Hi all!
About 2 months ago, I posted a thread showing how I transformed a BSIAB into an universal guitar preamp for DI applications. Now that I have received all the PCBs and the components, I'd like to share pics the build of a single channel preamplifier for my home studio. Of course, the module presented here can also be used in multi-channel configurations, for live use.
A short presentation can be downloaded here:
:icon_exclaim: http://www.techniguitare.com/projets/ChaosPreamp/infinity_en.pdf
And the schematics of Infinity here:
:icon_exclaim: http://www.techniguitare.com/projets/ChaosPreamp/Preamp-Schems-V1.1-En.pdf
This youtube video shows the first prototype, and contains some samples:
:icon_exclaim: Here! (http://de.youtube.com/watch?v=BRB0erDUqHU)
And here are 2 additional samples (sorry for the sloppy playing):
:icon_exclaim: Vox style (http://www.techniguitare.com/projets/ChaosPreamp/vox_mix.mp3)
:icon_exclaim: Comfortably Numb (2nd solo) (http://www.techniguitare.com/projets/ChaosPreamp/pink_floyd_comfortably_numb_mix_delay.mp3) (delay added through Audacity).
I'll add the layouts and the bill of materials later, as I am verifying the printed PCBs through this build.
Finally, here are some photos of:
:icon_exclaim: the prototypes
(http://img56.imageshack.us/img56/2407/fullnv1.th.png) (http://img56.imageshack.us/my.php?image=fullnv1.png)(http://img155.imageshack.us/img155/804/cmpsidewe7.th.png) (http://img155.imageshack.us/my.php?image=cmpsidewe7.png)(http://img529.imageshack.us/img529/6927/coppersideqf1.th.png) (http://img529.imageshack.us/my.php?image=coppersideqf1.png)
:icon_exclaim: the current build (beginning)
(http://img4.imageshack.us/img4/5982/pcballtb0.th.jpg) (http://img4.imageshack.us/my.php?image=pcballtb0.jpg)(http://img5.imageshack.us/img5/8640/pcbmainen0.th.jpg) (http://img5.imageshack.us/my.php?image=pcbmainen0.jpg)(http://img11.imageshack.us/img11/15/pcbpsuxm9.th.jpg) (http://img11.imageshack.us/my.php?image=pcbpsuxm9.jpg)(http://img16.imageshack.us/img16/8973/pcbpsumountyv5.th.jpg) (http://img16.imageshack.us/my.php?image=pcbpsumountyv5.jpg)
Stay tuned for updates (as soon as I buy new batteries for my camera ;D).
PS (a bit of advertising): this poject is born on the french forum, www.techniguitare.com . There are many more interesting project, so visit it ;D
Very impressive!
Just finished a quick look at the schematics, looks to be a great build.
Big build.
Huge sound in the clip though !
Thats looking really good, and sounds good also. looking forward to seeing the finished build
Thanks!
And the finished building is one step nearer ... box is drilled and jumpers are soldered on the main PCB.
(http://img407.imageshack.us/img407/8207/boxfrontox5.th.jpg) (http://img407.imageshack.us/my.php?image=boxfrontox5.jpg) (http://img443.imageshack.us/img443/2717/boxrearxa1.th.jpg) (http://img443.imageshack.us/my.php?image=boxrearxa1.jpg) (http://img186.imageshack.us/img186/5934/pcbmainjumpersrk3.th.jpg) (http://img186.imageshack.us/my.php?image=pcbmainjumpersrk3.jpg)
Wow, nice work!
:D
Little update: resistors, sockets, capacitors and the trimmer have been soldered on the main board.
(http://img19.imageshack.us/img19/1853/pcbmainresvk7.th.jpg) (http://img19.imageshack.us/my.php?image=pcbmainresvk7.jpg) (http://img24.imageshack.us/img24/1703/pcbmainsocketsnr6.th.jpg) (http://img24.imageshack.us/my.php?image=pcbmainsocketsnr6.jpg) (http://img26.imageshack.us/img26/5930/pcbmainfullfronthw0.th.jpg) (http://img26.imageshack.us/my.php?image=pcbmainfullfronthw0.jpg) (http://img25.imageshack.us/img25/6856/pcbmainfullrearlu0.th.jpg) (http://img25.imageshack.us/my.php?image=pcbmainfullrearlu0.jpg) (http://img100.imageshack.us/img100/588/pcballmountzy6.th.jpg) (http://img100.imageshack.us/my.php?image=pcballmountzy6.jpg)
Looks like a very cool project! :icon_razz:
I'm going to do something similar with my ADA Flanger clone, as soon as the PCB arrives... :icon_surprised:
Looks really cool! Good job!
