded 2 videos of it (on the weekend).  I upload 2 videos a week to my channel usually, I find if I spam my channel, people don't have time to watch them and they tend to go unnoticed.  So the first one (the sound demo) is uploading now, and the build report will follow probably on sunday.

I hadn't seen the FSB thread about it!  Just built it off madbeans layout.  You are right!  I said in the 'build report' how I found any other IC to not sound anywhere near as good as the 4580.  Even replacing one.  Sounds like a different pedal.  3x4580 was the best sounding combo to my ears.

I messed up the offboard wiring.  The boost ended up after the effect.  I just couldn't wire it the other way around...tried 3 times and keep stuffing things up.  So I figured something is better then nothing and wired it up after the effect.  Like you said, any boost infront of it will probably do anyway...

Someone brought that definition up on madbean forum (upper decker) and we all had a laugh :) hadn't heard of that one before. lol angry dragon

Paul

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 20, 2013, 04:17:37 AM
That would work as a band name too :P "The angry dragons"
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on March 20, 2013, 04:25:17 AM
I probably went a bit high on the top end and low on the volume, but heres the demo anyway.  Into the front, amp is a bad cat hot cat, good amp, but only 1x12inch.  Guitar is a Gibson sg.  Its a cool pedal, I really like it!

Paul

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 20, 2013, 11:10:13 AM
Good vid Paul, sounds nice and fat but not flubby. Love those knobs!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on March 20, 2013, 06:19:19 PM
Thanks pakrat!  This was a slap together build.  I didnt have much time to spend on it, so it was a bit rushed.

I usually dont post my sound demos around here, but this pedal just sounds so dam good i couldnt resist.

Anyway, hope you like it.  Now its back to you joker :D

Paul
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 20, 2013, 06:31:38 PM
Paul,

Damn! That thing has a crap load of gain huh!? Sounds damn good to me!! :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: meffcio on March 20, 2013, 07:20:45 PM
Honestly, as always, I lost track where's the final version of this project, if there is one. It's always the same, it's finished, but wait, there's a lot of hum, and then a whole bunch of debugging goes on. Seriously, same shit already happened. :D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: chromesphere on March 20, 2013, 07:23:41 PM
Honestly, as always, I lost track where's the final version of this project, if there is one. It's always the same, it's finished, but wait, there's a lot of hum, and then a whole bunch of debugging goes on. Seriously, same sh*t already happened. :D

There are multiple projects in this thread, and just to confuse it further i added a video demo of a build that has absolutely nothing to do with any of them :D :D

Paul
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 20, 2013, 08:01:00 PM
Honestly, as always, I lost track where's the final version of this project, if there is one. It's always the same, it's finished, but wait, there's a lot of hum, and then a whole bunch of debugging goes on. Seriously, same sh*t already happened. :D

I think the latest version of the Engl is on page 16 post#304... Post#307 for the latest PCB transfer. I think there is a new version of the Black Forest coming, so you might want to wait on that one.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: hari on March 28, 2013, 02:03:39 AM
Hello, I have a plan to build high gain distortion pedal again  :) ( I've build sansamp GT2, Metalzone (bought a kit), Shredmaster, etc).

I just want to make sure myself :

The latest Black Forest PCB layout is on page 12, (?)

ENGL on page 16 post#304... Post#307 for the latest PCB transfer

and I'll keep reading this topic

 :icon_smile:


Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 28, 2013, 03:21:50 AM
yeah. Those are the versions which i have built, can confirm both as working. :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Maik on March 28, 2013, 05:25:57 AM
Hey stormbringer, what about hum?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 28, 2013, 08:35:38 AM
Stormbringer,

Do you prefer the Engl of the Black Forest overall? I will build one someday, but only one of them so I have to choose wisely. I know Jok3rx tends to prefer the Engl. I am more a lead type of guy, but i of course enjoy chuncky rhythm :icon_evil:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 28, 2013, 01:03:14 PM
Stormbringer,

Do you prefer the Engl of the Black Forest overall? I will build one someday, but only one of them so I have to choose wisely. I know Jok3rx tends to prefer the Engl. I am more a lead type of guy, but i of course enjoy chuncky rhythm :icon_evil:
I think the Black Forest still has some noise issues to be worked out. I can't comment on the Engl since I haven't built it yet, but I've heard it's nice and plan to build it soon. My Black Forest has noise at the moment but it sounds great otherwise and the lead tone is really good!
Here is my BF just finished last night:
(http://i1072.photobucket.com/albums/w375/pakrat70/SEVENLEAF%20EFFECTS/BLACK%20FOREST/Black_Forest_zps3b1990e1.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 28, 2013, 01:15:07 PM
Looks good... Somehow...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 28, 2013, 08:27:33 PM
Sorry... contents of post has been deleted!

Moderator.. Oh moderator..... Helloooo? Please oh please would you delete my post!? :'(  
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 28, 2013, 09:49:53 PM
666th post..... YIKES!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 29, 2013, 10:24:00 AM
Well, i built the black forest with noise gate option, and it's virtually silent using my 7-string with active pickups. I havent added noise gate and boxed the Engl yet, so far it hums a little more.

Right now i'm using the Black forest as my main dist, but i plan to use the engl aswell. I will use the black forest for heavy riffs, and the Engl for Leads. But both pedal does both parts very good. It's just my personal preference.

I would recommend Building both actually, they are far from expensive, and doesnt really take any time to build.

Unfortunately i didn't have the Black forest when we recorded our album or i would have used it, but we're gonna record a new song soon, and i will use both pedals when reamping. :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 29, 2013, 11:14:41 AM
@stormbringer which version of the Black Forest did you build please?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 29, 2013, 08:35:05 PM
Well, i built the black forest with noise gate option, and it's virtually silent using my 7-string with active pickups. I havent added noise gate and boxed the Engl yet, so far it hums a little more.

Right now i'm using the Black forest as my main dist, but i plan to use the engl aswell. I will use the black forest for heavy riffs, and the Engl for Leads. But both pedal does both parts very good. It's just my personal preference.

I would recommend Building both actually, they are far from expensive, and doesnt really take any time to build.

Unfortunately i didn't have the Black forest when we recorded our album or i would have used it, but we're gonna record a new song soon, and i will use both pedals when reamping. :)

Can you tell us which version you made, parts/values used etc...?

I think I am gonna start over from the beginning and go from there... See where it went wrong? It worked up until shortly after the 5th gain stage was added. If I remember it worked after the 5th stage but something I did after that started the hum. I don't think I ever tried to back out of it and go back to the way it was right after the 5th stage...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 30, 2013, 01:14:35 PM
I made the 4.1 Version, used your layout, but on perfboard, i did however move the tonestack cap-section down below the rest to make the board a little less wide to fit in my box.

All resistors spot on values, Metal Film 0.6W except for the 1.5k, which are 2 series carbon to obtain the right value, All capacitors are panasonic EQCB, PC12 or Wima MKS2, also, the pf range i used only ceramic for C3, rest are Panasonic EQCB or WIMA FKP2 (polyprophene).

Shielded wires In, out and to gain pot. It is in series with my delay in the box aswell though, not true bypass as i want the trail-feature, but just a jfet switch it's passing through, so not coloring anything really.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 30, 2013, 02:29:30 PM
I made the 4.1 Version, used your layout, but on perfboard, i did however move the tonestack cap-section down below the rest to make the board a little less wide to fit in my box.

All resistors spot on values, Metal Film 0.6W except for the 1.5k, which are 2 series carbon to obtain the right value, All capacitors are panasonic EQCB, PC12 or Wima MKS2, also, the pf range i used only ceramic for C3, rest are Panasonic EQCB or WIMA FKP2 (polyprophene).

Shielded wires In, out and to gain pot. It is in series with my delay in the box aswell though, not true bypass as i want the trail-feature, but just a jfet switch it's passing through, so not coloring anything really.

That's great man, really appreciate you giving that info!! Not sure what your magic is but I am really glad it works for you!!! Could you post a sound clip and or some gut shots maybe? I have another BF with on-board pots but minus the extra jfet/5th gain stage... Maybe I will make it optional where you can add it or leave it out if you want. Might post it today if I get a chance... Thanks again for your help!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 30, 2013, 03:12:37 PM
I already had shielded wire for input so I just put shielded wire in for output and gain pot and still have noise. The only difference between my and stormbringer's build now is poly caps instead of the ceramics and relocating the tone stack.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 30, 2013, 03:40:09 PM
Correction.... mt noise levels have dropped after closing the box. It's definitely better than before!

@stormbringer Is your build completely noise free??
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 30, 2013, 04:59:21 PM
I will record some samples. Although my pedal is currently in our rehearsal studio, will bring it home monday and record.

It is very silent using my seven string. But that guitar have great pickups. Active emg's. It does hum some on my other guitars. I run it with noise gate set to max.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 30, 2013, 05:23:13 PM
I run mine with emg81's also, and with gate at max but still have a little noise. It's not too bad though and the pedal sounds great! Thanks for the info stormbringer.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 30, 2013, 05:43:15 PM
If you guy have noise with your active pickups, I will have ten times as much with my passive DiMarzio's!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 30, 2013, 05:58:43 PM
I just ran a test for you jymaze. I tried 3 different guitars with different passive pickups and it squeals like crazy with gain turned passed 4 on all of them. I tried duncan distortion, dimarzio x2n, and a bare knuckles warpig. Active Emg's have no squeal....
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 30, 2013, 06:40:15 PM
Thanks for the test Pakrat, that is what I thought...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 30, 2013, 07:37:19 PM
The squeal goes away when I back off the tone on my guitars.  It may be fixed by reducing the boost resistor? I'll check that and report back, might need an active and passive switch setup here.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 31, 2013, 06:08:05 AM
New BF.... Layout not verified, yet. This is the normal 4 gain stage version and buffer after tone stack. This should not have a noise problem and still have a very good amount of gain.

(http://dl.dropbox.com/u/11178619/New%20Preamps/Blacker%20Forest%20-%20On-board%20Pots%20Small.png)

Larger Image
http://dl.dropbox.com/u/11178619/New%20Preamps/Blacker%20Forest%20-%20On-board%20Pots%20Large.png

Board Transfer
http://dl.dropbox.com/u/11178619/New%20Preamps/Blacker%20Forest%20-%20On-board%20Pots.pdf
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on March 31, 2013, 09:24:43 AM
Thanks Jok3rx. I remember you said it lacked balls without the 5th gain stage, but I am sure it is still very much kicking anyway.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 31, 2013, 09:37:29 AM
Thanks Jok3rx. I remember you said it lacked balls without the 5th gain stage, but I am sure it is still very much kicking anyway.

It still has balls and I believe I said that before I found the boost resistor...? And, it can be driven with a tube screamer to achieve the same or better... Main thing is no hum! I will make one with the 5th stage also. I was thinking of making one with a couple mosfet stages too (jfet/mosfet/jfet/mosfet/jfet/TS/jfet)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 31, 2013, 11:17:26 AM
I'll be happy to build and confirm your new stuff mate. Although i got a couple of projects i need to get done first. (Designing a programmable pedalboard 4 momentary buttons, 6 send/returns and controlled by a pic and lcd, in order to make it programmable).
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 31, 2013, 12:37:28 PM
I'll be happy to build and confirm your new stuff mate. Although i got a couple of projects i need to get done first. (Designing a programmable pedalboard 4 momentary buttons, 6 send/returns and controlled by a pic and lcd, in order to make it programmable).

Ah... I still have my PIC programmer from making rapid fire xbox controllers. I used WinPic and 12F683's, I could get them to do quite a few things. I wish I would have kept going with it...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on March 31, 2013, 01:00:35 PM
I work as a programmer, so it comes quite natural to work with pics, but if you want an easy way of coding for pics, check out flowcode, does it for you with block diagrams. Its not perfect, but can help you alot.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 31, 2013, 01:21:03 PM
I work as a programmer, so it comes quite natural to work with pics, but if you want an easy way of coding for pics, check out flowcode, does it for you with block diagrams. Its not perfect, but can help you alot.

I might get back into it if I ever come up with a nice preamp that I am satisfied with...  :icon_rolleyes:

I decided to start another thread for the AMT E1 clone but I posted it in "The Lounge" instead of Members Only... Dumb I am!
http://www.diystompboxes.com/smfforum/index.php?topic=102143.0
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on March 31, 2013, 09:57:01 PM
Parts ordered, Thanks JOK3RX!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 01, 2013, 03:40:47 AM
Ok, very good news!!! I am going to bed a happy man! I built this thing with 4 gain stages and it is THE BEST!!! No noise, no hum, no buzz!!! Tons of gain... Tone stack works very well, tone to the bone! Boost switch works very well! Wide switch works very well! Everything kills!!! I am DONE with this and this one is going into a box!! Love it!!! This is better than the ENGL, better than all of my stuff period!!! Details tomorrow, I gotta get some sleep 8) Stay tuned!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on April 01, 2013, 09:38:39 AM
Glad you could get that to work! I am working on one of these right now and it was the same: Too much gain makes it noisy and squealy. It still has 5 stages, I think I'll either dump one or scale down the gain at least on 2 stages. I hate desoldering so it will be scaling down the gain. It is very specialized and its goal is to give you one specific sound: Codename is "Petruccifier"... I hope it will be postable soon, I am sure some people will be interested. Basically it is an attempt at a Mk IIc emulator, with less knobs. I can tell you it is scoopy!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 01, 2013, 11:47:22 AM
Ok, very good news!!! I am going to bed a happy man! I built this thing with 4 gain stages and it is THE BEST!!! No noise, no hum, no buzz!!! Tons of gain... Tone stack works very well, tone to the bone! Boost switch works very well! Wide switch works very well! Everything kills!!! I am DONE with this and this one is going into a box!! Love it!!! This is better than the ENGL, better than all of my stuff period!!! Details tomorrow, I gotta get some sleep 8) Stay tuned!
Well it's about friggin' time!!  :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 02, 2013, 05:51:20 AM
This is really puzzling me ??? I can't figure out why this one has so much gain with 4 gain stages? I'm not complaining at all but this just isn't making any sense... It has as much if not more gain than I was getting with 5 gain stages! I don't remember it having anywhere near this much gain when I built the first one with 4 stages!? Weird!? WTF?? Wondering if I got a resistor wrong somewhere but I can't find anything, yet. When I get time I am gonna have to go over this thing thoroughly!

jymaze - Petruccifier? I want one!  :icon_biggrin:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on April 02, 2013, 09:05:50 AM
Maybe you used a combination of fets that yield higher gain just by chance... I did a run of jfet testing last week on 2N5457 and J201. Quite a bit of variation, sometimes wild. I will just use the ones with the lowest Vgs off since they yield higher gain. It is especially crucial for the first stage because more gain equals less noise generated there. I would select low Vgf off for better results (at least I think it would be better).

I am glad all this got finally fixed. I was right somehow... drop a stage. You can keep your AMT pedal though... :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 02, 2013, 06:46:52 PM
Maybe you used a combination of fets that yield higher gain just by chance... I did a run of jfet testing last week on 2N5457 and J201. Quite a bit of variation, sometimes wild. I will just use the ones with the lowest Vgs off since they yield higher gain. It is especially crucial for the first stage because more gain equals less noise generated there. I would select low Vgf off for better results (at least I think it would be better).

I am glad all this got finally fixed. I was right somehow... drop a stage. You can keep your AMT pedal though... :icon_wink:

I thought about the jfets but then I remembered they are the same jfets that I had in the first BF which I thought didn't have enough gain using only 4 gain stages, remember? That was the only reason I added the extra stage... So, the jfets I am using now are the same ones that I used before minus one of course. In any case, I even tried others and it still has a ton of gain.. weird? I haven't really had time to go over it again since I built it but I might have a look at it tonight.

Waiting for the Petruccifier!!!  :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 02, 2013, 10:23:57 PM
Ok, totally off topic... ::)  Anybody ever try the EMG active circuit?? Like either of the two on this link?
http://revolutiondeux.blogspot.com/2012/06/active-pickups-how-do-emg-do-it.html

I want to mod my el cheapo' 7 string stock pickups but wondering if it's a waste of time?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 02, 2013, 11:21:56 PM
Wow, that's very interesting, I have a bunch of el crapo pickups to try this on.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 03, 2013, 12:10:35 AM
Ok, back to the BF... I don't even have shielded wires on this one and it has very little noise (but I HIGHLY RECOMMEND using shielded wires!)

I think I know where all the gain is coming from! The boost resistor! Instead of trying a bunch of resistors I just stuck a 100k trim pot on there and dialed in what I thought was the right amount of high gain vs. noise ratio and that is plenty!! Not sure of the value as I have not measured it yet since I have been playing non stop since I built it!  :icon_mrgreen: Which is nice for a change!!! I think this thing sounds better than ever!! I am also using the Hotline cab simulator and I am loving it!!! Very Happy I am!! :icon_biggrin:

Edit: Oh and by the way, if you put the 4.7uF electrolytic on the first stage on a switch between 1uF and 4.7uF it's like a "tight" switch! Tightens up the bottom end! Or you can put them both on a pot and have a fake variable cap and dial in the tightness! :icon_wink:

jymaze - Still waiting for the Petruccifier!!! See, you shouldn't have said anything... :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 03, 2013, 01:00:34 AM
A "tightness" pot sounds great, and no gate on this one?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 03, 2013, 01:55:17 AM
A "tightness" pot sounds great, and no gate on this one?

No gate, but you can add it in if you want...I would be inclined to put it in if it were foot switchable but I really don't want another footswitch... Unless I build it into a 1590DD? But, I really want to add a clean channel! That's one thing a lot of these preamps lack is a clean channel and they just have true bypass. I don't really like that... It's good for home/studio/recording applications but not so good for live..
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bluesdevil on April 03, 2013, 02:25:23 AM
Just checking back in for updates..... wow!!
Now there is finally success with a 4 stage BF?
I may desolder parts off my ENGL and try my luck with it.
Never could quiet down the ENGL without neutering the sound I liked, but I also didn't try shielding the leads yet. After reading about the 4 stage Black Forest I may wait to use my enclosure for that!
Keep on rockin'!!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 03, 2013, 04:51:19 AM
Ok, totally off topic... ::)  Anybody ever try the EMG active circuit?? Like either of the two on this link?
http://revolutiondeux.blogspot.com/2012/06/active-pickups-how-do-emg-do-it.html

I want to mod my el cheapo' 7 string stock pickups but wondering if it's a waste of time?
I did. It balances highs, lows and mids nicely. The sound never turns to mud, even at lower tuning ( drop a# on my 6 string sg, dean markley strings 0.10-0.46 ).  And it's not buzzing like a mosquito. I did this with my old ibanez v8. My guess is that it may sound better with a better pickup. Ps i'used the first schematic, not the pcb by bajaman or the other schem that uses tl061. Only modification that I did was 2 165k resistors instead of 137k's. You should give it a go. Since the parts are so cheap and easy to find.

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 03, 2013, 08:20:38 AM
Thanks for the info Miša, adding this to my ever growing "to do" list  :icon_eek:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 03, 2013, 09:01:51 AM
Ok, totally off topic... ::)  Anybody ever try the EMG active circuit?? Like either of the two on this link?
http://revolutiondeux.blogspot.com/2012/06/active-pickups-how-do-emg-do-it.html

I want to mod my el cheapo' 7 string stock pickups but wondering if it's a waste of time?
I did. It balances highs, lows and mids nicely. The sound never turns to mud, even at lower tuning ( drop a# on my 6 string sg, dean markley strings 0.10-0.46 ).  And it's not buzzing like a mosquito. I did this with my old ibanez v8. My guess is that it may sound better with a better pickup. Ps i'used the first schematic, not the pcb by bajaman or the other schem that uses tl061. Only modification that I did was 2 165k resistors instead of 137k's. You should give it a go. Since the parts are so cheap and easy to find.

Cool... I am gonna make a couple then! So, you used the LM4250, right?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 03, 2013, 09:42:10 AM
Yep.
Any way the sound is great i was always wondering how could i get that meshuggah "clean" high gain sound. Clean, meaning that i could actually hear every note, and every mistake :icon_redface:. At this very moment I'm giving my old epiphone pickups a split option. And bridge is getting it's ass activated.

