BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall

[J0K3RX]

@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...

[J0K3RX]

Anybody see anything wrong with this schematic??? 

[GSmith]

Hi guys! No capacitor in parallel with 9v ?

[Ice-9]

@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.

[jymaze]

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.

[GSmith]

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?

[Pojo]

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.

[jymaze]

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!

[J0K3RX]

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

FYI - You better stock up on 1u caps if you're gonna build it... This is loaded with them!

[jymaze]

Maybe you should do some voltage readings around the semi-conductors and post them? This thing should work and have insane gain!

[frankenfurter]

Hi Jok3rx,
really awsome work!!! Which BF schematic would be the latest?
Cant wait to build this thing!

[DEVASTATOR]

can i use 2sk170 transistors , for this preamp ?

[j2sip]

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!

[J0K3RX]

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? Got a link? 

[J0K3RX]

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!

Schematic
https://dl.dropboxusercontent.com/u/11178619/BF5/BF5_sch.jpg

youtube
https://www.youtube.com/watch?v=3HjxeRFr2hI

[pakrat]

That's a nice compact layout. It's good to see this project is still alive, guess I need to give it another try 

[selfdestroyer]

J0K3RX,
DId Arzone make this layout available? I made your 1590B Triple Wreck and I would love to build this one also.

Cody

[J0K3RX]

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?

[selfdestroyer]

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?

Perty Please. I am itching to start a build tonight.

[J0K3RX]

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?

Perty Please. I am itching to start a build tonight.

Check yer email...   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!