:D :D
But now it's getting messy :icon_redface: ... offboard wiring!
(http://img172.imageshack.us/img172/2782/wiringoffboard1cd0.th.jpg) (http://img172.imageshack.us/my.php?image=wiringoffboard1cd0.jpg) (http://img223.imageshack.us/img223/8213/wiringoffboard2ku0.th.jpg) (http://img223.imageshack.us/my.php?image=wiringoffboard2ku0.jpg) (http://img5.imageshack.us/img5/8501/wiringbox1dm3.th.jpg) (http://img5.imageshack.us/my.php?image=wiringbox1dm3.jpg) (http://img5.imageshack.us/img5/2667/wiringbox2os9.th.jpg) (http://img5.imageshack.us/my.php?image=wiringbox2os9.jpg) (http://img18.imageshack.us/img18/5773/wiringbox3nz7.th.jpg) (http://img18.imageshack.us/my.php?image=wiringbox3nz7.jpg)
Messy? Say what?! :icon_wink:
I always have the feeling that wires are running over the place, even if they are cut at approximately the right length ::). Anyway, I made a test with the jacks and PSU on perfboard, and it works pretty well. I am still waiting for the PCB supports, so I'll have to slow down the construction a bit, but I'll post the layout soon, since it's verified.
Here is the PCB:
http://www.techniguitare.com/projets/ChaosPreamp/guitar_preamp.pdf
And here is the parts layout:
(http://img155.imageshack.us/img155/6181/infinitypcblayoutjd8.th.gif) (http://img155.imageshack.us/my.php?image=infinitypcblayoutjd8.gif)
Enjoy :)
Finished!
Here are the last photos ...
(http://img19.imageshack.us/img19/6941/wiringpcball1.th.jpg) (http://img19.imageshack.us/my.php?image=wiringpcball1.jpg) (http://img24.imageshack.us/img24/9020/wiringpcball2.th.jpg) (http://img24.imageshack.us/my.php?image=wiringpcball2.jpg) (http://img26.imageshack.us/img26/5381/wiringpcbpsu.th.jpg) (http://img26.imageshack.us/my.php?image=wiringpcbpsu.jpg) (http://img27.imageshack.us/img27/8426/wiringjack.th.jpg) (http://img27.imageshack.us/my.php?image=wiringjack.jpg) (http://img100.imageshack.us/img100/3306/wiringled.th.jpg) (http://img100.imageshack.us/my.php?image=wiringled.jpg) (http://img153.imageshack.us/img153/3040/wiringcompletezj4.th.jpg) (http://img153.imageshack.us/my.php?image=wiringcompletezj4.jpg) (http://img413.imageshack.us/img413/8393/endoff.th.jpg) (http://img413.imageshack.us/my.php?image=endoff.jpg) (http://img527.imageshack.us/img527/9028/endon.th.jpg) (http://img527.imageshack.us/my.php?image=endon.jpg)
Enjoy!!!
Here is a .zip file with all the photos:
http://www.techniguitare.com/projets/ChaosPreamp/infinity_photos.zip
And, about the transistor biasing, Q5 in the common source stage is biased at 6V.
I'll post the values of Vth and Idss for the transistors as soon as I find the sheet where I wrote them. :P
Quote from: DSV on February 16, 2009, 02:48:38 PM
I always have the feeling that wires are running over the place, even if they are cut at approximately the right length ::). Anyway, I made a test with the jacks and PSU on perfboard, and it works pretty well. I am still waiting for the PCB supports, so I'll have to slow down the construction a bit, but I'll post the layout soon, since it's verified.
Yeah, I know what you mean. But your wiring is far from messy. :icon_wink:
Thanks, Paul ;D (I had completely missed your reply)
And here are some new clips. After listening to them again, here are my impressions:
Two minutes to 2h in the morning (http://www.techniguitare.com/projets/ChaosPreamp/im_aces.mp3): Iron Maiden style. Probably thin. I scooped the mids on this one
Plexi style! (http://www.techniguitare.com/projets/ChaosPreamp/plexi_uh_mix.mp3): maybe a tad too fizzy
Thunderstruck (http://www.techniguitare.com/projets/ChaosPreamp/inf_thunderstruck.mp3): instrument placement ain't that good, nor is playing
Sharp dressed man (http://www.techniguitare.com/projets/ChaosPreamp/inf_sharpdressedman.mp3): difficult to capture the ZZ-Top tone, I tried to do my best ...
Enjoy!