Ps I've etched E3 and I'll give it a go with this activated pickup. I think that it should fix it's hum issues. Than again i might be wrong :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on April 03, 2013, 10:22:46 AM
So, the latest posted layout is the current version? :) Building it as soon as i get my parts.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 03, 2013, 11:15:09 AM
So, the latest posted layout is the current version? :) Building it as soon as i get my parts.

If you are referring to the Black Forest 4 stage with the on-board pots the answer is, Yes.

I have another with 5 stages but I think I am gonna scrap that version...

BTW: I have not verified that layout... I used the same schem just a different layout. Might want to look it over for any booboo's :icon_redface: But I believe it's right.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 03, 2013, 12:48:03 PM
Here is a quick clip I threw down over a random drum beat... be nice now, been a long time since I rock-n-rolled!

http://dl.dropbox.com/u/11178619/New%20Preamps/BF_DRUM1.mp3
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 03, 2013, 01:01:17 PM
That is some crazy stuff  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 03, 2013, 01:21:17 PM
sux, I know but I'm rusty as a fish hook... I used the Hotline2 cab simulator. Might not sound like all that and a bag o chips but I think it kills and you can dial in all kinds of different cab sounds!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 03, 2013, 01:23:43 PM
I thought it sounded good
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on April 03, 2013, 06:39:18 PM
Ok, totally off topic... ::)  Anybody ever try the EMG active circuit?? Like either of the two on this link?
http://revolutiondeux.blogspot.com/2012/06/active-pickups-how-do-emg-do-it.html

I want to mod my el cheapo' 7 string stock pickups but wondering if it's a waste of time?
I did. It balances highs, lows and mids nicely. The sound never turns to mud, even at lower tuning ( drop a# on my 6 string sg, dean markley strings 0.10-0.46 ).  And it's not buzzing like a mosquito. I did this with my old ibanez v8. My guess is that it may sound better with a better pickup. Ps i'used the first schematic, not the pcb by bajaman or the other schem that uses tl061. Only modification that I did was 2 165k resistors instead of 137k's. You should give it a go. Since the parts are so cheap and easy to find.

Cool... I am gonna make a couple then! So, you used the LM4250, right?

Hey Jokerx - I've made three of these. Two on vero and one using Bajaman's etch layout. All with great success and, yes, using the LM4250.

Vero here ----> http://www.paulinthelab.com/2012/04/emg-active-preamp-for-8185-pickups.html#comment-form
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on April 03, 2013, 06:51:52 PM
A "tightness" pot sounds great, and no gate on this one?

No gate, but you can add it in if you want...I would be inclined to put it in if it were foot switchable but I really don't want another footswitch... Unless I build it into a 1590DD? But, I really want to add a clean channel! That's one thing a lot of these preamps lack is a clean channel and they just have true bypass. I don't really like that... It's good for home/studio/recording applications but not so good for live..

I rigged up a switch that allows me to switch from Clean (into the normal input of my amp) and Dirty (via the Soldano S1 I built with it's output straight into the fx return and into the power amp)

If you're interested, I'll sketch it up and post it.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 03, 2013, 07:25:16 PM
A "tightness" pot sounds great, and no gate on this one?

No gate, but you can add it in if you want...I would be inclined to put it in if it were foot switchable but I really don't want another footswitch... Unless I build it into a 1590DD? But, I really want to add a clean channel! That's one thing a lot of these preamps lack is a clean channel and they just have true bypass. I don't really like that... It's good for home/studio/recording applications but not so good for live..

I rigged up a switch that allows me to switch from Clean (into the normal input of my amp) and Dirty (via the Soldano S1 I built with it's output straight into the fx return and into the power amp)

If you're interested, I'll sketch it up and post it.

Um.... YES! And while you're at it how bout the schema you used for the S1 or even the layout??  ;D

Start sketchin!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on April 04, 2013, 11:12:50 AM
The S1 I built is this one --->  http://tagboardeffects.blogspot.co.uk/2012/04/amt-s1-legend.html

Pix here ----->  http://imgur.com/a/qw342

I had to add drain presets to each J201, but it worked. Having used it for a while, I'd like a wee bit more gain out of it, so I'll experiment swapping out transistors.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on April 04, 2013, 11:17:39 AM
My preamp switcher alternates between my amplifier preamp (as normal) and my S1 clone straight into the fx return.
I've wired it so that "input" pedals and "fx-loop" pedals stay in circuit, like this....
(http://i.imgur.com/jgkY46G.jpg)

Here's the switch wiring
(http://i.imgur.com/XA9Atry.jpg)

The two circuits
(http://i.imgur.com/xuENmM7.jpg)

and it looks like this  :)

(http://i.imgur.com/jqQodmd.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on April 04, 2013, 02:24:22 PM
To get more gain you can try putting a 4.7 to 10 uF capacitor across the 1k source resistor of Q3.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: scuzzphut on April 04, 2013, 06:19:34 PM
To get more gain you can try putting a 4.7 to 10 uF capacitor across the 1k source resistor of Q3.

thanks jymaze - will give that a try  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on April 07, 2013, 11:20:31 AM
Yeah!!! The 1590B layout with on-board pots is done!!  8)
I completly changed the previous version for the BF4 this time. Thanks Jokerx for this project!
Please give me a couple of days to double check things and then post the layout.

I'm still fighting against the trimmers and a nice set of fets :icon_twisted: :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 07, 2013, 02:10:05 PM
Yeah!!! The 1590B layout with on-board pots is done!!  8)
I completly changed the previous version for the BF4 this time. Thanks Jokerx for this project!
Please give me a couple of days to double check things and then post the layout.

I'm still fighting against the trimmers and a nice set of fets :icon_twisted: :icon_twisted:

Cool Riccardo! I was hoping you would make a layout! By the way - We can still call it the Black Forest I just called it Blacker Forest for a goof...

Here's the latest schematic if you need it... Thanks to ggedamed! Again R22 and R5 are gonna have to be up to who ever builds it... I suggest to use a 100k trimmer to find the right values rather than swapping resistors, but that's just how I would do it...  R23 was added by ggedamed so the gain pot doesn't bottom out, which was a good idea! Another thing you can try is to put a switch on C2 so you can switch between 4.7uF and like say 470nF, it tightens up the low end... It doesn't have to be 470nF, I just used that as an example but 470nF did sound good on mine, again up to the person building it... This is it folks, this thing works!!! :icon_twisted: :icon_twisted: :icon_twisted: So, go build it! :icon_wink:
(http://dl.dropbox.com/u/11178619/New%20Preamps/blacker_forest_bf4_4-stages_sch.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: ggedamed on April 07, 2013, 03:19:40 PM
LOL, Jim, I took the name and R23 from your layout:

(http://dl.dropbox.com/u/11178619/New%20Preamps/Blacker%20Forest%20-%20On-board%20Pots%20Small.png)

Look in the top-left corner and you'll see a 10k resistor between pin 1 of the GAIN pot and ground. I'm not using a minimum gain limit resistor in my pedals because I want the full clipping range for all guitars, including ones with hotter pickups.

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 07, 2013, 03:46:58 PM
LOL, Jim, I took the name and R23 from your layout:


Look in the top-left corner and you'll see a 10k resistor between pin 1 of the GAIN pot and ground. I'm not using a minimum gain limit resistor in my pedals because I want the full clipping range for all guitars, including ones with hotter pickups.



oops... I forgot bout that lol... Great job anyway! :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 07, 2013, 05:40:02 PM
As far as E3 goes, can i use two 22k ohms instead of 24k ohms?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 07, 2013, 06:14:34 PM
As far as E3 goes, can i use two 22k ohms instead of 24k ohms?

If you are referring to R23 and R24 you could go up or down a couple of k and should be ok...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 07, 2013, 06:18:14 PM
Thnx mate. Cheers.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 08, 2013, 08:37:38 AM
Ok. Build report.
E3 zero noise. First I've tried it with my epiphone sg, active emg81 circuitry with ibanez v8 pickup. Zero noise, balanced highs, balanced mids and starved bass ... no matter what i did there was zero, or almost no bass. And my tuning is drop A#. And i hated it. Than I've plugged my other axe. Yamaha pac 120s, with passive jackson pickups. Love it!!! Fantastic sound, and again zero noise. And let me tell you thins thing is in my test rig, not in the box. And no shielded cables. There were two things that I've changed. Frist is 4n7 cap that is conected to gain pot. I;ve run out of 4.7n caps so i've placed 6.8. And those two 24k resistors became 22k resistors. That's it. Zero noise, hum or anything. Trimmed it to 4.5v and it kicks ass with yamaha made of agathis and other low quality woods and sounds like crap with epiphone made of mahogany:(. Maybe it's because of active pickup. Maybe that emg 81 circuitry would work better with some other pickup. I'll experiment and post the results here.

Oh yeah, ive used it as distortion box. Not as preamp. Direct into clean channel of my amp. PS ether I;ve @#$%ed up or this thing needs a bit more volume. It's not loud enough.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 08, 2013, 09:41:17 AM
Can this thing be used as preamp for one of those TDA power amps?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 08, 2013, 10:50:34 AM
Can this thing be used as preamp for one of those TDA power amps?

I believe Jim's intention is for these to be preamps in front of power amps/return jack of your amps or direct into consoles. But like his sig says, if it sounds good, then it IS good.
Thanks for the build report on the Engl. I haven't recieved my parts for the Engl yet but have built the Black Forest and it rips with emg 81's! And it sounds much better through the return jack rather than the input of my amps. Into a solid state power amp.... even tighter!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 08, 2013, 02:19:00 PM
4 fets version or the one before? And have you used his layout?

E3 is cool, but lacks bass. It's trebley as @#$%.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 08, 2013, 02:38:13 PM
Did you try it in the effects loop return? I know my BF is totally different sounding in front of the amp as opposed to the FX loop. I built the 5 fet version, I believe V4.1 and yes, all of the versions I have built have been JOK3RX's layouts all the way back to V1.
It sounds killer but does have some noise even with the shielded wire. I will build the 4 fet version next followed by the Engl, and based on what Jim said about the new 4 fet version, it sounds just as good as the 5 fet version without the noise.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 08, 2013, 02:54:42 PM
OMG ... The last cap ... i;ve placed 470p instead of 470n ... That's what's causing that treble. I lll replace little @#$%er and than Ill post a new report.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 08, 2013, 03:35:28 PM
Much better. And volume is ok, but now i have noise. Not epic, but it's there. It sounds great with SG. I think it will go in the box without noise gate.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 08, 2013, 05:22:50 PM
My Black Forest lost a TON of noise when boxed up. I would bet your Engl will be silent when it's finished.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 08, 2013, 06:52:23 PM
Seems like some different outcomes here...? I don't have a problem with my E3 other than the slight noise when I roll the volume pot back... no problems with the bass at all. Might double check all your values and connections, traces etc... Also, don't forget there is a jumper that goes from the bass pot to the sweep pot, very hard to see in the picture, it's yellow and spans across under the edge of the mid and treble pots about 1 inch long.

Miša - What version of the BF did you build?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 09, 2013, 07:04:01 AM
Can this thing be used as preamp for one of those TDA power amps?


YES!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 09, 2013, 07:55:12 AM
Seems like some different outcomes here...? I don't have a problem with my E3 other than the slight noise when I roll the volume pot back... no problems with the bass at all. Might double check all your values and connections, traces etc... Also, don't forget there is a jumper that goes from the bass pot to the sweep pot, very hard to see in the picture, it's yellow and spans across under the edge of the mid and treble pots about 1 inch long.

Miša - What version of the BF did you build?
E3 :D

Yep jumper is there, It's got bass, but not as much as i would like :)
It's great for black metal though.

This E3 is going my preamp box. 2 Dirt channels and 1 clean. Just to decide which one is going to be second dirt channel :)

I'm about to build BF 4 fet version. But you haven't verified that layout.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 09, 2013, 09:16:02 AM
My parts are on the way so if you don't verify it, I will. Unless someone else beats us to it  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 09, 2013, 10:23:56 AM
:). Tonight i'll etch BF 4 fet version pcb. I think I have most of the parts, if not all of them, on my table. I would love to use it as a second dirt channel on my preamp. That would be cool as @#$%. And to use zendrive as booster for solos.  :icon_eek:
I've got a boner just thinking about it  :D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 09, 2013, 11:14:48 AM
Muhahaha! Ask Jim for his cab sim and you can add that in there too!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 09, 2013, 12:02:33 PM
I've etched hotline 2 allready. But I won't use it in this project. But Sonic maximazer will be included :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 09, 2013, 12:10:36 PM
I'd like to see your final product Miša, it sounds very cool  :icon_cool:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 09, 2013, 12:37:42 PM
The general idea came from the fact that the place where me and my band mates play doesn;t have another guitar amp. Just one for guitar and another for bass, and we have no bass player. I've plugged my guitar in a bass amp, in a mixer and god knows where. So i've talked to the owner of the place, a night club to be precise ( he has lent us his club for rehearsals during the day, for free, which is very cool ). I've told him that i could make one 100w amp ( one of those tda based amps ) with 2 dirty channels and 1 clean, but he will have to buy box for it. And he is up for it. But first i'll have to convince him so I've made tda based 20w power amp and ever since i've been looking for cool preamps for it. E3 is great engl fireball simulation. Fantastic. I've been thinking about ether using Jim's BF 4 fet version ( if he is cool with that ), or Old Mike's krankenstein for a second dirt channel. This is a drawing of my idea. Reason for DPDT's is simple, they are really expensive in my country. 10 euros per piece ...

(http://i1249.photobucket.com/albums/hh505/JebemMajke/Preampdrawing_zps488f5c14.png)


Ps Jim, have you tried Mike's krankenstein? Do you have a pcb layout for it?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 09, 2013, 03:23:03 PM
I @#$%in love E3!! I've played deep purple and aker%^&*e without even moving the drive knob. I did all the tweaking with vol pot on my guitar and pickup split switch.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 09, 2013, 03:31:21 PM
Ok, enough about the E3! This isn't fair, my parts are not here yet!!  :'(
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 10, 2013, 08:25:38 AM
2sk117 as Q1 is way better choice. For me at least. Little bit more gain, but it's not as "fuzzy" as j201.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 10, 2013, 09:55:05 AM
I used a 2n5457 for my BF to cut down on the "fizz" factor. I just got in a few K30A-R's I'm gonna try also... the tighter the better!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 10, 2013, 11:02:29 AM
I am not sure if we are talking about the E3 or the BF or what version of the BF?

I think Miša is talking about the E3 and pakrat is talking about the BF although, I am not sure which version of the BF?? :icon_confused:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 10, 2013, 11:22:58 AM
Miša is talking about the E3, I was talking about the BF 5 stage. We are both talking about the "fuzz" generated by J201's  :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 10, 2013, 11:41:09 AM
Hey Jim. E3 is what I'm talking about. Have you tried Fet/Mosfet Krankenstein?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 10, 2013, 11:55:15 AM
Hey Jim. E3 is what I'm talking about. Have you tried Fet/Mosfet Krankenstein?

Yup! You want the layout and transfer?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 10, 2013, 12:08:30 PM
Of course he does... sheesh  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 10, 2013, 12:11:59 PM
Miša / Frank

Check yer email...  :P
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 10, 2013, 12:43:21 PM
 :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 10, 2013, 12:51:44 PM
Wow, man. Thanks. You are the man!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 10, 2013, 03:19:55 PM
I have to ask, is it a monster like E3?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 10, 2013, 04:13:59 PM
I have to ask, is it a monster like E3?

look at it... very similar, so.... take a wild guess :icon_twisted:

So, I have to ask... does the E3 have a lot of TIGHT@SS high gain? How does it compare to let's say... the Dr.Boogie?

By the way, you can mod the tone stack to get more bass response... :icon_wink:  

All of these Russian preamps with the 2N7000's are bad to the tone bone!!! Not at all happy with the Russian version of the Uberschall...  :P
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 10, 2013, 05:59:00 PM
I must say that I've never made myself a dr boogie pedal. I was never a fan of mesa. Engl, Framus, Krank ... that's my metal :)
But I'll give it a go.

I did make framus cobra ( fet version/conversion ) and it was out of this world. But the noise was too unbearable. So I took it apart. 2sk117's were the fets I've used in that project.

Back to the E3

It's high gain as @#$%. Black metal, death metal, thrash ... it fits all those extreme metal genres. And with vol pot ( guitar's vol pot :) ) down you go to the Judas Priest, Deep Purple territory.
It doesn't like my zendrive clone ... too much noise when I try to push it with zen ...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 10, 2013, 06:15:08 PM
In my opinion, the Dr boogie is a great high gain pedal that does actually capture the flavor of the Rectifier but....... like Miša, I'm not a big fan of the Mesa crunch. It's too loose and spongy for me. I've never had the pleasure of playing a real Engl OR a Krank, but I did play an Uberschall and it was pretty nice. Still.... nothing can beat my good old Rg100!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 11, 2013, 12:08:56 AM
In my opinion, the Dr boogie is a great high gain pedal that does actually capture the flavor of the Rectifier but....... like Miša, I'm not a big fan of the Mesa crunch. It's too loose and spongy for me. I've never had the pleasure of playing a real Engl OR a Krank, but I did play an Uberschall and it was pretty nice. Still.... nothing can beat my good old Rg100!!

Way back in the 80's and 90's I owned all kinds of Mesa Boogies and I didn't like any of them... I couldn't figure out why people liked them so much, like you said they has a loose attack and spongy feel to them... There weren't all of these amps and preamps available like there are today and digital really sounded digital! I went through the tube amp phase then the tube preamp phase / solid state power amp phase then back to the tube power amp then to all digital then back to the tube amp / head etc... on and on in vicious cycles in search of THE RIG with THE SOUND... The closest I have ever gotten to having a sound that I was totally happy with was 2 Hughes & Kettner Metal Shredder tube preamps running into a MosValve 500 power amp, 250 watts per channel stereo into four 4x12 cabs. I had some digital midi controlled effects in between, mostly delay, chorus, reverb and nothing else.... and of course a TS808 sitting in front of it all. You wanna talk about loud and brutal!!! Most of the time if we played clubs/bars they didn't even have to mic my guitar, at all! Was sick I tell ya :icon_twisted: To this very day I still have not been able to reproduce that sound even on a small level let alone a large rocket engine level..! Anyway, those good old days are long gone and now I just play around the house after work late at night so, the "nuclear assault bunker buster" guitar rig might not go over so well  :icon_lol: The key to that rig was the massive power and headroom it had coupled with the H&K preamps! I think these jfet preamps would maybe sound even better in the same setup... These really weren't around much if any back then and if there were any they had not reached a level of tone that they have today. I got to where I hate power tubes! They are just so inconsistent, they start to get old, they are horribly moody depending on the room temp, humidity, where they are located, if you move your rig etc bla bla bla... They sound great one day after being warmed up for about 2 hours and then they sound totally different the next day etc... They sometimes get weird harmonic interference, squeal like a pig and the list goes on... I hate'em! Preamp tubes are a totally different story, I love them!

Now, the Dr.Boogie (to me anyway) sounds nothing like a Mesa Boogie Dual Rectifier.. at all! But, it does sound good and has sort of a Boogie sound to it... I like it but it needs something, can't quite put my finger on it but it lacks character and tone in a way? Somewhere in the process of fine tuning and tweaking it lost it's magic, maybe? You can get a killer sound with it if you process it and enhance it but it is missing something and it's not because it uses jfets, it's something else...? I have 3 of them right now so I ain't knocking them at all, they do have a very distinctive sound and are very well refined, no bugs etc..  just my take on it.   
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 11, 2013, 12:38:16 AM
I agree with everything you said, except that a Dr boogey doesn't sound like a Rec at all? I have a Rec and a Dr boogie, and of course the first thing I did when I built the Dr was to A/B it with the real deal. While it does not sound exactly like a Rec, it does contain it's flavor for sure.... and it's shortcomings. Again, as we all know, or should know....  tone is in the ears of the beholder. 
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 11, 2013, 12:53:57 AM
Ok, first off... What is it with guys named Sergey??? Are they all bad@sses?

Now, let me start by saying that I owned the SS-30 and I could not get this sound! It sounded great but I could not get THIS SOUND... I even went so far as to match the knob setting from this video and not even close... There are many factors in play here! Number 1. My name isn't Sergey and that is probably the biggest factor! :icon_lol: Number 2. I don't have a Tube Cake power amp running into a custom cab with some weird hairless egyptian looking sphinx cat sitting on top with a SM57 perfectly placed running into some totally magically tweaked DAW, and wood floors, of course... Number 3. I don't own a $5000.00 Suhr custom guitar which is irrelevant at this point since my name is not Sergey... Are you getting what I am trying to say here?? :icon_lol:

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 11, 2013, 01:04:54 AM
Wow.... friggin crazy!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 11, 2013, 01:54:06 AM
Did somebody say variac?  :icon_mrgreen:

Must have been the high gain voices in my head :icon_twisted:

Not to get yer hopes up but if this works it will open up a can of high gain whoop@ss!!! :icon_twisted:

Don't worry... daughter board is coming
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: hari on April 11, 2013, 04:16:18 AM
my second post for this threat

I already etched Blacker Forest 4 stages PCB, and I have few questions:

1. can I use 2k2 instead of 2k4 ?
2. Any relpacement for bat85 ?
3 Wide mean another switch (DPDT) ?

I hope it can beat Metalzone  :D

best regard
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 11, 2013, 04:29:35 AM
Bat 41, 42, 43, 45.

Come on verify layout so that i can start making that thing as well :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on April 11, 2013, 09:02:52 AM
2.2 instead of 2.4k should not hurt too much as it is barely a 10% deviation.

Any schottky will work there, and I am sure it would sound good without the schottky too.

For the layout verification... I am sure if you sit 5 to 10 minutes with the layout on your left and the schematic on your right you can verify it. It is a very clear and linearly oriented layout so it is easy to verify.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 11, 2013, 09:26:56 AM
my second post for this threat

I already etched Blacker Forest 4 stages PCB, and I have few questions:

1. can I use 2k2 instead of 2k4 ?
2. Any relpacement for bat85 ?
3 Wide mean another switch (DPDT) ?

I hope it can beat Metalzone  :D

best regard


1. can I use 2k2 instead of 2k4 ? - Yes
2. Any relpacement for bat85 ? - probably just about any schottky diodes will work
3 Wide mean another switch (DPDT) ? - optional...

jymaze - already explained...

beat Metalzone?? FYI - This is a preamp
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on April 11, 2013, 09:41:09 AM
Metal Zone is the noisiest thing out there (although i like that you can emulate it by using a chainsaw and a pitch pedal ;)), and it's so intense on the highs, The black forest beats it both as a pedal and as a preamp with miles.

Was gonna build the 4-stage right now, and realized i'm out of schottkys (well, i do have some HUGE ones, about the same size as 1n5408, but no.. Will wait a few days for new to arrive :P)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 11, 2013, 10:27:07 AM

Was gonna build the 4-stage right now, and realized i'm out of schottkys (well, i do have some HUGE ones, about the same size as 1n5408, but no.. Will wait a few days for new to arrive :P)

You can leave them out until they arrive... It will still work very well!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: caspercody on April 11, 2013, 02:54:07 PM
I have not played any these amps you are emulating, would any of them get close to that tone (in the video)? Either the BF, or ENGL.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 11, 2013, 03:06:16 PM
I have not played any these amps you are emulating, would any of them get close to that tone (in the video)? Either the BF, or ENGL.

I don't see why not... Same type design. ENGL might be the closest match. Remember, it's not just the preamp itself making that tone but the combination of the SS30 and the Tube Cake 3 watt power amp pedal... And it helps a lot if your name is Sergey! :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 12, 2013, 01:29:35 PM
So I've started BF 4 fet version and Krank at the same time and I lack some parts. 2.7k and 2.4k resistors to name a few :)
Both plates are on my working table waiting for parts ...
Also I've etched Dr boogie pcb, just to try it out. Maybe I'll like it, who knows.
Ps I think that I'll finish BF 4 fet, Krank, Zvex Box of metal and boogie at the same time. And I'll do a test with these pedals and MT-2. Just for the sake of fun.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 12, 2013, 03:46:55 PM
I too have the Krank and BF 4 fet boards etched. Still waiting on some caps though. Arrrgh I HATE waiting!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 12, 2013, 07:20:40 PM
Sh!t man, if I don't have the right value resistor I just find two in series that get it or close! Might not look as good but if I were in it to win a beauty contest I would never get anything built...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 13, 2013, 06:30:38 AM
Well i do the same in most cases. But i also need some electro's and 22n's and some pots.

Any way i've etched madbeans chunk chunk board ( boogie ) and already I;ve decided to remove presence pot. I'm not sure that I'll need it. My guess is that I just ignore holes for that pot and the cap?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 13, 2013, 07:47:12 AM
Well i do the same in most cases. But i also need some electro's and 22n's and some pots.

Any way i've etched madbeans chunk chunk board ( boogie ) and already I;ve decided to remove presence pot. I'm not sure that I'll need it. My guess is that I just ignore holes for that pot and the cap?

I am always in need of some pots... :icon_rolleyes:

Yeah, you can just leave the presence off of the chunk chunk... you can leave the cap in or take it out makes no difference since the pot sends it to ground and if not there then no connection to ground... will work either way.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on April 15, 2013, 05:10:10 PM
Blacker Forest 4 gain stages

Build doc:
http://db.tt/Sr6COBTg (http://db.tt/Sr6COBTg)

Pics:
http://i875.photobucket.com/albums/ab315/Cap_87/IMG096.jpg (http://i875.photobucket.com/albums/ab315/Cap_87/IMG096.jpg)
http://i875.photobucket.com/albums/ab315/Cap_87/IMG095.jpg (http://i875.photobucket.com/albums/ab315/Cap_87/IMG095.jpg)

There are two different sets of pot values of the tonestack..Jim?? Layout it's the same anyway
Feel free to ask questions or pm me ;)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 15, 2013, 05:21:46 PM
Outstanding Cap, great job. How does it sound?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 15, 2013, 05:39:29 PM
Nice one Cap. Say, what's the size of that layout of yours.

PS
Build report
Finished BF 4 fet
Wow. Really nice, really chunky. I'll try 2sk117's tomorrow. J201's do tend to turn fet distortions into big muff :)
It's way different than E3, but that's a good thing :D. Pardon my French, but this one sounds bassy and low as @#$% :D, which is great. Great build, really recommended. Jim great job on this one. And i haven't even placed that eq sw. Haven't tried a bogner, but this thing ripps.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 15, 2013, 05:44:02 PM
That's great to hear Miša, I'm still waiting on some stuff to arrive while my unpopulated boards laugh at me  :icon_rolleyes:   Have you built the Krank yet? I have that one waiting as well..... it's gonna be a marathon of building this weekend.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 15, 2013, 05:54:18 PM
I'll start building krankenstein in a minute. I've been busy debugging bbe sonic stomp.

So, BF 4 fet done, E3 done, Zvex Box Of Metal almost done ( waiting for pots ). Krankenstein and dr boogie are next :D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 15, 2013, 06:02:56 PM
That's a lot of gain coming from your house.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 15, 2013, 07:14:52 PM
Blacker Forest 4 gain stages

Build doc:
http://db.tt/Sr6COBTg (http://db.tt/Sr6COBTg)

Pics:
http://i875.photobucket.com/albums/ab315/Cap_87/IMG096.jpg (http://i875.photobucket.com/albums/ab315/Cap_87/IMG096.jpg)
http://i875.photobucket.com/albums/ab315/Cap_87/IMG095.jpg (http://i875.photobucket.com/albums/ab315/Cap_87/IMG095.jpg)

There are two different sets of pot values of the tonestack..Jim?? Layout it's the same anyway
Feel free to ask questions or pm me ;)

That looks great Riccardo!!! In looking back at the schematic I have found a mistake... ggedamed created the schematic so you can kick his @ss  :icon_lol: Just joking about the butt kicking of course!! I really appreciate him drawing that schematic so maybe some @ss kissing would be in better order since I hate drawing schematics! Anyway, R17 - 22k is not needed so you can leave it out. If you look closely you will see that it is parallel with R16 that is also 22k which will give you around 11k at the source... It will work like this and might not sound bad at 11k but why have 2 resistors if not needed... honest mistake :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 15, 2013, 07:21:16 PM
So that jumper that's connecting voice and 22k in that layout of yours ( talking to Jim ) is not necessary. In fact it shouldn't be there?

Edit

Wire must be there in order for that fet to be connected to voice. Sto the other 22k, from voice to the ground should be lifted?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 15, 2013, 07:49:51 PM
So that jumper that's connecting voice and 22k in that layout of yours ( talking to Jim ) is not necessary. In fact it shouldn't be there?

Edit

Wire must be there in order for that fet to be connected to voice. Sto the other 22k, from voice to the ground should be lifted?

Miša,

You are correct, good catch! That was a carry over from me using another layout for template to make this one... So, it's my mistake :icon_redface: remove the 22k behind the volume pot to ground on my layout... Ok, now you guys can commence in kicking my @ass now  :icon_mrgreen:

On Riccardo's layout you can remove either one from what I can see, should be the same..

~ Jim
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 15, 2013, 08:11:38 PM
There are two different sets of pot values of the tonestack..Jim?? Layout it's the same anyway
Feel free to ask questions or pm me ;)

Yes the values differ but they don't make that much of a difference especially with the voice pot installed. Originally the treble pot on the real tube Uberschall is 250k and I thought the treble went way too high for me anyway so I lowered it to 100k and the bass on the original tube preamp is 1M and I noticed that after turning the bass past the half way mark there was no noticeable difference in the bass so I changed it to 500k... This was all before I started using the "sweep/voice pot" which causes the tone stack to change into almost a completely different tone stacks... It's kinda like having a variety of different tone stacks and that coupled with the "Wide switch" gives you a large array of tone combinations... So, you can get really scooped mids or really heavy mids and it effects the treble and bass as well... So, I guess what I am saying is the values are not that critical as with a straight old Marshall type tone stack... I would experiment with different values on the voice pot as it creates huge differences in tone and the way the other pots react...  On the Krank schematic it is called the "Sweep pot" and it's 200k :icon_eek: to me that is kinda too much but whatever floats your boat...

The way the voice/sweep pot works is you adjust it then make changes to your treble, mids and bass, it gives them different range. If you turn it by itself and don't adjust the other pots it just scoops or boosts the mids and treble mainly and you will be like that's kinda ok but don't stop there, turn the other knobs to get the idea... Also, the wide switch really opens up the sound and really does give it a wider brighter sound!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 16, 2013, 04:30:38 AM
There is always gain xD. Even at gain pot turned to 1 there is gain :D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 16, 2013, 04:36:05 AM
There is always gain xD. Even at gain pot turned to 1 there is gain :D


?? Black Forest

Leave out R23 and add jumper...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Somicide on April 16, 2013, 05:12:00 AM
Blacker Forest 4 gain stages

Build doc:
http://db.tt/Sr6COBTg (http://db.tt/Sr6COBTg)

Pics:
http://i875.photobucket.com/albums/ab315/Cap_87/IMG096.jpg (http://i875.photobucket.com/albums/ab315/Cap_87/IMG096.jpg)
http://i875.photobucket.com/albums/ab315/Cap_87/IMG095.jpg (http://i875.photobucket.com/albums/ab315/Cap_87/IMG095.jpg)

There are two different sets of pot values of the tonestack..Jim?? Layout it's the same anyway
Feel free to ask questions or pm me ;)
I was just about to request something like this!  The wife is requesting guitar lessons and is a -huge- metal fan; building her a tiny giant with this as a second channel, she loved your clip with drums, jim  :icon_twisted:

God, I love this woman! ;D

(why is there no :icon_headbang: emoticon?  lol)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 16, 2013, 05:32:04 AM
There is always gain xD. Even at gain pot turned to 1 there is gain :D


?? Black Forest

Leave out R23 and add jumper...

Nah, I'll leave it the for now.
2sk117 didn't work here. I've re biased fets ... and checked the twice and there was no sound. Ps I'm aware that it has way different pinout :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 16, 2013, 05:39:28 AM
There is always gain xD. Even at gain pot turned to 1 there is gain :D


?? Black Forest

Leave out R23 and add jumper...

Nah, I'll leave it the for now.
2sk117 didn't work here. I've re biased fets ... and checked the twice and there was no sound. Ps I'm aware that it has way different pinout :)

Um.... I think you uncovered yet another mistake made by yours truly :icon_redface: Maybe gain pot should be 100k/A...ya think?  :icon_mrgreen:

By the way, J201's are working great for me! Way more than enough gain and very little noise... no hum at all!

Sorry for the stupid mistakes people! Very little sleep does funny things... :P
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 16, 2013, 07:48:32 AM
Yeah. there is almost no difference between 11 o clock and max :D. So 100k would suffice.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on April 16, 2013, 01:08:40 PM
Suppressing a stage, then paring down the gain pot... I always told you that thing had too much gain!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 16, 2013, 01:23:09 PM
Someone asked so here is my answer.
This thing eats MT-2 for breakfast. With the amount of gain, dynamics and the overall inability to become a buzzing mosquito, which is the biggest turn of in a MT-2. Seriously build bf 4 fet version and you won't be disappointed. E3 has less gain than bf 4 fet, but has more definition and clarity. But bf4 fet has more bass which is always cool as @#$%  :icon_cool:. I swear to much ...  :-X
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 16, 2013, 07:18:30 PM
Suppressing a stage, then paring down the gain pot... I always told you that thing had too much gain!!!

Um.... If I do recall, it was you who came up with the idea to turn the 5th jfet into an additional gain stage :icon_lol: It was in "the other forum" of course... let's say around the 2nd page 5 post up from the bottom.  ;)

Now it's actually back where I started on the very first BF, it came full circle. For some reason I don't remember getting this much gain in the beginning using the 4 gain stages... That's why I asked you how to get more gain out of it... remember?

I am just bustin yer chops man... You have been there since the very beginning and have been an invaluable help!!! Would probably not have made it this far without your help... And lately you have been saying to bring it down a notch... I did try it a while back when you first mentioned it but it sounded bad and had very little gain, but that board had been reworked so many times that it was shot to hell! I kept using it but finally gave up, trashed that board and took a break and worked on other stuff. Then I found a board that I etched a long time ago from my very first BF layout that I never used... populated it with the current parts and WOW!

Now we have Riccardo's kick@ass 1590b layout with on-board pots and my surfboard with on-board pots... 

I think this version is finally done pending a few minor value changes/corrections! I have encountered almost zero bugs with mine! Everybody agree?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on April 16, 2013, 07:41:54 PM
Hey Jok3rx,

I was just being annoying :icon_wink: don't take me seriously. It is a good circuit and you get to have full credit for that.

I am trying to finish my Petruccifier, but I am lagging and it is just there on my bench 2 solder points from being done... Fear of finishing/failure I think... So I started a 2x12 cab now... I will try to push myself to finish it this week though.

I did a simulation and there is about 15 dB in total gain difference between a 100k pot and a 1 meg pot. Fortunately the frequency response is not too affected, but still the 1 meg pot gets more bass in (potentially a tad less tight in real life?). There is still plenty of gain, about like the Seventheaven if I remember correctly.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: ggedamed on April 16, 2013, 08:57:53 PM
Ha! My ass is safe (again):

(http://s11.postimg.org/8qk5whbyr/2013_04_17_034520.png)

See the two white circled resistors? You also had two capacitors in paralell, so I thought, why not? The man likes things in paralell. Actually, spare time provided, I'll parallel some JFETs to lower the already low noise :icon_lol: (of course, I'm talking of my pedal, which is not too different from your BF 4 stages, more like a BF 3 stages).

Miša, 2SK117 is smokin'. Sure, it has a different pinout and you have to rebias, but it has (much) lower noise and (much) higher transconductance. My batch of 2SK117 and 2SK170 have Vp around 0.45-0.55V, so it's not fit for the first stage as is, especially if you have hot/active pickups. But, one can always bias it through a voltage divider instead of self-bias.

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 16, 2013, 09:43:06 PM
Ha! My ass is safe (again):

(http://s11.postimg.org/8qk5whbyr/2013_04_17_034520.png)

See the two white circled resistors? You also had two capacitors in paralell, so I thought, why not? The man likes things in paralell. Actually, spare time provided, I'll parallel some JFETs to lower the already low noise :icon_lol: (of course, I'm talking of my pedal, which is not too different from your BF 4 stages, more like a BF 3 stages).

Miša, 2SK117 is smokin'. Sure, it has a different pinout and you have to rebias, but it has (much) lower noise and (much) higher transconductance. My batch of 2SK117 and 2SK170 have Vp around 0.45-0.55V, so it's not fit for the first stage as is, especially if you have hot/active pickups. But, one can always bias it through a voltage divider instead of self-bias.



Yup thanks... Miša already pointed the resistors out earlier, that was a mistake I made from using the same layout from another board (E3) and modified for this... It was overlooked, by me. Just leave  one of them out, maybe the one behind the vol pot..but doesn't matter. The parallel caps are just the way the schematics for the Bogner Uberschall had them... of course you could replace with one cap of the combined value if you have any caps of those odd values... I left them in like that cause I didn't want to lose any Bogner MOJO magic :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 16, 2013, 10:23:39 PM
Hey Jok3rx,

I was just being annoying :icon_wink: don't take me seriously. It is a good circuit and you get to have full credit for that.

I am trying to finish my Petruccifier, but I am lagging and it is just there on my bench 2 solder points from being done... Fear of finishing/failure I think... So I started a 2x12 cab now... I will try to push myself to finish it this week though.

I did a simulation and there is about 15 dB in total gain difference between a 100k pot and a 1 meg pot. Fortunately the frequency response is not too affected, but still the 1 meg pot gets more bass in (potentially a tad less tight in real life?). There is still plenty of gain, about like the Seventheaven if I remember correctly.

ha ha...  :icon_lol: Well, I would give Reinhold Bogner full credit for this circuit! I am a wanna be circuit copying solder monkey, nothing more...  ;D

Now unveil this Petruccifier you have been blowing your wad on, damn-it!! :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 16, 2013, 11:00:23 PM
Ok, so I think this is final for the Black Forest "standard version"...?

One of the 22k resistors in parallel on the 5th jfet from source to ground - remove. Agreed
Gain pot corrected to 100k/A Agreed

These are debatable but I have tested and they work either way.
Treble pot - 100k/B
Bass pot - 500k/B
Mid pot - 10k/A or 20k/A... not much difference that I can tell.
Voice pot - 50k/B but can be as high as 150k/B... I prefer 100k/B

Boost resistor - not sure, find your preference... Recommended - use a trim pot to find "your value" then replace with fixed resistor of same value.

I miss anything?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Somicide on April 17, 2013, 03:01:12 AM
So... Have you made it final yet?  I'm dying to get started here, but want to wait til it's as final as possible before getting started.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 17, 2013, 03:26:12 AM
Ok, so I think this is final for the Black Forest "standard version"...?

One of the 22k resistors in parallel on the 5th jfet from source to ground - remove. Agreed
Gain pot corrected to 100k/A Agreed

These are debatable but I have tested and they work either way.
Treble pot - 100k/B
Bass pot - 500k/B
Mid pot - 10k/A or 20k/A... not much difference that I can tell.
Voice pot - 50k/B but can be as high as 150k/B... I prefer 100k/B

Boost resistor - not sure, find your preference... Recommended - use a trim pot to find "your value" then replace with fixed resistor of same value.

I miss anything?
I would go 1M c pot. For gain. Because I like that extra bassiness in gain. And my advice is to lower that 10k resistor that's between gain pot and ground. 2.2k should suffice. Or even 1k. As far as boost resistor goes ... It becomes a little less muddy. And a bit more "overdrivey". Which is cool. But not really a must. Bass pot could go 1M or 500k. Your choice. I like 1M. For mid pot ... well most of the times I just leave it at max :D. So 20k for me.
Voice is really useful. More useful than sweep in E3.