Not to disagree but I disagree, these aren't
thin, The IM was really full of fine 'big guitar' sound !
Plexi style!: fizzy, nope, this one has really cool playing and the mix is a fine example of your wizardry applied !
Thunderstruck: instrument placement ain't that good, nor is playing
Rythms sound really nice thick and grindy, the leads maybe could have used a bit more 'push'.
Sharp dressed man: difficult to capture the ZZ-Top tone, I tried to do my best
Ok you got me on this one. Try playing it through the plexi-style or IM settings, or the rythm tone for the T-struck...they're outstanding, Impressive !
pure awesome :)
also, if it's not too much trouble, could you post the parts list ;D
Wow! Cool...BUMP!
That's at the top of my list of "must-build" list. I'm thinking a 1 RU rack unit enclosure with a rotary/switchable tone stack and an effects loop.
Wow, thanks! :icon_biggrin:
I may make some modifications on the output filters, since treble and bass are always roughly at 75%, and I'd like them centered for a better pot range. Furthermore, in the last 20% of the rotation the bass pot shifts the frequency of the treble one, resulting in a presence loss (this is because the Baxandall is simplified). However, if the previous mod is done, there will be no big need to change the tone controls. And what's good, is that the previous mod can be done simply through a value swap !
Once it's tested, I'll post it.
New sample: Three little pigs (http://www.4shared.com/file/91666767/59c1ff2b/inf_pigs.html) ;D
I fooled around with Audacity this time, by adding some:
- reverb, in the synth-like parts;
- compression, in the bass-like part;
- equalizing, for the "delay effect": one guitar part was copied, delayed i time and then equalized for treble loss.
Compared to the original, the guitar part has too much treble and distortion, it was with my setting for "Have a cigar", nothing that the harmonics and gain pots cannot handle.
Little update!
Here is the block diagram for a 1U Rack project, with 3 channels (the 1st with modes "normal" and "boost").
(http://img145.imageshack.us/img145/7240/infinity3channel.jpg)
I will start it in 2-3 weeks, and will also post some mods for:
- the output filters of the distortion section;
- the bass boost in the pre-EQ for a typical Marhsall response.
what op-amps/transistors are the U1 and U2 in the schematics?
and (stupid question but) does this work as a preamplifier before a "real" amp?
And, how much did it cost to do this in total?
Aaaand, have you tried contacting the output to speaker/headphones? Does it have enough power in the output to make some sound(without extra amplification), enough for practising etc.?
-Peace.
Id have a challenge for ya, if youre interested. Please read to the end even if you dont want to do this.
try to re-create this (http://www.youtube.com/watch?v=WrBLnB3ze5Y&hl=fi) sound.
More specifically, the sound thats played with the 7-string after he has played the white six-string and the other distortion first, then played through the clean channel of the amp with the 7-string(Did i express myself a bit complicated?I mean the sound at 05:31->little while later)
And with the EQ's of your preamp, it would of course be nice to hear the sound before its distorted, and why not the other distortion sound too ;)
Of course you dont have to do any of this, but id be happy If you did. ;D
Opamps are all Tl07x series: TL072 for the dual, TL074 for the quads.
I haven't tried Infinity as a preamp with a traditional speaker cabinet: my Vox AD30 does not have an fx loop :icon_sad: Furthermore, the eq settings would be different for each speaker. However, it is possible to modify the output filters, and in particular the bridged T network (page 3 of the schematics) for optimal post-eq control range.
I tried it as a distortion, but it did lack harmonics imho, even with the cab sim set for the maximum cutoff frequency. I think a switch bypassing it would solve the problem.
About the cost, it was roughly 75€:
- 10 € for the PCB
- 10 € for onboard components
- 20 € for offboard components (pots, leds, jacks, switches, wires)
- 15 € for the box
- 20 € for the knobs (could have been 10 €, but I wanted those cool, small, little aluminium knobs)
(you could count also the 0-18V adapter, but that can be replaced by voltage doublers ... 5€ more)
For a multi-channel version in a rack, I would say 100-150€ depending on the features, the PSU etc.
I would like to take the challenge, but youtube says I cannot see the video in my land !?!?!? Do you have any other link, or title?