Vol pot should be 1M a pot.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 17, 2013, 07:42:29 AM


I would go 1M c pot. For gain. Because I like that extra bassiness in gain. And my advice is to lower that 10k resistor that's between gain pot and ground. 2.2k should suffice. Or even 1k. As far as boost resistor goes ... It becomes a little less muddy. And a bit more "overdrivey". Which is cool. But not really a must. Bass pot could go 1M or 500k. Your choice. I like 1M. For mid pot ... well most of the times I just leave it at max :D. So 20k for me.
Voice is really useful. More useful than sweep in E3.

Vol pot should be 1M a pot.

ok, mine has plenty of bass and gain either way so don't know bout the 1M/C pot for gain and I don't have one to try..? would like to keep it standardized as much as possible... Everybody is gonna have different guitars with different pickups, some active hot pickups, some hot passive, some not so hot passive, some with a lot of bass or treble etc... so 100k/A is good in my opinion and people can try others if they like..

Agreed on the resistor that's between the gain pot and ground... It should probably be 1k like you said or maybe just a jumper? I only had it there so when you turn the gain all the way down it wouldn't turn the signal completely off... This is optional

Boost is also optional... I like to use one resistor to give it a little less gain (like a crunch channel) and a boost resistor to give it more gain (like a lead channel) but if you really wanted you can find the resistor that gives it the max amount of gain (without getting noisy/muddy) and just use the volume pot on your guitar to get the crunch sound... So, it is optional... don't use it and save yourself a switch  :icon_wink:

Voice/Sweep is useful and affects the characteristics of the tone stack making the value of some of the pots like treble and mids not so critical... and the Wide switch does even more... So the treble can be anywhere from 100k to 250k and the mids can be anywhere from 10k to 25k.. just my opinion.. But to keep them somewhat standardized for a wide array of players and different guitars etc I would use 100k for treble and 10k for mids and 500k for bass.

Agreed - Volume should be 1M

Trying to get this to a "standard" setup.. You will see why, shortly!  :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 17, 2013, 09:09:01 AM
(https://dl.dropboxusercontent.com/u/11178619/New%20Preamps/BF5%20-%20S.png)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 17, 2013, 09:53:29 AM


I would go 1M c pot. For gain. Because I like that extra bassiness in gain. And my advice is to lower that 10k resistor that's between gain pot and ground. 2.2k should suffice. Or even 1k. As far as boost resistor goes ... It becomes a little less muddy. And a bit more "overdrivey". Which is cool. But not really a must. Bass pot could go 1M or 500k. Your choice. I like 1M. For mid pot ... well most of the times I just leave it at max :D. So 20k for me.
Voice is really useful. More useful than sweep in E3.

Vol pot should be 1M a pot.

ok, mine has plenty of bass and gain either way so don't know bout the 1M/C pot for gain and I don't have one to try..? would like to keep it standardized as much as possible... Everybody is gonna have different guitars with different pickups, some active hot pickups, some hot passive, some not so hot passive, some with a lot of bass or treble etc... so 100k/A is good in my opinion and people can try others if they like..

Agreed on the resistor that's between the gain pot and ground... It should probably be 1k like you said or maybe just a jumper? I only had it there so when you turn the gain all the way down it wouldn't turn the signal completely off... This is optional

Boost is also optional... I like to use one resistor to give it a little less gain (like a crunch channel) and a boost resistor to give it more gain (like a lead channel) but if you really wanted you can find the resistor that gives it the max amount of gain (without getting noisy/muddy) and just use the volume pot on your guitar to get the crunch sound... So, it is optional... don't use it and save yourself a switch  :icon_wink:

Voice/Sweep is useful and affects the characteristics of the tone stack making the value of some of the pots like treble and mids not so critical... and the Wide switch does even more... So the treble can be anywhere from 100k to 250k and the mids can be anywhere from 10k to 25k.. just my opinion.. But to keep them somewhat standardized for a wide array of players and different guitars etc I would use 100k for treble and 10k for mids and 500k for bass.

Agreed - Volume should be 1M

Trying to get this to a "standard" setup.. You will see why, shortly!  :icon_twisted:

Dont forget that it should be log. With lin you go from awfully quiet to "what the @#$%!!" loud somewhere between 10 and 11 o'clock.


1M C for gain because, most of the gain changes are somewhere between 25k and 100k. And the rest just ads a bit bass to the gain. But that's my opinion. Haven't tried wide sw yet :).
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 17, 2013, 10:06:15 AM
Ok, now for the Black Forest - No Return version :icon_twisted: Sorry... couldn't help myself :icon_lol: You should be able to add this to the previous version with very little modification... This is just optional folks... don't feel like the standard version isn't the latest because it is! This just adds a little fire :icon_twisted:

Ok, Volume is 1M/A... layout spec wrong. deal with it :icon_mrgreen:

(https://dl.dropboxusercontent.com/u/11178619/New%20Preamps/BF5-Variac.png)



(https://dl.dropboxusercontent.com/u/11178619/New%20Preamps/BF5-NR.png)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 17, 2013, 10:35:02 AM
50k trimmers eh? I couldn't find A20k right angle pot, will A25k be ok? Mmmmmmm.... variac...........
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on April 17, 2013, 10:50:57 AM
What is the point of that "variac" board (weird name for sure)? It looks like just another volume pot with another buffer after it to me. It is a class A buffer okay, but why would we need a class A buffer to transmit some massively distorted sound? Not sure what the point is in all respect.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 17, 2013, 10:52:42 AM
Jim said it adds a sort of tube warmth or saturation to it. Worth a try I'd say, it can always be removed.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on April 17, 2013, 12:45:45 PM
Ok, why not. I may recycle the idea to replace the Tillman preamp I have in one of my guitars. Problem is that it may eat batteries much quicker with a current draw equal to IDDS.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: ggedamed on April 17, 2013, 05:42:36 PM
Post-gain? Maybe a post-volume volume, buffered by a Hi-Fi/Viktor Kempf style buffer.
BTW, this is the article that made me start stalking Viktor Kempf (http://www.rusblues.ru/?menu_num=1&subm_num=4&cat_num=4&q=/node/26) and the other russian JFET sorcerers. Looking at his designs, it seems that he moved on since then.

To decrease the consumption you could add a resistor in the source (look at figure 4B in the above article). Or you can split that resistor in half and put one in each of the sources, like Erno Borbely did. But I'm pretty sure that other than the 2 FET mojo, this addon adds next to nothing to the sound. One can use this kind of follower to have no DC offset at the output or to drive low-impedance loads. But with a 10k load there's no difference whatsoever between this and a basic source follower, in a guitar pedal. If you'd want it to drive headphones, you'd use higher Idss JFETs.

Also R21's value of 1k on the schematic must be a typo. J201's maximum Idss is 1mA, so it cannot work there.

One important thing to understand about this circuit is that it is very much in the spirit of DIY.
I mean, you better use a breadboard, it's not really fit for series production.
Just build the first stage with whatever JFET you have at hand and you adjust it right. Replace the trimmer with an resistor. Listen to the output.
Than build the second gain stage in the same manner and adjust it. Replace the trimmer with an resistor.
Than connect the first stage to the second one through the gain pot and the surrounding circuitry. Listen to the output.
Than build, adjust and connect additional stages until you have enough distortion or noise (depending on which is more important to you). Replace the trimmers with resistors. Listen to the output.
Than add the tone stack and the final gain stage. Listen to the output.
At the end you'll have your very own one-of-a-kind distortion, the way you like it, made with whatever you had at hand and fit like a glove to your rig. And I promise you'll love it.



Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 18, 2013, 05:25:49 PM
Krankenstein done ... omg ... this one is a mother@#$%er ... gain is almost limitless :D. This one is the best so far. E3 and Krankenstein are going in the same box as my preamps and BF 4 fet is going to be tweaked a bit more, but it;s still a great pedal. Good design Jim.

BUT KRANKENSTEIN ROCKS!!!!! xD
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: hangingmonkey on April 18, 2013, 05:33:27 PM
Is r15 820 r or k?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 18, 2013, 07:14:46 PM
820r / 820ohm
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 18, 2013, 07:37:41 PM
Here's the latest layout for the Black Forest no add-ons, just the main board.. Only a few very minor corrections and the older board will work perfectly fine if you have already etched it.

https://dl.dropboxusercontent.com/u/11178619/New%20Preamps/BF5.pdf
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 18, 2013, 08:33:13 PM
Krankenstein done ... omg ... this one is a mother@#$%er ... gain is almost limitless :D. This one is the best so far. E3 and Krankenstein are going in the same box as my preamps and BF 4 fet is going to be tweaked a bit more, but it;s still a great pedal. Good design Jim.

BUT KRANKENSTEIN ROCKS!!!!! xD

So, what you are saying is that you really like the Krank? ;D I guess the layout is "verified" then?

I tell you man these Russians are not to be F#%ked with!!! They are the masters of this stuff... and these designs are 7 or 8 years old!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 18, 2013, 08:36:04 PM

Also R21's value of 1k on the schematic must be a typo. J201's maximum Idss is 1mA, so it cannot work there.


correct - R21 should be 10k
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 18, 2013, 08:37:30 PM
So... Have you made it final yet?  I'm dying to get started here, but want to wait til it's as final as possible before getting started.

Jeff, the last standard version without the add-on is very good in my opinion... build it! :icon_twisted:

This...
https://dl.dropboxusercontent.com/u/11178619/New%20Preamps/BF5%20-%20S.png

and this
https://dl.dropboxusercontent.com/u/11178619/New%20Preamps/BF5.pdf
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 19, 2013, 05:53:29 AM
Krankenstein done ... omg ... this one is a mother@#$%er ... gain is almost limitless :D. This one is the best so far. E3 and Krankenstein are going in the same box as my preamps and BF 4 fet is going to be tweaked a bit more, but it;s still a great pedal. Good design Jim.

BUT KRANKENSTEIN ROCKS!!!!! xD

So, what you are saying is that you really like the Krank? ;D I guess the layout is "verified" then?

I tell you man these Russians are not to be F#%ked with!!! They are the masters of this stuff... and these designs are 7 or 8 years old!

This one is odd ... at certain settings it sounds just like Devin Townsend while he was using 5150. And on the other hand it does Pantera and that kind of sound without breaking a sweat. E3 always sounds the same. And is better for certain extreme metal genre. Black, thrash, speed ... E3 has it. But krankenstein goes from 5150 to krank. It's better for death, sludge, stoner, doom. Even some EVH. It's interaction with guitars vol pot is better than with E3. Ps i think i've broke high and mid pots. It sounds like they are maxed all the time, and have no responce, no matter what i do. And it has this long beeeeeep. :D
It can be subdued with guitars vol pot. But it;s annoying.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 19, 2013, 06:28:59 AM
Ps i think i've broke high and mid pots. It sounds like they are maxed all the time, and have no responce, no matter what i do. And it has this long beeeeeep. :D
It can be subdued with guitars vol pot. But it;s annoying.

Damn-it! You think something is wrong on the layout perhaps??? pakrat is having problems with the krank also but not the same as yours... F$%K! :icon_evil:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 19, 2013, 06:31:54 AM
Well it worked last night. And in the mean time I've tried to put it in a box, but the holes didn;t match. So did it caveman style :D
And oh yeah, only mid pot is dead. :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 19, 2013, 06:52:41 AM
Well it worked last night. And in the mean time I've tried to put it in a box, but the holes didn;t match. So did it caveman style :D
And oh yeah, only mid pot is dead. :)

Can you verify before I pull all of my pubes out, roll them up and smoke them!? :icon_evil:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 19, 2013, 07:06:47 AM
Mid pot did the beeep. Any way I've placed 10k a pot for mids and it's more than enough. As far as I'm concerned. 2sk117 is my choice for q1. The beep issue is mids maxed + lots of gain. My advice here is to use 100k c pot for gain. Ive tried B and A and rev log would work so much better. And to add 1k-2k resistor between gain pot and that 4.5 volts ( since it's not touching the ground, but that middle line, which is 4.5 i'f i remember correctly ). And oh yeah, 100k pot for treble is enough as well. Maybe even 500k for bass. Sweep does most of the work here.

Perhaps this pedal would be better with bandaxall tonestack.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on April 19, 2013, 09:15:50 AM
Hey, I finished my Petruccifier (based on a Mk IIc+, including a simulation of the 5 band eq set on a big V shape) yesterday and it works, but intolerable fizz on the top... I have to do some tone shaping for sure.

But the thing that struck me is that it is so quiet! No hum, just the normal white noise you get at max gain. And it is not even boxed. And I used a messy vero board too. I used 2N5457 (5 stages of them).
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 19, 2013, 04:04:40 PM
My E3 died  :D it has octave up all the time and it's LoFi :D
I think the pots are responsible for LoFi. But octave up .... Any idea?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 19, 2013, 04:17:11 PM
I guess I would start with diodes and transistors, but what do I know. I built the Krank and it is definitely not right.... no sustain and crackly distortion. I just looked over everything and even double checked all values and it's all good. You have a working Krank built with no part substitutions?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 19, 2013, 04:30:06 PM
My E3 is still chuggin along... not sure whats up with that?? I did something once and got an octave up on-top of the regular signal but I can't remember what it was that I did??

pakrat... 6.5v on the 4.5v trace is not good.. I sent you PM.. double check that. Something is causing the voltage to be too high there.

To be honest, I am having more consistently good outcome making my own designs over these Russian ones... I have to remember they use Russian transistors and such.. not sure they make the transition to J201 very well... And with so many fakes floating around who the f@#k knows what yer gonna get?? Not sure about the 2SK117's.. I have never used any of those...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 19, 2013, 04:57:19 PM
For the Krank you guys may want to comb over this thread! He seems to have messed a lot with the Krank and had good results...
http://www.diystompboxes.com/smfforum/index.php?topic=89399.0
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 19, 2013, 05:28:16 PM
Hey, I finished my Petruccifier (based on a Mk IIc+, including a simulation of the 5 band eq set on a big V shape) yesterday and it works, but intolerable fizz on the top... I have to do some tone shaping for sure.

But the thing that struck me is that it is so quiet! No hum, just the normal white noise you get at max gain. And it is not even boxed. And I used a messy vero board too. I used 2N5457 (5 stages of them).

Damn-it man!! I want me a Petruccifier! :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 19, 2013, 05:46:56 PM
I guess I would start with diodes and transistors, but what do I know. I built the Krank and it is definitely not right.... no sustain and crackly distortion. I just looked over everything and even double checked all values and it's all good. You have a working Krank built with no part substitutions?
Well 2sk117 is  q1. And 10k pot for mids. But everything else ( bs170's for mosfets ). Did you use that 470k trim to find the sweet spot?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on April 19, 2013, 05:49:20 PM
Used krank as preamp ( into return of fender solidstate amp ) ... killer :D
Ps a friend of mine ( owver of that fender ) loved Krank and BF4.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 19, 2013, 06:50:17 PM
Replaced R8 to 2k and R14 to 3k and it's much better. Still getting 4.6v on the 4.5v rail so I'm going to R24 now. Sound is good, a little noisy and seems to be a bit unstable, in that the signal jumps in volume a little. Definitely on the right track though......
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 19, 2013, 07:13:02 PM
Swapped R24 for a 33k to lower to 4.5v but only got to 5v. Sounded like crap so I went back to 24k. Somehouw in all of this I got 2 broken joints for my pots during debugging.... fixed 'em and it's working! I am using J201 and 2n7000 as per the layout and it sounds great. The only changes I made were R8 to 2k and R14 to 3k and that got it working for me. Thanks for the input guys  :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 22, 2013, 05:32:09 PM
@Cap Is your layout verified Riccardo?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 22, 2013, 09:12:33 PM
@Cap Is your layout verified Riccardo?

+1

Looks like he built it but never heard anything after that??

Maybe I will etch it and try it... Somebody has to, might as well be me, right?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on April 23, 2013, 05:01:57 AM
right i have a spare breadboard at long last...... ::)

which schemo of these beasts to try first?...

one for good chunk, but good for flowing lead too, and chord definition...recommendations :icon_twisted: ?

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 23, 2013, 06:20:17 AM
right i have a spare breadboard at long last...... ::)

which schemo of these beasts to try first?...

one for good chunk, but good for flowing lead too, and chord definition...recommendations :icon_twisted: ?



I really like the E3 Engl and it needs some lovin... :icon_biggrin:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on April 23, 2013, 06:29:12 AM
hi jim:

funny i have that schemo on my desktop...

i'll try that then before anything else creeps onto my breadboard ::)...cheers man.

so j201/2n7000x3/ 2n5458x2

 8)

oh bollox, i haven't any 2n5458's....guess i'll have to sub em.. ::)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on April 23, 2013, 08:46:28 AM
Still voicing the Petruccifier. It sounds very good through an amp, but it is as a preamp direct to the PC with a cab sim (I tried an Engl 4x12, have to try some other ones) that it really gets there.
Actually as a preamp it sounds totally awesomely brutal and chunky :icon_evil:. It is prefect for hyper defined palm mutes, never had a sound that defined for that actually, it is like surgical precision. Marshall-type sound appears super bloated and messy compared to it.

I would like it to sound as good as a pedal so I have to add some switched voicing option to it. I probably have to have the option to switch off some of the insane scoop I put in the post eq since a clean deluxe reverb is pretty scooped to start with and the scoop is not even in the same spot which ends up causing a sound that is starting to sound hollow.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 23, 2013, 10:09:43 AM
Still voicing the Petruccifier. It sounds very good through an amp, but it is as a preamp direct to the PC with a cab sim (I tried an Engl 4x12, have to try some other ones) that it really gets there.
Actually as a preamp it sounds totally awesomely brutal and chunky :icon_evil:. It is prefect for hyper defined palm mutes, never had a sound that defined for that actually, it is like surgical precision. Marshall-type sound appears super bloated and messy compared to it.

I would like it to sound as good as a pedal so I have to add some switched voicing option to it. I probably have to have the option to switch off some of the insane scoop I put in the post eq since a clean deluxe reverb is pretty scooped to start with and the scoop is not even in the same spot which ends up causing a sound that is starting to sound hollow.

I want Petruccifier!!!  :icon_twisted: You make work NOW! :icon_evil:

 :icon_lol:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 23, 2013, 10:11:45 AM
hi jim:

funny i have that schemo on my desktop...

i'll try that then before anything else creeps onto my breadboard ::)...cheers man.

so j201/2n7000x3/ 2n5458x2

 8)

oh bollox, i haven't any 2n5458's....guess i'll have to sub em.. ::)

KP303A - 2SK30A-R, J201, 2N5457, 2SK30A-Y
KP303E - 2N5457, 2N5458, 2N5459, 2SK30A-Y

J201's work for both but not sure if they are the best choice?  I tried J201's, 2N5457's,2N5458's and 2SK30A-Y's in the end stages with very little difference... BIG differences in the first stage!

J201's, 2N5457's and 2SK30A-Y are my choice for the first stage and 2N5457's, 2N5458's and 2SK30A-Y for the last 2 amplifier/buffer stages.

People are using 2SK117's and reporting that they work well... I don't have any so I have no comment on them.

2N7000's and BS170's work about the same but the BS170's sound a little darker and have a little warmer sound...  same amount of gain.

I know there are a few other subs for J201 and 2N545X but I have not tried them / MPF102, NTE458 etc..
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on April 23, 2013, 10:18:42 AM
cheers for that jim,  i have it breadboard up to the 5th fet so far( no stack) ...and gain isn't that high really...

i'll check it over again... :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 23, 2013, 11:20:37 AM
cheers for that jim,  i have it breadboard up to the 5th fet so far( no stack) ...and gain isn't that high really...

i'll check it over again... :)

Are you using trimmers on the 2N7000's by any chance? The source and drain are pretty well dialed in on the schematic @ 43k source and 56k drain... Also R6, R13, R18 and gain pot critical to be attached to +4.5v comming from C18, R23 and R24 junction... without that no gain :icon_cry:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cap on April 23, 2013, 11:48:41 AM
@Cap Is your layout verified Riccardo?

+1

Looks like he built it but never heard anything after that??

Maybe I will etch it and try it... Somebody has to, might as well be me, right?

yes It works; I had some issues biasing, but than i realized that I have toasted a couple of fets when desoldering the first layout attempt :-\
The last time I played it, strange things happened: the first 5 minutes pure evil :icon_twisted: :icon_twisted:, then volume losses and eq problems..maybe other components are damaged..my bad

However the layout is correct, I'm pretty sure
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: miftah on April 23, 2013, 09:27:46 PM
thanks JOK3RX, i have j201 7pcs and i'll try it
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 23, 2013, 10:32:50 PM
thanks JOK3RX, i have j201 7pcs and i'll try it

I looked at your web page and went to your youtube link... nice stuff! How do you like the Infinity universal guitar preamp by chaosStrings?? I have the schematic and layout for that and I was going to build it. Your youtube vid sounds pretty good!!! Now I am really wanting to build... Do you like it?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: miftah on April 23, 2013, 11:39:11 PM
I looked at your web page and went to your youtube link... nice stuff! How do you like the Infinity universal guitar preamp by chaosStrings?? I have the schematic and layout for that and I was going to build it. Your youtube vid sounds pretty good!!! Now I am really wanting to build... Do you like it?
[/quote]

I like the infinity guitar preamp, but I do not like
because it uses duble voltage, and I had to buy
another transformer for it.
 
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on April 24, 2013, 12:08:16 AM
I looked at your web page and went to your youtube link... nice stuff! How do you like the Infinity universal guitar preamp by chaosStrings?? I have the schematic and layout for that and I was going to build it. Your youtube vid sounds pretty good!!! Now I am really wanting to build... Do you like it?

I like the infinity guitar preamp, but I do not like
because it uses duble voltage, and I had to buy
another transformer for it.
 
[/quote]

I see the +/-9V bipolar power supply in the schematic..could probably be redesigned to run on 9v or 18v? Haven't ever really looked at the schematic until now. Kinda surprised to see that it's just a BSIAB II with a lot of pre/post eq and filters... I wouldn't have guessed it was a BSIAB, doesn't really sound like one at all..?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: beedoola on April 27, 2013, 03:31:20 AM
J0K3RK - thanks for doing all the work with this!!

Is the parts list the same for the most recent version as for the first version on page 1 of this thread? I ask because the image/parts list on the 1st pages is easy to read for me than reading the component values on the layout picture.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: hangingmonkey on April 27, 2013, 03:52:43 AM
Ive got myself a pcb for the blacker forest, will that be ok with the updated no return layout?  Looks similar to me but with the 2 parallel 22k resistors changed to 11k and extra pads for d4.
Which layout should i use?
Any further amendments since?
Thanks
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Bliss on April 27, 2013, 10:09:31 AM
Well I'm planning to build this effect, great job!
But 43 pages of comments.. Could someone summarize what the changes to the original layout are? Or is there a final layout/scheme?

Thanks!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 27, 2013, 10:27:38 AM
I put together a BOM for the Black Forest No Return. I have checked it but another set of eyes would be nice...

Resistors 1/4W 1% Metal Film:

(1) 1M
(3) 68k
(3) 10K
(1) 5K
(1) 1.8K
(1) 100K
(1) 2.4K
(3) 470K
(2) 330K
(2) 1.5K
(1) 1K
(1) 820R
(1) 11K
(1) 220K
(1) 470R
(1) 100R
(1) 100K

Film Caps 35V-50V

(2) 1NF
(1) 100PF
(4) 2.2NF
(1) 470PF
(1) 22PF
(6) 22NF
(2) 470NF
(1) 270PF
(1) 220PF
(1) 1UF
(1) 100NF

Electrolytic caps 35V-50V

(3) 100UF
(1) 4.7UF
(1) 2.2UF

Trimmers:

(4) 50K Linear

Transistors:

(6) J201

Diodes:

(4) BAT85

Potentiometers PCB Mount:

(1) A100K
(1) B500K
(1) A20K
(1) B100K
(1) B50k-B100K
(1) A1M
(1) B1M (Optional Presence pot)

Switches:

(1) DPDT Toggle (Optional Wide Switch)
(1) DPDT Latching Footswitch (Optional Boost Switch)

Variac Board (Still under development and may have changed)

Resistors 1/4W 1% Metal Film

(1) 1M
(2) 10K
(1) 470R
(1) 33R
(1) 100K

Film Caps 35V-50V:

(1) 16NF
(2) 470NF

Electrolytic Caps 35V-50V:

(2) 100UF

Transistors:

(3) J201

Potentiometers:

(1) B250K
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 27, 2013, 10:30:45 AM
@Bliss I think the layout on page 41 is the most current version, and there are a few builds reported working off of that. Cap's version is smaller but I'm not sure it's 100% verified.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Bliss on April 27, 2013, 01:38:48 PM
@Bliss I think the layout on page 41 is the most current version, and there are a few builds reported working off of that. Cap's version is smaller but I'm not sure it's 100% verified.

Thank you pakrat!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on April 27, 2013, 03:45:45 PM
 ;)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Bliss on May 03, 2013, 10:46:19 AM
How close does the sound of this project get to the original Uberschall?
Is it a big difference?
Maybe someone who has a video or soundclip ?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on May 03, 2013, 11:31:59 AM
There are a few soundclips littered through the thread. I have built this preamp twice.... the first one was the noisy 5 gain stage version and aside from the noise, it sounded great. It definitely has the flavor of the Uberschall, but was too noisy. Then I built the 4 stage version and have not gotten it to work properly yet, but there are successful builds of that version so I'm still debugging  >:(
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on May 04, 2013, 01:19:54 PM
I just moved... still unpacking so, should be back in business soon, sorry...  :icon_confused:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: hari on May 14, 2013, 01:31:54 AM
still waiting for another build report . . .  :icon_biggrin:

i have my Blacker Forest PCB waiting for J201s, still confuse with the wiring, can I use only 1 3pdt switch, and ignore another swithces?


also waiting Jok3rx back to business  ;)

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Bliss on May 15, 2013, 03:26:52 PM
Is it possible to exchange the BAT85 diode for something else?
Since I'm ordering at one shop, does any of these compare?
    1N5817    
      1N5822    
      BAT41     
      BAT42     
      BAT46     
      SB360     
      SB560

Thanks,!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on May 15, 2013, 04:44:24 PM
I think any Schottky diode will work. Read page 39, there's some talk about it.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on May 15, 2013, 07:39:07 PM
Is it possible to exchange the BAT85 diode for something else?
Since I'm ordering at one shop, does any of these compare?
    1N5817    
      1N5822    
      BAT41     
      BAT42     
      BAT46     
      SB360     
      SB560

Thanks,!

What pakrat said...

I have used BAT41 and really like them.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on May 15, 2013, 09:26:07 PM
I tried the diodes and I got way less distortion! Did anyone else notice that drastic difference in perceived gain? No need to say I removed them instantly, it sounds just perfect without them anyway.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on May 15, 2013, 10:05:09 PM
I tried the diodes and I got way less distortion! Did anyone else notice that drastic difference in perceived gain? No need to say I removed them instantly, it sounds just perfect without them anyway.

Actually there is no need for these diodes in my opinion... They have little to no effect on my builds from what I can hear. I may hear a little difference when they are installed but that may just be my imagination... No gain loss that I can hear but I wouldn't be surprised if they did cause that in other builds given the wide variety of results that have been reported. Try BAV21 if you have any and tell me what you think? Just curious if you get what I am getting?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Bliss on May 16, 2013, 08:15:52 AM
Great thanks,
I think I'll order the BAT41 then, and just try if I like them or like it more without diodes. I'll check in with the results ;)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on May 16, 2013, 09:55:19 AM
I tried 1n58, then normal silicon 1N4148. It just killed the gain in both cases. It was not on the Black Forest but on another jfet circuit with similar structure.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: miftah on May 19, 2013, 10:09:24 PM
hi jim, I've build u'r  BF V.4 gain stage, and I like it very nice sound, this is video http://youtube.com/watch?client=mv-google&gl=ID&hl=en&v=4NPB78t5VZ4
Sorry for my bad playing..
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on May 19, 2013, 10:15:29 PM
Sounds great, nice vid miftah!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Bliss on June 26, 2013, 02:57:53 PM
Hmmmm, I'd like to bother you with some more questions..

I fixed some problems, it gives a pretty neat sound at the moment, but not right. The boost still doesnt work. Also the sound fades away in a strange way. I've uploaded two clips, in one you can hear me play and then turn on the boost. In the other I play just one note and wait till it fades, sounds strange right? Also notice the lack of low tones (I'm playing a jazz guitar over a bass amp)
https://www.dropbox.com/s/cbdvx4ruh86lh2y/boost.amr (https://www.dropbox.com/s/cbdvx4ruh86lh2y/boost.amr)
https://www.dropbox.com/s/7v1h7kwmzme1lxb/fade.amr (https://www.dropbox.com/s/7v1h7kwmzme1lxb/fade.amr)

To give you an idea of the progress so far: one of the things that helped me get from no sound at all to this was to set the trimpots at 5,5V and double check the soldering. I also connected all the optional "Wide Switch" holed trough wires, did seem to help though I'm not sure. is it okay to connect them? (1 connected to 2 and 3 to 4) . Also the Volume potmeter problem is fixed, as stupid as we are we ordered the wrong pot.... :icon_redface:

I hope you can help us with this information to getting the sound 100% right.

Thanks again for the help so far!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: MyKeul on June 26, 2013, 03:42:15 PM
Hi Guys,

I'm very intested in the Black Forest project but I can't find any J201, 2N5457 or 2N5458 where i'm used to order on the web.

I've posted my request 2 days ago and some of you answered me but yesterday, it was impossible to access the forum and this evening, i had the "surprise" to see that my account didn't exist any more (and my posts have disappear).

Could you please tell me again what FET to use instead of J201 (someone told me about JOK3RX's preference) ?

Another question : it seems that pots which are called "A" are LOG and "B" are LINEAR in the US while in Europe, "A" stands for LINEAR and "B" are LOG.
I'm lost in my choice; Should I use LOG or LINEAR for Volume, Gain, Bass, Mid, Treble ?

Thanx from France.

MyKeul.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Jopn on June 26, 2013, 04:07:52 PM
Hi Guys,

I'm very intested in the Black Forest project but I can't find any J201, 2N5457 or 2N5458 where i'm used to order on the web.

I've posted my request 2 days ago and some of you answered me but yesterday, it was impossible to access the forum and this evening, i had the "surprise" to see that my account didn't exist any more (and my posts have disappear).

Could you please tell me again what FET to use instead of J201 (someone told me about JOK3RX's preference) ?

Another question : it seems that pots which are called "A" are LOG and "B" are LINEAR in the US while in Europe, "A" stands for LINEAR and "B" are LOG.
I'm lost in my choice; Should I use LOG or LINEAR for Volume, Gain, Bass, Mid, Treble ?

Thanx from France.

MyKeul.

Hey MyKeul

The layout has the Log/Linear (ie. taper) letters beside the values found here: http://www.diystompboxes.com/smfforum/index.php?topic=98954.800
You're looking at linear for the gain and mid, and log for vol, bass, treble and voice.

J201s are fairly easy to come by, where do you usually order from?  Tayda and Furturlec both carry them, as well as most of the other "usual suspects".
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on June 26, 2013, 05:06:25 PM
Could you please tell me again what FET to use instead of J201 (someone told me about JOK3RX's preference) ?

I think JOK3RX likes 2SK30A-R but they are far more rare here than J201.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on June 26, 2013, 05:07:52 PM
@Bliss  Which version did you build? I had that same decay/gate problem with my 5 stage build. I never got it working after that......
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Bliss on June 26, 2013, 05:18:54 PM
@Bliss  Which version did you build? I had that same decay/gate problem with my 5 stage build. I never got it working after that......

I built the latest version (I guess) from page 41.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Bliss on June 26, 2013, 05:23:42 PM
@MyKeul,

I'm also ordering from Europe (The Netherlands) and had no problem with the Log/Lin.
I think Alpha prints the standard letters on the pots. Though I'm not 100% sure for france.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on June 26, 2013, 06:54:32 PM
In my opinion 5.5v is far too high... Try 4.7v or half of whatever voltage you are getting on the source power at that particular stage/jfet. The gate is made to be adjustable that is why there is a 1 meg pot there... you have to find the happy medium or "sweet spot" or you will get note decay and fizzling out sound. Honestly, I only use the gate maybe about 1/3 of the way up on full gain just to cut some of the inevitable high gain hum... If you get the jfet biased around the 4.7v range you can then fine tune them by ear, if you're good. :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: MyKeul on June 27, 2013, 01:26:45 AM
Thanx to all for your answers.

I'm used to order at mouser dot com and they don't have J201 (neither 2N5457 and 2N5458). I like this seler because they're very fast, not expensive and they sell lot of capacitors I really like in HI-FI amps.

I don't know tayda and furturlec; I'll have a look there.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Maik on June 27, 2013, 02:34:43 AM
Hey MyKeul, check out UK-Electronics. It´s in the neighbourhood, so it will be fast.
http://uk-electronic.de/onlineshop/product_info.php?products_id=247&osCsid=4ebdb042e640b54c178ff440b3d2d806
J201 for 0,48€
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on June 27, 2013, 02:34:53 AM

I'm used to order at mouser dot com and they don't have J201 (neither 2N5457 and 2N5458). I like this seler because they're very fast, not expensive and they sell lot of capacitors I really like in HI-FI amps.


Sure they do!
http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/MMBFJ201/?qs=%2fha2pyFadujHCFJwZJmrE7odvBpdRsrrdQ15sn4Bm54%3d

http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/MMBF5457/?qs=%2fha2pyFadugLayO0YJePXoBgS3AKmKkcvO%252b1%2fj%2f9%2fiU%3d

http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/MMBF5458/?qs=%2fha2pyFaduiQPyCWdWaokQt0OVpBllzsUlcwGhkguWo%3d

We are all gonna have to come to terms with SMD/SMT sooner or later... might as well get on with it! :icon_twisted:

I have been using the surface mount J201's and 2N7000's for quite a while now and call me nuts but I think they are better!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: ggedamed on June 27, 2013, 06:16:04 AM
In my opinion 5.5v is far too high... Try 4.7v or half of whatever voltage you are getting on the source power at that particular stage/jfet. The gate is made to be adjustable that is why there is a 1 meg pot there... you have to find the happy medium or "sweet spot" or you will get note decay and fizzling out sound. Honestly, I only use the gate maybe about 1/3 of the way up on full gain just to cut some of the inevitable high gain hum... If you get the jfet biased around the 4.7v range you can then fine tune them by ear, if you're good. icon_wink

I proposed 5.5V as a starting point. Considering a J201 that has Vp = -1V (most of mine have VP around -0.8..-0.9V), the available headroom is at 9 - 1 = 8V, and the middle point is 8/2 + 1 = 5V.
Oops, don't know what was I thinking when I wrote 5.5V. I guess I tried too hard to be smart  :icon_lol:.
Your value of 4.7V suits best a transistor with Vp = -0.4V, mine suits best a transistor with Vp = -2V, when they're supplied with 9V. They both work, even if the drain is not at the half-headroom point. In my circuits the trimmers get always replaced with resistors.

So it seems that the easiest way to bias a J201 is to set the drain voltage to half-voltage and then to adjust it a little bit upwards by ear. Of course, one may like it better when biased off-center.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: MyKeul on June 27, 2013, 08:02:49 AM
@ Maik : Thanx for UK-Electronics; not so far from me and I didn't knew them.

@ JOK3RX : I was looking for "standard" FET and hadn't thought about SMD as I don't really like them. I prefer the standard one because it's easier to swap components when they're on DIP brackets. But thanx for your suggestion  :)

I have to order every components (maybe today after work)...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on June 27, 2013, 08:30:54 AM
Bias at lower than center maximizes the available gain (bigger drain resistance on the trimmer) if you care about that (who does not care about crazy high gain anyway...).

On a similar design, I used some 2N5457 and it worked fine. I had to sort the lowest VGSoff I could find (-0.6 to 0.8volts) and bias around 4volts. It works very fine.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: ggedamed on June 27, 2013, 02:44:39 PM
Bias at lower than center maximizes the available gain (bigger drain resistance on the trimmer) if you care about that (who does not care about crazy high gain anyway...).

On a similar design, I used some 2N5457 and it worked fine. I had to sort the lowest VGSoff I could find (-0.6 to 0.8volts) and bias around 4volts. It works very fine.

Note that for the signal that passes through the source capacitor the gain is already maximized. The drain resistor / source resistor ratio has an effect only if the signal is outside the source capacitor bandwith or if there is no source capacitor.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Bliss on June 27, 2013, 05:44:09 PM
Thanks for all the information. We've played around with the voltages and it starts to sound quite allright. Though not like the Uberschall. Is it in any way possible to get it to sound like the Uberschall? Since that was our intention when we startet this project, but it seems to be a completely different sound....

Another point of trouble in our building is the boost, it still doesn't function at all. We've got no clue on the source of this problem.... Could it be an idea to add the variac board with two trimpots for volume and gain at the boost switch to add some more boost?

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on June 27, 2013, 07:21:09 PM
@ Maik : Thanx for UK-Electronics; not so far from me and I didn't knew them.

@ JOK3RX : I was looking for "standard" FET and hadn't thought about SMD as I don't really like them. I prefer the standard one because it's easier to swap components when they're on DIP brackets. But thanx for your suggestion  :)

I have to order every components (maybe today after work)...

whatever works for you...

(https://dl.dropboxusercontent.com/u/11178619/TO23%20-%20TO92.JPG)

Better example here
https://dl.dropboxusercontent.com/u/11178619/J201%20SMT%20converters.pdf

May seem like a lot of work but I can make a whole sheet of them, solder them, cut them and use in no time... I use the really thin pcb from ABCFAB on ebay.  good practice

Another thing I noticed is that I have yet to find a dud in the SMD j201's and they are all relatively on spec... call it luck, but I'm sold!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on June 27, 2013, 07:35:33 PM
Thanks for all the information. We've played around with the voltages and it starts to sound quite allright. Though not like the Uberschall. Is it in any way possible to get it to sound like the Uberschall? Since that was our intention when we startet this project, but it seems to be a completely different sound....

Another point of trouble in our building is the boost, it still doesn't function at all. We've got no clue on the source of this problem.... Could it be an idea to add the variac board with two trimpots for volume and gain at the boost switch to add some more boost?



Have you heard my sound clips? That is what mine sounds like... Says "based on Bogner Uberschall" not sounds just like a Bogner Uberschall. For obvious reasons that ain't gonna happen but mine sounds pretty damn good, I think?

in regards to the boost switch, you absolutely need to have at least one of those resistors going to ground or it will not work right or sound good at all! Why don't you forget the switch and just solder the switch end of the 68k directly to ground? Try it and report back.

By the way, if you don't even have the base layout working then building the variac board will only make matters worse!! Highly recommend holding off on that until you get the pedal working...

Keep in mind, this pedal has to have a combination of all things coming together and working correctly to produce a satisfying result! If one thing is outa whack it will not work correctly... Not a good beginner pedal to say the least! 
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on June 28, 2013, 12:05:24 AM
ggedamed,

Even when considering AC through the source bypass cap, there is the jfet intrinsic source resistor of the jfet and the ESR of the cap to take into account for the gain equation. It does not seem like much, but it count for a few dB of gain on an already relatively low gain device, then multiplied by 4 or five stages... You see the picture!

Actually, Rd always count in the gain equation of a jfet, even in pure common source configuration: the gain is proportional to Rd. It is also true for a bjt, I am not sure why you had the impression Rd (or Rc for that matter) did not influence the gain.

So in a nutshell, Rd is VERY important.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: MyKeul on June 28, 2013, 01:06:33 AM
Thanx JOK3RX, using your kind of "SMD PCB Adaptor" is a very good idea (why haven't I thought of this before ???).

Can I use the Black Forest which is on page 41 as it is in the post or are they any mods to do ? I must admit it's not really simple to me reading and understanding everything in English (maybe you could answer in French ? ;D).
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on June 28, 2013, 10:01:32 AM
I speak French fluently, so send me a private message if you have any question you want to ask.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: ggedamed on June 28, 2013, 07:32:29 PM
ggedamed,

Even when considering AC through the source bypass cap, there is the jfet intrinsic source resistor of the jfet and the ESR of the cap to take into account for the gain equation. It does not seem like much, but it count for a few dB of gain on an already relatively low gain device, then multiplied by 4 or five stages... You see the picture!

Actually, Rd always count in the gain equation of a jfet, even in pure common source configuration: the gain is proportional to Rd. It is also true for a bjt, I am not sure why you had the impression Rd (or Rc for that matter) did not influence the gain.

So in a nutshell, Rd is VERY important.

You're right. And thank you for making me to finally crunch some numbers.

I'll try here to make some thinking at my n00bish level.

I'm not sure about the JFET intrinsic source resistor and the ESR of the source cap - I'll say that first is in the tens of ohms regions and the second in the ohms region. Let’s presume that the sum of the two resistances is 50 Ohm, for the sake of this example.

Let’s take a J201 JFET with Vp = -0.8V and Idss = 0.75mA.

I’ll settle for Id = 0.4mA and Rs = 1 kOhm, because it’s almost half the usual 1k8 value for the source resistor - this  will maximize the effects of the drain resistor modifications in the absence of the source capacitor.

The drain voltage for maximum headroom will then be (9 - 0.8 )/2 + 0.8 = 4.9V, which gives Rd = (9V - 4.9V) / 0.4mA = 10.25 kOhm. The headroom on the both sides of the amplified signal is 4.1V (theoretically).

Maximum gain is Av = - (gm * Rd) / (1 + gm * Rs), where gm is the transconductance of the JFET, maximum 0.5mS for J201 (and a typical 15mS for 2SK117!).

So the gain of the stage will go along the bandwith from -3.42 times (~10.67dB) to -5 times (13.98dB).

Now, let's increase Rd until the headroom on the negative side is only 0.5V. This means that the drain voltage will be 0.8 + 0.5 = 1.3V, which leads to Rd = (9V - 1.3V) / 0.4mA = 19.25 kOhm.

The gain will now be between 6.42 times (16.15dB) to 9.39 times (19.45dB). Meaning an average increase of 5.5dB. Almost double.

Which is good, BUT the signal will be extremely clipped. The resulting signal will be distorted from almost the start. Which could be quite fine for many. What I like when the bias aims for maximum headroom is that the sound will pass a much larger range of transformation from almost clean to extremely distorted, depending on how hard one picks the strings.
So, this additional gain wil come at the expense of the "responsiveness" of the effect.

One more efficient way to increase gain seems to use JFETs with larger transconductance like 2SK117. When calculated for a 2SK117-Y with Vp = -0.55V with the same 1 kOhm source resistor, the gains for the maximum output headroom were from 9.9 times (19.91dB) to 90.54 times (39.14dB!!!). Not counting the much lower noise of 2SK117.
I'm not sure my calculations are entirely correct, yet I know that I only needed 3 stages with 2SK117 instead of 4 or 5 stages with J201 for this example of bad playing:



Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on June 28, 2013, 07:49:05 PM
You have a pretty versatile distortion there. Great vid ggedamed!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on June 28, 2013, 11:39:26 PM
ggedamed,

I agree, the trick to maximize the gain is to bias under V+/2, maximizing Rd without killing the sound quality. Probably about 3.5 to 4 volts is still fine.

Switching to higher gain jfet is even better, as long as the Vgs off / Vp is still low enough to allow Vd to stay high...

Subtle!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 07, 2013, 12:29:39 PM
Hey guys i'm new here and i've readed the entire post... that was inspiring. I would like to sahre with you this pedal/preamp i've designed recently y hope you enjoy it

 (http://s21.postimg.org/6o0f2dehj/Aggression_Mu.png) (http://postimage.org/)
subir gif (http://postimage.org/index.php?lang=spanish)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 07, 2013, 12:46:10 PM
Here a sound test https://soundcloud.com/palo-bonilla/aggression-mu-test (https://soundcloud.com/palo-bonilla/aggression-mu-test)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on August 07, 2013, 06:15:14 PM
Great sounding clip palobonilla, thanks for sharing. Welcome to the forum!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: kingswayguitar on August 07, 2013, 08:41:55 PM
Here a sound test https://soundcloud.com/palo-bonilla/aggression-mu-test (https://soundcloud.com/palo-bonilla/aggression-mu-test)

holy crap
3 mu-amps in series
over the very top 4 sure
love it
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 07, 2013, 08:45:15 PM
Hey guys i'm new here and i've readed the entire post... that was inspiring. I would like to sahre with you this pedal/preamp i've designed recently y hope you enjoy it

 (http://s21.postimg.org/6o0f2dehj/Aggression_Mu.png) (http://postimage.org/)
subir gif (http://postimage.org/index.php?lang=spanish)

oh baby! Please share layout!!!  :icon_twisted:

Love it!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: kingswayguitar on August 07, 2013, 08:47:28 PM
@ ggedamed

scoopy...i love it
there's a guy at work, last name Schoolcraft
we call him scoopy
long story
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 07, 2013, 08:51:40 PM
i dont have a good layut by now :S but i will work in that for sure
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: posmaster on August 07, 2013, 09:07:05 PM
Hey guys i'm new here and i've readed the entire post... that was inspiring. I would like to sahre with you this pedal/preamp i've designed recently y hope you enjoy it

 (http://s21.postimg.org/6o0f2dehj/Aggression_Mu.png) (http://postimage.org/)
subir gif (http://postimage.org/index.php?lang=spanish)

Any particular reason for the 1458, or would any decent dual op-amp work (TL072, etc)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 07, 2013, 09:15:22 PM
yup any decent opamp will do the work
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 07, 2013, 09:26:59 PM
So, your demo was on bread board then? What was your signal chain, hope you don't mind me asking...?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 07, 2013, 09:45:21 PM
hehehehe yes the thing were mounted on a bread board. The signal chain was guitar -> pedal -> audio interface -> revalver MKIII ( i used a peavey 6505 with flat settings and the default 2x12 cabinet). I already have the ting in a pcb but i designed it with PCB wizzard and is not so good.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 07, 2013, 09:51:37 PM
I already have the ting in a pcb but i designed it with PCB wizzard and is not so good.

To me it doesn't matter... If it sounds good, then it is good! And, it sounds damn good!  :icon_wink:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 07, 2013, 10:27:09 PM
Quote
To me it doesn't matter... If it sounds good, then it is good! And, it sounds damn good!  icon_wink
well, here are the PCB i hope you get through taht mess  :icon_biggrin:. By the way you can see the values of the components if you doubleclick them. http://www.filehostfree.com/?d=520301831 (http://www.filehostfree.com/?d=520301831)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 07, 2013, 11:02:48 PM
Quote
To me it doesn't matter... If it sounds good, then it is good! And, it sounds damn good!  icon_wink
well, here are the PCB i hope you get through taht mess  :icon_biggrin:. By the way you can see the values of the components if you doubleclick them. http://www.filehostfree.com/?d=520301831 (http://www.filehostfree.com/?d=520301831)

mess ha ha... That ain't a bad layout at all!  :icon_wink: Hell, all my layouts look like Sha Ca Ca...  I'ma build me one! You ROCK!!!  :icon_twisted: Thank You Thank You!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 07, 2013, 11:11:27 PM
Quote
mess ha ha... That ain't a bad layout at all!  :icon_wink: Hell, all my layouts look like Sha Ca Ca...  I'ma build me one! You ROCK!!!    :icon_twisted: Thank You Thank You!!
that´s nothing buddy enjoy it!!!!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on August 08, 2013, 12:15:18 PM
bummer, my pc wont play soundcloud files for some reason... ::)

looks like a cool distortion man. :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: ggedamed on August 08, 2013, 02:06:11 PM
Whoa, that's massive! I like the Twin-T switch, it's a cool ideea. You should make its own thread, it deserves it.

Man, I remember the days when I had time and no ideas, except changing the clipping diodes :icon_lol:. My to-do list is getting bigger and bigger. I wonder how many stages would be needed with 2SK117 or 2SK170.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 08, 2013, 03:40:40 PM
Quote
I wonder how many stages would be needed with 2SK117 or 2SK170

That's a good question, maybe two, who knows  ;D

Quote
I like the Twin-T switch, it's a cool ideea

Yeah, wellfor a good sounding pedal you need to kill some of the high-mid range that comes from the preamp sound but you first need to find the right frequency to notch, is not the same in evey case, i'm working on a twin - t for a dr. boogie i built long time ago   :icon_biggrin:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 08, 2013, 07:06:24 PM
Whoa, that's massive! I like the Twin-T switch, it's a cool ideea. You should make its own thread, it deserves it.

Man, I remember the days when I had time and no ideas, except changing the clipping diodes :icon_lol:. My to-do list is getting bigger and bigger. I wonder how many stages would be needed with 2SK117 or 2SK170.

Totally agree, sounds MASSIVE as you say and really should make a thread just for this beast!!! And I gotta say the playing is excellent as well!!

I know what you mean about your "to-do" list... mine is a thousand miles long and I only got my 1 mile walkin shoes on :icon_rolleyes:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 11, 2013, 02:58:13 PM
hehehehe yes the thing were mounted on a bread board. The signal chain was guitar -> pedal -> audio interface -> revalver MKIII ( i used a peavey 6505 with flat settings and the default 2x12 cabinet). I already have the ting in a pcb but i designed it with PCB wizzard and is not so good.

palobonilla,

Please answer if you are still around...!


In looking at your signal chain it concerns me that you are running into the Peavey 6505 software amp modeling head! I am wondering if a lot of the monster tone and magic is coming from the 6505 especially since it is the last in line before the cab!? Can you just bypass the 6505 and go direct into the 2X12 combo? Or, use a power amp simulator instead of the 6505 if you really need to have some sort of buffer/amp before the cab. By the way, what was the gain setting on the 6505?? Maybe you can use some impulses made with power amp and cabs? Anything that will truly show the tone, gain and dynamics of this preamp...

Thanks,
Jim
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 12, 2013, 07:27:37 PM
Well, I will know soon... almost done with my build.  :icon_lol:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on August 14, 2013, 01:32:54 PM
^ you talking to yourself again?... ;D

i often do too ::)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 14, 2013, 07:45:00 PM
^ you talking to yourself again?... ;D

i often do too ::)

yeah... I should join the DIYSB forum a couple more times with different names for my other 2 personalities so I can get some damn support around here :icon_twisted:

J0K3RX  :icon_twisted: J0K3RY  :icon_evil: and J0K3RZ  :icon_cool:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 15, 2013, 03:48:53 AM
Got it built, this Aggression Mu and I have to say I am VERY disappointed! Looks like a beast and sounded like one in the demo? :icon_cry: But, it sounds nothing like the clip we heard??? No presence, average amount of gain about the same as a stock BSIAB... I think the sound demo was mostly software amp simulation...? I even tried it in ReValver III with 6505 amp and even the 6505 power amp with default cabs and not EVEN remotely like the sound we heard in the demo! WTF?? I will go over it again with the schematic but I was pretty damn thorough the first time around! Any ideas before I re-claim all these friggin J201's on this thing? And holy crow, there's a butt load of 1u caps as well....  :o  Muddy, muffled, bass heavy and not much gain... even a tube screamer in front of it doesn't get it chunkin? I would have waited for somebody else to build it first but I would have turned 80 years old by the time that happened... so I did it :icon_rolleyes: Please tell me I am not a fool ???
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on August 15, 2013, 04:06:07 AM
@jim, jokerx,jokery,jokerz... ;D

yeah demo's should be 'pedal only' especially with distortions imho..no trimmings,sims ,EQ's  etc, it gives a false representation of what it really is...kinda pointless really.

you just want to hear the 'potential' of it... :icon_evil:

don't you do breadboarding?.

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on August 15, 2013, 08:30:36 AM
Weird... 3 mu-amps in a row should have a truckload of gain! Each mu-amp must have like 10 times more gain than a simple jfet stage!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 19, 2013, 03:18:27 PM
Quote
Got it built, this Aggression Mu and I have to say I am VERY disappointed! Looks like a beast and sounded like one in the demo? icon_cry But, it sounds nothing like the clip we heard??? No presence, average amount of gain about the same as a stock BSIAB... I think the sound demo was mostly software amp simulation...? I even tried it in ReValver III with 6505 amp and even the 6505 power amp with default cabs and not EVEN remotely like the sound we heard in the demo! WTF?? I will go over it again with the schematic but I was pretty damn thorough the first time around! Any ideas before I re-claim all these friggin J201's on this thing? And holy crow, there's a butt load of 1u caps as well....  Shocked  Muddy, muffled, bass heavy and not much gain... even a tube screamer in front of it doesn't get it chunkin? I would have waited for somebody else to build it first but I would have turned 80 years old by the time that happened... so I did it icon_rolleyes Please tell me I am not a fool Huh


 :-\ uploading a only pedal in preamp mode clip, wait
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 19, 2013, 03:22:55 PM
here are the track https://soundcloud.com/palo-bonilla/ptest (https://soundcloud.com/palo-bonilla/ptest)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 19, 2013, 04:19:02 PM
recently recorded, only the pedal and the cab https://soundcloud.com/palo-bonilla/ptest2 (https://soundcloud.com/palo-bonilla/ptest2)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 19, 2013, 06:40:29 PM
recently recorded, only the pedal and the cab https://soundcloud.com/palo-bonilla/ptest2 (https://soundcloud.com/palo-bonilla/ptest2)

Man yours sounds awesome!!  ??? I wonder wtf I did wrong here?? I even used your board layout. Are you sure all the part values are correct? I am gonna mess with mine tonight and see if I can figure it out... Any voltages might be helpful? Damn-it! Yours sounds great man!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 19, 2013, 06:44:07 PM
Quote
Man yours sounds awesome!!  Huh I wonder wtf I did wrong here?? I even used your board layout. Are you sure all the part values are correct? I am gonna mess with mine tonight and see if I can figure it out... Any voltages might be helpful? Damn-it! Yours sounds great man!!

Hey James, you used it like a pedal? or like a preamp? remember if you gonna use it lik a preamp you need to bypass the twin T, i will post the voltages tomorrow i'm a little busy right now, but what you need just tell me
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 19, 2013, 06:45:39 PM
i will verify the layout too  ;)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 19, 2013, 07:05:55 PM
i found a mistake on the value of one resistor, it´s marked on the layout as 100 ohm (green circle on the image) but actually it´s 470k i hope this fix the problem (http://s23.postimg.org/7lb5s4ujf/Sin_t_tulo.png)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 19, 2013, 07:22:26 PM
ok, i have checked the entire layout  values an there were a LOT of mistakes

(http://s24.postimg.org/3ory7cucl/Sin_t_tulo.png)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 19, 2013, 07:56:45 PM
I am using it like a preamp into a cab simulator straight into Reaper. I see the corrections you have found, that's great! I will try those and go over the schematic against the layout just in case there are anymore... I was sure I got it 100% with the layout but the changes should help, I hope!? Thanks man! It just sounds insane in your clips so I gotta get this thing!! And the tone stack sounds very functional in your sound clips as well which is rare with that type of tone stack!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 19, 2013, 08:00:24 PM
Quote
I am using it like a preamp into a cab simulator straight into Reaper. I see the corrections you have found, that's great! I will try those and go over the schematic against the layout just in case there are anymore... I was sure I got it 100% with the layout but the changes should help, I hope!? Thanks man! It just sounds insane in your clips so I gotta get this thing!! And the tone stack sounds very functional in your sound clips as well which is rare with that type of tone stack!

You're welcome James, i'm shure that the corrections will fix your pedal but in any case just tellme i will be glad to help you, by the way yes the tone stack works fine it's almost the same used in a old schematic of the dr. boogie

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: caspercody on August 20, 2013, 10:06:36 AM
Anyway to get a recording using it into a amp?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 20, 2013, 01:29:36 PM
Quote
Anyway to get a recording using it into a amp?

I don´t have an amp but i´m thinking about borrow one and make a videoclip, just need some time
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 20, 2013, 11:10:17 PM
Is it just my eyes and few remaining brain cells :o or is source and drain mixed up on this??? I mean according to the standard pinout of a J201...? Please another set of eyes!! I am tired so I could be having hallucinations... This layout is backwards and upside down to what I am used to working with so it's driving me nutso :icon_eek:

Oh, and the two caps C2 and C3 are supposed to be 15n not 10n... my bad!

(https://dl.dropboxusercontent.com/u/11178619/Other/pinout1.png)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Roger Martin on August 20, 2013, 11:19:21 PM
I love it when you guys make a complete project topic like this.
PCB + schematic + mp3 demo.
Many thank yous to generous good guys like JOK3RX Jim, Galego, Slade, Merlin B, DeadAstronauts Rob H and many more i haven't mentioned.  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 20, 2013, 11:26:12 PM
I love it when you guys make a complete project topic like this.
PCB + schematic + mp3 demo.
Many thank yous to generous good guys like JOK3RX Jim, Galego, Slade, Merlin B, DeadAstronauts Rob H and many more i haven't mentioned.  ;D

Roger, you can thank palobonilla for this one... And if it works then even better!!

Now, what do you think of the J201 orientation in the layout??
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 21, 2013, 12:07:01 AM
c'mon.... too many smart people here not to verify...  :icon_cry: I am dyslexic so help a handicapper out here!!   :-*
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: palobonilla on August 21, 2013, 12:46:08 AM
Quote
c'mon.... too many smart people here not to verify...  icon_cry I am dyslexic so help a handicapper out here!!   Kiss

Yeah those are reversed, but it doesent matters, i have just mount a probe circuit in the bread board testing the jfets drain a source reversed and not reversed there is no difference
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on August 21, 2013, 04:48:59 AM
looks weird to me too..
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: caspercody on August 21, 2013, 09:23:33 AM
Just looking at the first JFET, and the Source and Drain are wrong. They need to be swapped with each other.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 21, 2013, 07:40:01 PM
Tried both ways with the jfets and with the new part values and still doesn't work...  :icon_rolleyes:

It passes signal but clips and squeals so badly that it completely kills the signal until the note decays. Pure white noise and one note sends it into a full on clip and kills the signal..? Something ain't right here and I know I have all of the values correct according to the layout, no solder bridges, shorts etc... I also tested all resistors and jfets used and all are correct and working good.  rcustoms created a layout for it going from left/input to right/output using only the schematic as reference. I may try that if I find some time but at this point I have to lay it down.. I have too much going on and I have a couple other great sounding pedals like the tight metal that I am finishing up. Unless somebody comes up with a "verified" ground breaking fix, it's off to the bone pile for this where it will be slowly stripped of all components until there is nothing left but a rotting carcass of a circuit board... ashes to ashes, dust to dust :icon_evil:  
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on August 22, 2013, 03:05:30 AM
@jim:  do you just build without breadboading first?....just curious.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: caspercody on August 22, 2013, 09:53:12 AM
Not sure if it matters, but after looking over the PCB layout the first stage JFET drain is not connected directly to Vdd. It is connected to R6 (the side not connected to Vdd).

Not sure what type of JFET was used on the PCB, but it looks like the drain and source are reversed. A J201 pin out is:

G
S
D

The pin out on the PCB appears to be:

G
D
S

Thanks
Rob

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 22, 2013, 07:05:22 PM
@jim:  do you just build without breadboading first?....just curious.

depends... if I had more time and space I would breadboard more but for me it's quicker to just etch and populate.. If it's got a large number of components I usually don't breadboard. I get distracted and pulled away a lot and when I come back to a breadboard with a lot going on I have to remember where I left off which usually takes me a good bit of time. I have kids running all around and go to work then come home and stuff has been moved etc...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 15, 2013, 04:14:33 PM
Anybody see anything wrong with this schematic???  :icon_neutral:

(http://s21.postimg.org/6o0f2dehj/Aggression_Mu.png)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: GSmith on November 05, 2013, 03:09:06 PM
Hi guys! No capacitor in parallel with 9v ? ???
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Ice-9 on November 05, 2013, 03:19:48 PM
@jim:  do you just build without breadboading first?....just curious.

depends... if I had more time and space I would breadboard more but for me it's quicker to just etch and populate.. If it's got a large number of components I usually don't breadboard. I get distracted and pulled away a lot and when I come back to a breadboard with a lot going on I have to remember where I left off which usually takes me a good bit of time. I have kids running all around and go to work then come home and stuff has been moved etc...

Sometimes I cad and etch a pcb instead of breadboarding, it can be quicker and more practical at times.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on November 05, 2013, 06:02:18 PM
Hi guys! No condencator in parallel with 9v ? ???

There is a RC filter for each stage (R6/C7, R13/C13, R18/C19), so no need for a capacitor placed at Vdd for these to have clean power.

Would need one to filter for the rest of the circuit though, you are right.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: GSmith on November 06, 2013, 11:50:46 AM
Hi Jymaze...Have you try? Does it help? Not at home this week but wanna look further with this circuit, think I'll put it on a protoboard this WE...
What´s wrong Jok3erx with your build? How Is the signal before the operational amps stages?
Not very usefull but... why put a 220p on Q2 & Q6 (between D & S) and not on Q4?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Pojo on November 06, 2013, 02:50:48 PM
Doesn't the signal going into the opamps need to connect to Vaa through a large resistor to keep the signal half-way between the power rails? Looks like the signal coming out of the last mu-stage goes right into the + input of the opamp.....I'm probably missing something though.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on November 06, 2013, 08:29:43 PM
I haven't tried it, too many other projects. The opamps are correctly biased as the muamp output should be at about 4.5V if the jfets are not too mismatched. This circuit should be perfectly functional. Actually the only caveat I would see is too much gain, hence noise and unstability!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on November 06, 2013, 10:01:21 PM
I tried it twice but no dice..  :-\ I tried the layout from the original poster palobonilla and another layout that Rcustoms made. I went over both layouts extensively with no luck so I shelved it and moved on to other stuff I was working on at the time. The sound demo lured me in and I am still drooling over it! I have found a few other schematics in various Russian forums that are similar to this one and I don't doubt that it will work. I may try to bread board it one stage at a time or I may try to make my own layout. At the moment I am working on some other stuff so it's still eating at me... I don't like to be defeated :icon_evil:

FYI - You better stock up on 1u caps if you're gonna build it... This is loaded with them!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: jymaze on November 07, 2013, 09:04:56 AM
Maybe you should do some voltage readings around the semi-conductors and post them? This thing should work and have insane gain!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: frankenfurter on November 19, 2013, 06:19:06 PM
Hi Jok3rx,
really awsome work!!! Which BF schematic would be the latest?
Cant wait to build this thing!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: DEVASTATOR on November 29, 2013, 11:58:42 AM
can i use 2sk170 transistors , for this preamp ?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: j2sip on February 01, 2014, 05:11:19 AM

A newbie very late to the party..

Does the BOOGAZY layout contain/includes a clean channel? I'm very keen on a clean-crunch-more crunch pedal based on this very awesome design..

Thanks to JOK3RX!

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 01, 2014, 10:33:55 AM

A newbie very late to the party..

Does the BOOGAZY layout contain/includes a clean channel? I'm very keen on a clean-crunch-more crunch pedal based on this very awesome design..

Thanks to JOK3RX!



Did I make a Boogazzy layout, I don't remember? :icon_rolleyes: Got a link?  :icon_lol:

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 01, 2014, 11:18:56 AM
BTW - A very talented guy in Indonesia by the name of Arzone made a really nice 1590b layout for the BF5...  I may have to build it myself sometime! :icon_wink:

Schematic
https://dl.dropboxusercontent.com/u/11178619/BF5/BF5_sch.jpg

youtube
https://www.youtube.com/watch?v=3HjxeRFr2hI

(https://dl.dropboxusercontent.com/u/11178619/BF5/Loaded.jpg)

(https://dl.dropboxusercontent.com/u/11178619/BF5/1590b.JPG)



Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: pakrat on February 01, 2014, 08:51:44 PM
That's a nice compact layout. It's good to see this project is still alive, guess I need to give it another try  :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: selfdestroyer on February 01, 2014, 11:10:08 PM
J0K3RX,
DId Arzone make this layout available? I made your 1590B Triple Wreck and I would love to build this one also.

Cody
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 01, 2014, 11:18:06 PM
J0K3RX,
DId Arzone make this layout available? I made your 1590B Triple Wreck and I would love to build this one also.

Cody

Yup! I gots it... Ya want it? :icon_mrgreen:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: selfdestroyer on February 01, 2014, 11:23:15 PM
J0K3RX,
DId Arzone make this layout available? I made your 1590B Triple Wreck and I would love to build this one also.

Cody

Yup! I gots it... Ya want it? :icon_mrgreen:

Perty Please. I am itching to start a build tonight.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 02, 2014, 12:29:58 AM
J0K3RX,
DId Arzone make this layout available? I made your 1590B Triple Wreck and I would love to build this one also.

Cody

Yup! I gots it... Ya want it? :icon_mrgreen:

Perty Please. I am itching to start a build tonight.

Check yer email...  :icon_wink: Anybody else wants it PM me.. not gonna post it here

I doctored it up a bit, not much... Just tried to make more clearance on some of the traces. Watch out for shorts!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: j2sip on February 02, 2014, 12:48:57 AM

A newbie very late to the party..

Does the BOOGAZY layout contain/includes a clean channel? I'm very keen on a clean-crunch-more crunch pedal based on this very awesome design..

Thanks to JOK3RX!


Did I make a Boogazzy layout, I don't remember? :icon_rolleyes: Got a link?  :icon_lol:

http://www.diystompboxes.com/smfforum/index.php?topic=98954.380 (http://www.diystompboxes.com/smfforum/index.php?topic=98954.380)

There you go, kind Sir. reply #386.. I'm kinda stoked by your enthusiasm about these pedals. And uh, i also want the new layout of the BF5, if I may.
Thanks!


Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: selfdestroyer on February 02, 2014, 01:08:08 AM
J0K3RX,
DId Arzone make this layout available? I made your 1590B Triple Wreck and I would love to build this one also.

Cody

Yup! I gots it... Ya want it? :icon_mrgreen:

Perty Please. I am itching to start a build tonight.

Check yer email...  :icon_wink: Anybody else wants it PM me.. not gonna post it here

I doctored it up a bit, not much... Just tried to make more clearance on some of the traces. Watch out for shorts!

Thanks so much, To the cave to etch!

Cody
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on February 03, 2014, 08:44:38 PM
J0K3RX,
DId Arzone make this layout available? I made your 1590B Triple Wreck and I would love to build this one also.

Cody

Yup! I gots it... Ya want it? :icon_mrgreen:

Perty Please. I am itching to start a build tonight.

Hey man, if you build it hows about a sound demo? Also, I would like to hear the triple wreck if it wouldn't be too much of a problem? You don't even have to post it here if you don't want to, you can just send me a couple chuggin power chords or whatever... The same goes for anybody who builds the 1590b layout...please :icon_neutral:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Maik on April 24, 2014, 02:41:02 PM
Thanks JOK3RX  :icon_biggrin:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on May 12, 2014, 03:08:49 AM
Trying the Black Forest with MOSFET... I think it will be the most brutal of all!....? :icon_twisted:  See any problems with it?  ???

https://dl.dropboxusercontent.com/u/11178619/BF_MOSFET/Black%20Forest%20Mosfet%20Basic%202.pdf

(https://dl.dropboxusercontent.com/u/11178619/BF_MOSFET/Black%20Forest%20Mosfet%20Basic%20Rev.2.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: duck_arse on May 12, 2014, 11:39:17 AM
erm, those mosfets, they'd be wanting some positive bias voltage?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on May 12, 2014, 07:14:43 PM
erm, those mosfets, they'd be wanting some positive bias voltage?

Yes, and they do...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: duck_arse on May 13, 2014, 10:53:56 AM
did you just add a line right the way across the bottom, or was I just not paying attention again?

yr last mosfet still no dc bias.

that first jfet wiring is frejking me out, now. what's the 50k pot control?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: stormbringer79 on May 25, 2014, 05:17:36 PM
Its a trimpot, to adjust the bias.

Jfets are not very reliable in manufacturing, hence the biasing by trimpot.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on May 25, 2014, 06:15:03 PM
Its a trimpot, to adjust the bias.

Jfets are not very reliable in manufacturing, hence the biasing by trimpot.

yup, what stormbringer79 said... I should have marked it "50k trim" and also it probably looks strange since I connected it using the "non conventional method" with pin 3 to ground.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on May 25, 2014, 10:23:31 PM
Still not satisfied with the straight Marshall type tone stack. It's alright but lacks independent frequency control and range. The sweep pot helps a lot but still not quite all there yet, if ya know what I mean...

I have been looking at this, seems like it could be set up to be very functional if you get the right frequencies... Anybody try/use this with any success?

(https://dl.dropboxusercontent.com/u/11178619/Tone_controls/greq.gif)

(https://dl.dropboxusercontent.com/u/11178619/Tone_controls/Graphic%20EX%20-%20TS.jpg)

Another more commonly seen approach...

(https://dl.dropboxusercontent.com/u/11178619/Tone_controls/newdrbts.png)

Here are some various older Peavey stacks in a zip. I find these quite interesting! I believe James Brown from Amptweaker designed or co-designed most of these throughout his 18 years at Peavey ... Of course, he's better known for the 5150 amp design. He seems to know how to get "The Tone" being lead engineer with Eddie Van Halen on his amps for 13 years and worked with Joe Satriani to develop the original JSX amp... Pretty damn impressive resume' if you ask me! The man certainly knows his craft! I figure probably a good source to grab some ideas from...
https://dl.dropboxusercontent.com/u/11178619/Peavy_tone_controls/peavey%20tone%20controls.zip
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: ggedamed on May 27, 2014, 07:01:58 AM
Most of the graphic EQ pedals use the gyrator topology depicted in your first schematic (which is from R.G.'s site), although some use op amps instead of BJTs in the gyrators.
Even with standard EQ pedal frequencies, a graphic EQ will be miles ahead of the Marshall tone stack. If you're not sure if it would work for you, it's easy enough to fit an EQ pedal in the appropriate place.
BUT, since a long time ago, I'm carrying this in the back of my mind (from http://geofex.com/ (http://geofex.com/) - look for Simple, Easy Parametric and Graphic EQs at the bottom of the page):
Quote from: R.G. Keen
Some recent commentary from Ed Rembold, Mark Hammer, and others has suggested that the ideal EQ for guitar use may be a hybrid of the graphic and parametric EQ's. Some players have contended that they need the greatest flexibility and adjustability between 700Hz and 1500Hz, not simply a couple of fixed bands, while they would prefer to have the bands of a graphic EQ bunched up a bit below these frequencies. Instead of a 60/120/240/500 Hz set of bands, perhaps only two or three bands at 80-100/200/400 Hz would be enough; a similar setup above the 700-1500 Hz range would allow adjusting treble. There is still some work going on in these areas.

As an aside, I'm experimenting with a LPF for controlling the treble, since I've never wanted more treble than the circuit is capable of providing. I have on my long overdue to-do list an EQ containing a variable HPF (bass), a variable LPF (treble) and 1-3 band parametric EQ for the mids. I even have the HPF+LPF part on a breadboard that I've not touched since the beginning of 2013 :'(.

The last one is a variant of the James tone stack (the "passive Baxandall"). It has big signal loss, its controls interactivity is still significant and the bandwith per control is fairly wide, so it seems not a good match for extreme distortions.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on May 27, 2014, 04:03:56 PM
ggedamed - thanks for the input! I too was thinking of a HPF+LPF+parametric EQ type thing.. The best way for me to find out what will be a good choice will be to test and then test and then do some more tests... Been on my "things to do" list along with 1000 other things for quite some time.  :icon_rolleyes:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: GORENOISE on June 29, 2014, 08:55:44 PM
hi all, i'm new in the forum and i been reading this post,.. Tomorrow i'm going to the shop to buy the parts but, what version of bf recommend?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: duck_arse on June 30, 2014, 10:45:21 AM
well, now, which fets? for the mosfets, you can use 2N7000 or BS170, maybe VN10K. try all three! whichever you buy, get the datasheet and check yr pinouts! (and the last mosfet stage of the last posted version still needs some dc bias, to my eyes.)

as for the jfets, just about anything you can lay your hands on. J201 and 2N5457 are the most popular. they will both sound different. you can also try 2N5458, 2N5484 or 5, BF245A or B, 2N5952 or 3, 2SK30 and loads of other 2SK-types, many others.

some of those are backwards to the others, so you gotta get the datasheet to know for sure. good luck and welcome to the forum.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: verr76 on July 11, 2014, 01:31:12 AM
well, now, which fets? for the mosfets, you can use 2N7000 or BS170, maybe VN10K. try all three! whichever you buy, get the datasheet and check yr pinouts! (and the last mosfet stage of the last posted version still needs some dc bias, to my eyes.)

as for the jfets, just about anything you can lay your hands on. J201 and 2N5457 are the most popular. they will both sound different. you can also try 2N5458, 2N5484 or 5, BF245A or B, 2N5952 or 3, 2SK30 and loads of other 2SK-types, many others.

some of those are backwards to the others, so you gotta get the datasheet to know for sure. good luck and welcome to the forum.

Hi..
Farely new to the forum ... So much info all over the place that I most of the time find the right answer  ;D

I'm giving the BF5 a try ... and I have 2SK30AY's at hand.. but the info about the pinout of these that I've found is moslty SGD, but also DGS.
here it says SGD:
http://www.diystompboxes.com/smfforum/index.php?topic=7497.0
and here DGS:
http://www.diystompboxes.com/smfforum/index.php?topic=54614.0
 I've also read that "90% of the time" S and D are reversible.. I measured them with a DMM using this method (found it somewhere around here, just don't remember where):
" ------ 2. For JFETs: Drain and source conduct to each other both directions. Gate conducts to both drain and source one direction (junction forward biased) and not at all in the reverse direction (gate reverse biased). There is a 90% chance that drain and source are interchangeable. ------ "
My K30's read " K30AY  8B" .. Any way to know who the manufacturer is ?

Saludos from Mexico.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: duck_arse on July 11, 2014, 09:12:36 AM
I would say hello in spanish, but I'd just spell it wrong and look a goose. hello, verr, and welcome.

if you go here:
http://www.datasheetcatalog.com/

they have a load of manufacturers trademarks showing. see if your fet has anything that matches. either way, get your datasheet for 2sk30, they should all be the same. I think it's gate centre, no? there is a thread hereabouts about the interchangeabillity of drain and source, you can search that.

for our purposes, sgd = dgs in this instance.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: candletears7 on July 15, 2014, 12:51:52 AM
Hi guys, I've got an etched board of the layout on page 1 of this thread.
Is this layout verified?
Any changes?
Keen to get into this.
And thanks for all the work on it!  :icon_smile:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Singulano on August 23, 2014, 06:50:01 PM
Version 5 of Uberschall tested and highly aproved!
Live is much better than the video. And a little tip. The Voice Pot works better for me being 20KA.
Thanks a lot, J0K3RX!!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Singulano on August 23, 2014, 06:51:31 PM
https://www.youtube.com/watch?v=rM_3h6TnAOA&list=UUUwEIqPJirqqnKe85ggspRQ (https://www.youtube.com/watch?v=rM_3h6TnAOA&list=UUUwEIqPJirqqnKe85ggspRQ)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on August 23, 2014, 09:23:01 PM
https://www.youtube.com/watch?v=rM_3h6TnAOA&list=UUUwEIqPJirqqnKe85ggspRQ (https://www.youtube.com/watch?v=rM_3h6TnAOA&list=UUUwEIqPJirqqnKe85ggspRQ)

Singulano - Great demo!! Good work! :icon_wink:

Nice for a change to see somebody make a demo clip!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on August 25, 2014, 04:18:37 AM
J0K3RX,
DId Arzone make this layout available? I made your 1590B Triple Wreck and I would love to build this one also.

Cody

Yup! I gots it... Ya want it? :icon_mrgreen:
Can I get the arizone Layout as well? And that Triple Wreck would be nice too. :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Darksid on August 26, 2014, 03:46:37 AM
Prompt scheme 1posta final or have any mod.Zhelayu collect myself ...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: tech9_79 on August 29, 2014, 07:14:26 PM
hey joker could i nab the blackforest layout from ya?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Singulano on September 03, 2014, 09:34:47 PM
https://www.youtube.com/watch?v=rM_3h6TnAOA&list=UUUwEIqPJirqqnKe85ggspRQ (https://www.youtube.com/watch?v=rM_3h6TnAOA&list=UUUwEIqPJirqqnKe85ggspRQ)

Singulano - Great demo!! Good work! :icon_wink:

Nice for a change to see somebody make a demo clip!

Thanks man!! Great preamp you did!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on September 04, 2014, 04:30:31 AM
slightly of topic sorry jim, , but what string gauge would you guys recommend for drop B on a bog standard guitar

so the lowest isn't flabby?...i just want drop B  to match my 5 string bass.. 8)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: JebemMajke on September 04, 2014, 06:50:32 AM
I can suggest you two types.

Fender 13-65 - baritone, really nice lows, chung chung riffs. The only low point is that the difference between 3rd and 4th string is too big. I used to swap it's 4th string ( 20 ) with something like 27 or 32.

Dean Markley 13-56, really nice low mids, not as much low growl as with fenders, but pretty decent. Way better than just down tuning a 9-42 set.

I had a really bad experience with Zakk Wylde Dunlop set, 10-60, to much mud in the sound ... and the 10.13.17 were really hard to tune correctly
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on September 04, 2014, 01:03:09 PM
cheers misa, i'll try the 13-56's then as a start off  \m/  :icon_twisted: \m/

 8)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: wgc on September 28, 2014, 06:46:28 PM
Hey all

I usually hang over at madbean. But here's where I saw this first, and figured it probably belongs here at the least.  Plus I've never really posted in a 50 page thread. Exciting!

here's an smd layout & build I did of the blacker forest. Yes, I spelled vicous wrong.  No, I didn't intend to.  I was just so excited to be laser etching. 

I also etched the tone stack knobs in backwards order.  Ah well.

Mispelling and graphic layout were the least of my challenges on this one.

I did the box ages ago, when I first saw Jim's post elsewhere about the jfet uberschall.  I intended to build it using an etch for through hole parts, but I just never got a good etch.  Time marched on. 

I started doing other things, and recently felt confident enough in my layouts to do an smd version of  his circuit. While I was at it, I decided to combine the boost and the mids mods into one switch so they would come on at the same time for leads.  Went pretty well over all.

Got the pcbs made, and populated, and then it didn't work.  Turns out  that during my layout shenanigans I used a bad pinout on the jfets, but  fortunately, I could just rotate them mismatched to the pads. 

Then it fired up!  And sounded amazing!! 

But the squeal...  dear lord, the squeal, it was heart rending.

I tried all kinds of things.  Shielded cable, cap changes, resistor changes, buffers, etc.  A few things helped but nothing fixed it.  I thought, "maybe I routed those traces too close. Maybe I shouldn't have used a ground plane.  Maybe the ground plane should have only been on one side of the pcb."  All kinds of things went through my head, on multiple nights, at 2am. Or later.

Then while I was in there swapping out caps, I realized I put the treble pot where the bass pot should be.  So I decided to move it and boom.  There it was.

I made this layout to match the box (almost), which I had previously stuffed with pots and a footswitch.  But I never checked the values of the pots once they were in.  Turns out they're from an earlier version of the schematic, not the one I used to do my layout.  Damn it! 

Changed them to match the schem I used for my layout and now most of the oscillation is gone. I still get some at the extremes of vol settings but its so much better...

I might update this pcb (and the box) when I get a chance since there's a few things I'd change now that I'm older and very little wiser, but overall I'm pretty happy with it! 

(http://i1194.photobucket.com/albums/aa361/wgc2005/Guitar%20stuff/viscious/visciousbf03.jpg)

(http://i1194.photobucket.com/albums/aa361/wgc2005/Guitar%20stuff/viscious/visciousbf02.jpg)

(http://i1194.photobucket.com/albums/aa361/wgc2005/Guitar%20stuff/viscious/visciousbf01.jpg)

Awesome job, Jim, love this one!  It sounds killer with a tube screamer at low settings in front of it.

Thanks for looking, have a great weekend...!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 28, 2014, 08:46:18 PM
(http://i1194.photobucket.com/albums/aa361/wgc2005/Guitar%20stuff/viscious/visciousbf01.jpg)

It sounds killer with a tube screamer at low settings in front of it. <---  :icon_twisted: Oh Yeah!


That looks Feckin Awesome duder!!  :icon_twisted: I have to say that board looks a hell of a lot better than I expected!! :icon_wink:  The whole thing looks wicked good!
And now for the drum roll......................................................................Audio Demo :icon_wink:

Must tell me more bout the laser etching!? Did you build it...? I have some lasers that I have been playing around with but aside from burning wood and holes in my neighbors siding it hasn't found a useful purpose, yet.  :icon_cool:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: wgc on September 28, 2014, 08:58:19 PM
Ha!  Thx man, great circuit! 

I gotta get a way to record stuff. Too busy building.  But I'll get one up sometime. 

I'm lucky we have a laser at work(not built diy), great fun but also a pita when things don't go well. This was a pretty early one, around page 12 of the thread.  Also we have others who tweak things (not for the better) and I often forget to check.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 29, 2014, 12:37:45 AM
Billy,

In regards to the unwanted squeal, hiss, hum etc that plague these high gain builds..

Probably nothing you and most others here weren't already aware of but, it really makes me wonder sometimes when I see these pcb circuits jam packed into these tiny enclosures or some of these vero boards that have components scattered all over the place with excessive wires etc... 

Besides the obvious circuit design problems, the pcb layout makes a big difference with noise and that is especially true when it comes to these high gain pedals! Many who have followed this post from the beginning know that I am guilty of this myself and have wasted probably hundreds of needless hours swapping parts and chasing ghosts in my builds...  :icon_rolleyes: Live and learn.. Now I am at least aware of it and keep it in mind when I am making a layout.

Quote from "indyguitarist" Brian Wampler:

"I didn't use to believe it, but after testing it myself I found out several years ago that the layout can totally change the feel, sound, and noise level of a circuit.
We experimented quite a bit with layout practices and came across sort of a 'formula' for lack of a better word. Plus, I send my layout guy to some extremely high-dollar courses for EE's that discuss nothing but layout in the audio electronics field. Expensive, but worth it. Sorry I can't give away any tips, but trust me when I say that layout does indeed matter."   


There is plenty of documentation on this subject if you do a google search...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: wgc on September 29, 2014, 09:20:28 AM
Totally agree- I learned a lot on this one. 

I have my in/out pretty close together on the pcb. Also the ground pour can influence capacitance-I did top and bottom, figured it would help with noise.

But the 3pdt is probably the area that could stand the most improvement.  My std 3pdt wiring puts in/out right next to each other.  In the future, I'd move them to the outside and put the led in the middle. I suspect lots of whine in high gain boxes might be improved by changing the switch wiring.

Aside from all that the biggest improvement was the cap I put in series with r2 at the input. Get rid of the higher freq no one can hear anyway, and there's less of those around to contribute to oscillation.   But it can also change the sound if you're not careful.

I may try changing the volume pot just to see what happens, but for now, I'm leaving it alone.

Anyway, I posted mistakes and all in the interest of helping others avoid or repair similar issues. This is way too cool a circuit to leave in the box of fail..!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Singulano on March 25, 2015, 11:43:34 AM
Hi Guys, back here. I´ve made the "Engl 3" of the 14th page and it´s working nice!
Thanks J0K3RX again!
Pretty soon i'll post a test vídeo.
The treble pot was too high for me, so a added a 3-way switch to add another 220p cap or a 470p cap in parallel with the 220p cap in the project. Now I have 3 different voices on the pedal. And the sweep pot, I changed for a trimmer, because don´t seems to be necessary to me always tuning him.  ;D
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 26, 2015, 02:55:37 PM
Hi Guys, back here. I´ve made the "Engl 3" of the 14th page and it´s working nice!
Thanks J0K3RX again!
Pretty soon i'll post a test vídeo.
The treble pot was too high for me, so a added a 3-way switch to add another 220p cap or a 470p cap in parallel with the 220p cap in the project. Now I have 3 different voices on the pedal. And the sweep pot, I changed for a trimmer, because don´t seems to be necessary to me always tuning him.  ;D


Singulano - the Engl is one of my favorites! I have more mods since I posted that... Would like to hear yours!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Cozybuilder on March 26, 2015, 03:34:18 PM
Hi Jim- Any chance you will post an updated schematic?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on March 27, 2015, 10:25:35 PM
Hi Jim- Any chance you will post an updated schematic?

Perhaps... What did you have in mind?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Singulano on March 30, 2015, 02:29:00 PM
(https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xpa1/v/t34.0-12/10881512_764565676984654_6309330486356737928_n.jpg?oh=d802b73cd0b85be86281b13f8a29bd1b&oe=551B7703&__gda__=1427860949_5f11c46d9141f630c289d00192e8f3f7)
This is the box. Soon I'll made a vídeo test, exploring the adjusts.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: slipknot55566618 on April 19, 2015, 03:56:14 PM
I finished assembling the Blackforest today excellent pedal, high gain without excessive distortion , thank J0K3RX

greetings from Brazil  :)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Singulano on April 28, 2015, 05:48:01 PM
Some mods I've done for the Engl 3
Q1= 2N5457
Q5/Q6= 2N5458
Bass pot= 1MA, for better response.
Change the 4n7 cap, that limited the bass, to 22n or other... if increase too much, the sound could tangle.
Change the 220p cap above the treble pot to 370p, to add mid/treble frequency. 220p makes the treble pot add just very high frequencies.(Dimebag fans could like this way)
Soon I have time, I'll post a vídeo test.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Singulano on June 10, 2015, 06:19:16 PM
A little test... cheap Condor guitar, Engl Preamp, Poulin Lecab 2.

https://soundcloud.com/samuel-singulano/engl-e530-by-j0k3rx (https://soundcloud.com/samuel-singulano/engl-e530-by-j0k3rx)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on June 10, 2015, 10:19:27 PM
A little test... cheap Condor guitar, Engl Preamp, Poulin Lecab 2.

https://soundcloud.com/samuel-singulano/engl-e530-by-j0k3rx (https://soundcloud.com/samuel-singulano/engl-e530-by-j0k3rx)

Sounds pretty good man!! I have to say it really kinda freaked me out when I listened to it! I clicked on the link, it started playing and I got a phone call and muted the volume. I got off the phone, turned the volume back up and the AMT Pangaea demo had started playing and I thought it was still the Engl :o  :P  :o.....Wooooh :icon_lol:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bamslam69 on June 05, 2016, 11:39:05 PM
This sounds like the ideal pedal to fill a spare 1590BB box I have.
Jok3rx, can I clarify that the Blacker Forest - No return Version 5 schematic (found on page 41) is all good?

Feeling pretty optimistic for a 2nd pedal build. :)

Ps. was there a schematic for the Engl box from Singulano's recording? That sounds epic!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Singulano on June 07, 2016, 07:26:58 PM
bamslam69, the Engl details is in the page 14  ;)
That pedal is great, I've made 2 for me  :icon_cool:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bamslam69 on June 07, 2016, 09:03:50 PM
Thanks heaps, Singulano.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on June 07, 2016, 09:18:18 PM
Yeah, reply# 817 on page 41 should be good to go.. Been a while since I looked at all of them :icon_rolleyes:

The Screamin Eagle (ENGL) is the gtlab.net / guitarjfet.ru design with some minor changes and mods that I added along the way...

All files including the Sprint layout files can be downloaded here..
https://www.dropbox.com/sh/m1u88kbmpavqmxa/AAB-EqzwuripkZM7uDqVJqPwa?dl=0

(https://dl.dropboxusercontent.com/u/11178619/SCREANIN%20EAGLE%201/Final/SE-1%20On-Board%20Noise%20Gate_small.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: blackieNYC on June 07, 2016, 09:58:15 PM
Hey J,
That entry 817 is a layout.  There is a schematic on that page in 805 and it has the add-on circuit. So you have the Black Forest, the Black Forest No Return with the added output stsge, and the Blacker Forest. The Screaming Eagle is something else altogether, right?
For whatever reason, I enthusiastically put "Blacker Forest" on my build list. I thought I kept a link for that somewhere.  I hate to ask an author for the Cliff Notes version, but could you give me a "JOK3RX for Dummies" rundown of these above schematics and what you think of them? Is this a project that has branched off into a few successful projects, or has this (to you, not neccesarily to our collective) evolved into one Final?
Thanks for these awesome designs, bro!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bamslam69 on June 07, 2016, 10:08:04 PM
Oh wow, thanks heaps Jok3rx.
I'll check out all the sound files tonight.
I've only etched a pcb once a long, long time ago, so this will give me the incentive to relearn it all.

[too many things on my to-do list]


Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Zilla on June 09, 2016, 04:41:34 PM
J0K3RX,

This thread is awesome! you'd done some awesome work with this!

i have a question regarding the screaming eagle schematic above.

Lug 1 on the gain pot and quite a few other components are shown to go to 4.5V.

if i look at another schematic like the Dr. Boogie all of these components are going to ground.

is this right? why would your schematics show it going to supply/2 ?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bamslam69 on June 09, 2016, 07:32:23 PM
Joker Do you have a photo of a completed Screaming Eagle? I'm just interested to see if you've added all those options and how you accommodated them in the enclosure.
Cheers

Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 13, 2016, 11:17:23 PM
It's gettin close to Halloween so, I thought I would get out my gravedigger shovel and exhume this rotting, decomposed corpse of a topic  :icon_twisted:

Over time, a lot of people have messaged me asking various questions about the Screamin Eagle and some of the other FET preamp pedals.. I came across this not long ago and thought it was interesting! Also, it looks like nearly all of his builds are on vero which is not really my thing but, he really pulls it off well and his boxes sound pretty damn good! Dude can really chunk out a mess of vero builds at one time!  :o

Website
http://mastereffects.wixsite.com/mastereffects





Another guy who built the Screamin Eagle



And just for good measure a little 3-string shovel slide geetar... 
cause gravediggin is a hole lot more funner with some good old shovel geetar  :icon_twisted:


If ya ain't got a spare shovel then just grab ya a stiff 2x4, an old bass string an make ya one of these here djent sticks :icon_evil:



Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: blackieNYC on October 13, 2016, 11:35:40 PM
Excellent!
J- could you steer me to the schematics I mention just above in reply #1006?
I've seen three black forests, and I'm wondering if these were revisions or improvements for you.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: 287m on October 14, 2016, 03:01:07 AM
oops
i think when open this thread, J0K3RX launch the missile BF6  :icon_evil:
 :icon_mrgreen:

Excellent!
J- could you steer me to the schematics I mention just above in reply #1006?
I've seen three black forests, and I'm wondering if these were revisions or improvements for you.
you want this? this is BF5. i hope J0K3RX give me the blessing permission  ;)
(https://1.bp.blogspot.com/-hWLI011z2aw/WACBYBAkM1I/AAAAAAAAA7w/uxU9bHZzTDYeqFKhGC_PcuhbxPpuyF56QCLcB/s1600/BF5_sch.jpg)
for the layout all onboard pots, just shoot ask J0K3RX  :icon_redface:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Nas on October 15, 2016, 04:09:26 AM
Hey all:

Does anyone have a Randall Satan repair schematic you could PM me or send me a link to? Thanks.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 15, 2016, 07:23:16 AM
Hey all:

Does anyone have a Randall Satan repair schematic you could PM me or send me a link to? Thanks.

Nope... I wish I did!  I can say that it sounds a lot like the Fortin Hulk.. Same controls like Grind, Girth and Sweep etc.. I have the Hulk schematics that have been floating around the internet for the past couple years. They may not be 100% but, they are close enough and sound damn good! A lot of people think it's close to the Elan Metalhead also, maybe a combination of the two..? I think the satan/thrasher has more of a Marshall type tone like the Hulk but that's just my opinion.

If there is a satan schematic out there you can bet I WILL find it!! But no luck so far.. :icon_evil:

Are you asking because you have a broken one on your bench? :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Nas on October 16, 2016, 06:42:51 AM
Are you asking because you have a broken one on your bench? :icon_twisted:

Unfortunately :-\

If you have a link to that Hulk Schematic, that'd be great. (And if you ever find the actual schematic, I'd certainly appreciate it. Thanks, J0K3RX!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 16, 2016, 06:53:04 PM
Are you asking because you have a broken one on your bench? :icon_twisted:

Unfortunately :-\

If you have a link to that Hulk Schematic, that'd be great. (And if you ever find the actual schematic, I'd certainly appreciate it. Thanks, J0K3RX!

Unfortunately yes you do have a broken one on your bench or no you do not have one on your bench? :icon_confused:

Hulk
https://dl.dropboxusercontent.com/u/11178619/Fortin/Fortin%20Hulk.png
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 16, 2016, 07:12:44 PM
Here is the Black Forest rev.6 and for this demo (and probably every demo going forward) I used DI tracks :icon_twisted:
I used a TS808 in front of the BF6 and some tight reverb, a little EQ and some cab/mic impulses on the tracks..

Killswitch Engage - Rose Of Sharyn DI
https://dl.dropboxusercontent.com/u/11178619/BF6/BFRev.6-TheFog-RoseofSharynDI-2.mp3
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Nas on October 16, 2016, 09:48:27 PM
Unfortunately yes you do have a broken one on your bench or no you do not have one on your bench? :icon_confused:

Hulk
https://dl.dropboxusercontent.com/u/11178619/Fortin/Fortin%20Hulk.png

Unfortunately, yes :(
Thank you for the Hulk schematic! Hoping this can do the trick.

And if you ever find that Satan schematic, please let me know. Btw, that Black Forest rev.6 demo you posted sounds great!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: deadastronaut on October 17, 2016, 03:40:45 AM
sounds pukka!!! :icon_twisted: :icon_twisted: :icon_twisted:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: caspercody on October 17, 2016, 02:50:29 PM
Hey JOK3RX,

Do you have the Rev 6 schematic?

Also, once I read you mention that the Sansamp once your favorite amp emu pedal out there. Do you still believe they are? And if not, what pedal(s) do yo feel are the best amp emu?

Thanks
Rob
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on October 17, 2016, 06:23:23 PM
Hey JOK3RX,

Do you have the Rev 6 schematic?

Also, once I read you mention that the Sansamp once your favorite amp emu pedal out there. Do you still believe they are? And if not, what pedal(s) do yo feel are the best amp emu?

Thanks
Rob

Rob,

Yes, I have the rev 6 schematic.

Yes, I believe I said the "SanAmp Classic" was one of the best and yes, I still think it is one of the best, that is my opinion, of course. I still have a hard time believing that somebody actually reverse engineered one of the "Classic" pedals and the clones that I heard did not sound the same.. I had a SansAmp Classic and that thing was gooped bullet proof in some sort of epoxy and sandwiched between 2 pieces of white porcelain. No way anybody was able the get through that!

~ Jim
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: caspercody on October 17, 2016, 08:46:27 PM
Thanks for your reply about the Sans amp!

Any way to see the Rev 6 schematic?

Thanks
Rob
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: briandress on March 23, 2017, 06:14:28 PM
i would love to see this schematic too!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Hunter on July 04, 2017, 08:56:17 PM
Good evening.
I need a valid schematic of the BF5. Could someone please share?
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bamslam69 on July 04, 2017, 09:02:28 PM
Hey Hunter, I asked this a year ago (previous page)... this pedal is still on my to-do list.
Here is J0k3rx's reply. FYI.
Cheers

Yeah, reply# 817 on page 41 should be good to go.. Been a while since I looked at all of them :icon_rolleyes:

The Screamin Eagle (ENGL) is the gtlab.net / guitarjfet.ru design with some minor changes and mods that I added along the way...

All files including the Sprint layout files can be downloaded here..
https://www.dropbox.com/sh/m1u88kbmpavqmxa/AAB-EqzwuripkZM7uDqVJqPwa?dl=0

(https://dl.dropboxusercontent.com/u/11178619/SCREANIN%20EAGLE%201/Final/SE-1%20On-Board%20Noise%20Gate_small.jpg)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Hunter on July 04, 2017, 09:13:40 PM
The link is invalid! There are no more files hosted there.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: bamslam69 on July 04, 2017, 11:08:46 PM
Can't check it from the work pc. but there might be a veroboard layout over on tagboardeffects.blogspot
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on July 05, 2017, 03:33:32 PM
http://www.aronnelson.com/gallery/main.php/v/J0K3RX/BF5_sch.jpg.html
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Hunter on July 05, 2017, 03:49:10 PM
http://www.aronnelson.com/gallery/main.php/v/J0K3RX/BF5_sch.jpg.html

Thanks
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: statzern on September 14, 2017, 10:38:02 AM
Anyone has the PCB etch PDF that goes with this layout file?

J0k3rx, I really like these modular type PCBs you've designed for these. Nice job man!

(https://s26.postimg.org/ncw8umnkl/Layout.jpg) (https://postimg.org/image/ncw8umnkl/)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: J0K3RX on September 14, 2017, 10:52:44 AM
Anyone has the PCB etch PDF that goes with this layout file?

I posted a link to the etch transfer pdf file along with the link to the image in the Screamin Eagle post. You have to click on the tiny "Download document" hyperlink...
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: statzern on September 14, 2017, 02:01:50 PM
I'm sorry, I posted the wrong picture!! I meant this layout... I'm an idiot...



(https://s26.postimg.org/usy5wn0lx/IMG_0207.png) (https://postimg.org/image/usy5wn0lx/)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: statzern on September 16, 2017, 06:13:50 PM
I made my own PCB layout from the above image, here is link for download if anyone is interested.

https://www.dropbox.com/s/0fi2tyrjv97ta4g/Bogner%20Uberschall%20PCB%20Transfer.pdf?dl=0 (https://www.dropbox.com/s/0fi2tyrjv97ta4g/Bogner%20Uberschall%20PCB%20Transfer.pdf?dl=0)
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: temol on October 17, 2017, 03:26:59 AM
This is my version of BF rev5. PCB I made is 114mm wide and barely fits into the enclosure (slightly larger than 1590BB) :(


(http://jackrabbit.pl/foto/upload/2017/10/17/20171017072818-8648b38d.jpg)

(http://jackrabbit.pl/foto/upload/2017/10/17/20171017072757-d09043ea.jpg)

(http://jackrabbit.pl/foto/upload/2017/09/04/20170904234853-da2ff162.jpg)

T.


Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: temol on October 19, 2017, 03:13:44 AM
Yesterday I played through BlackForest for a while. Sounds very powerfull, but one thing amazes me.. there is virtually almost no noise.. no hum.. even with gain at maximum. I had to make sure it's on.. I hope it's not broken :)

T.
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: temol on October 19, 2017, 05:33:16 PM
OK, it's me again..

Short recording, excuse me this lame playing. I`ve tried to reproduce bogner uberschall preset from pod hd500x. Of course using BF. My signal chain - guitar, pod/BF, audio interface, reaper with cab IR loaded.
sample #1 - BF on both channels, cab impulse response ON, touch of reverb.
sample #2 - pod hd500x on R channel, BF on L channel, cab impulse response ON, touch of reverb.
sample #3 - pod hd500x, IR ON
sample #4 - BF, IR ON
No furher processing.

(http://www.jackrabbit.pl/foto/upload/2017/10/19/20171019231226-d93c118e.jpg)
And soundcloud link (https://soundcloud.com/user-275816837/uberschall-kinda)

T.

 
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: Singulano on December 11, 2017, 07:33:43 PM
Hey guys, long time but remember to back here... I relived a forgotten BF5 yesterday and still sounds good to me. The Engl so the same...

Yesterday I played through BlackForest for a while. Sounds very powerfull, but one thing amazes me.. there is virtually almost no noise.. no hum.. even with gain at maximum. I had to make sure it's on.. I hope it's not broken :)

T.

Yes, almost no noise!  :icon_biggrin:
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: fragresist on April 23, 2019, 05:04:02 AM
Hello all!

I'm a newbie in electronics but I really want to build an uberschall (Blacker Forest) preamp. Could anyone tell me what the 'VOICE' potentiometer (in the BF5 schematics) does, because I can't figure it out?

Thanks in advance. Cheers!
Title: Re: BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall
Post by: temol on April 23, 2019, 05:34:35 AM
It's a "variable" slope resistor in a tone stack. Detailed description of the tone stack is here (https://robrobinette.com/How_The_TMB_Tone_Stack_Works.htm). Also try this (http://www.guitarscience.net/tsc/marshall.htm). You can visualize it's (voice) action by adjusting value of the R1.


T.