Finally, there were some requests for a parts list, now I have the time to make it. I will also post about how to mod the output filters for optimizing the control range.
thats wierd!
ill post you three links to the vid, one to youtube(the very same i linked before, it should be) and the two others to some other places. all found with video.google.com
all (should be)high-quality
http://www.youtube.com/watch?v=WrBLnB3ze5Y&hl=fi (http://www.youtube.com/watch?v=WrBLnB3ze5Y&hl=fi)
http://www.wat.tv/video/steve-vai-jemini-distortion-121rl_u4o5_.html (http://www.wat.tv/video/steve-vai-jemini-distortion-121rl_u4o5_.html)
http://www.veoh.com/browse/videos/category/music_rock/watch/v15936427nP2BP9SP (http://www.veoh.com/browse/videos/category/music_rock/watch/v15936427nP2BP9SP)
Must be some weird stuff from youtube and copyright issues ::) Anyway, the second link works. I'll add some reverb and delay with Audacity in order to have a chorus-like effect, as there is in the video, though I will also post the raw sound. Tomorrow, though ... it's 1AM here :icon_mrgreen:
Looking forward to the final revisions of the schematic/layout.
Here are the samples:
The distortion (by re-listening it, i find there is too much mid content, nothing that the eq cannot scoop though)
http://www.4shared.com/file/96848110/e9dbfb50/inf_gemini1.html
And a bit of noobish guitar playing with distortion 2, something like distortion 1 and clean:
http://www.4shared.com/file/96848265/d4b62741/inf_gemini2.html
Hi
A very impressive an good sounding project. And you seam to be a cruel axe slinger too.
But even more impressive is that card board box with stuff you have on the pic site. Have you ordered all that stuff at one shot????
I haven't managed to use up that much in two years.
//Solderman
Wow!
Quite close! :o
I think there is something lacking from the tone, maybe a real chorus would make it sound a bit closer to the original, and Im not sure what else the tone might lack but stil... wow.
maybe its just that you just cant play like steve vai-nobody other than him can. everyone have their own playing sound, and that might just be the biggest difference im hearing...
was it just the guitar-preamp-PC?
And i think i asked this before, but i dont recall getting a clear answer(might be my imperfect english skills),
so; do you think that if you put a guitar jack to be the output, could the preamp work connected to another amp, like you know as an additional preamp, before the one in the amplifier, or could it be possible to replace an amplifiers preamp with this?
It can be used as a preamp, before a traditional power amp, I wanted it to give an output at line level. I don't know what are the input levels for tube amps, but a gain stage at the end, or reconfiguring the buffer before the tone controls as a booster would imho resolve the issue. I was talking about the speakers in the previous post, since guitar ones do not have a linear response.
About the recording, it is guitar-preamp-PC. I think what is lacking is harmonics: Vai's distortion has a pretty loose bottom end, but is tight in the mids and highs. I had to find a compromise between boosting the lows on the pre-eq and loosing presence/clarity on the other frequencies, since the pick-ups on my Epi V are pretty muddy (they have more of a bluesy soudn than a harmonic-rich content).
And for sure I cannot play like Vai :icon_mrgreen:
EDIT:
Quote from: solderman on April 05, 2009, 06:10:08 AM
Hi
A very impressive an good sounding project. And you seam to be a cruel axe slinger too.
Hi!
Indeed, I torture my guitar when playing ... Hopefully not the neighbors ears, since I paly direct on the pc, with earphones. :icon_mrgreen:
Seriously, I'm flattered, thanks!
Quote from: solderman on April 05, 2009, 06:10:08 AM
But even more impressive is that card board box with stuff you have on the pic site. Have you ordered all that stuff at one shot????
I haven't managed to use up that much in two years.
//Solderman
Cardboard box? Pic site? ??? Have you got a link?
So are you happy with the project now, or will revisions be made?
I still have got to modify the bridged T in the output filters. I'll do some tests next week.
Quote from: DSV on April 05, 2009, 07:29:09 AM
Cardboard box? Pic site? ??? Have you got a link?
I think I missunderstood the Image Shack site logic. I missed the "Image like this one" text ant thought this was yours
(http://img6.imageshack.us/img6/4969/partsgb4.jpg)
//solderman
Quote from: solderman on April 05, 2009, 04:04:20 PM
I think I missunderstood the Image Shack site logic. I missed the "Image like this one" text ant thought this was yours
//solderman
Heh... uhh, that would be mine. It's part of my long-term plan to build a multi effects unit, and is completely unrelated to this topic here. PM me and I'll tell you all about it, or maybe I'll start a topic once I start making real progress. ;)
I can't believe none of you guys think you can play like Vai.
It's not that hard, all you need to do is practice, and that box will teach you everything !
Via is always a real treat to watch, overcomplicating everything every time.
He understands well how to polish comedy routines, I enjoy the reserve he seems to have the capacity to keep at all times.
If I was into dude-noodling like that, I'd want to be the one...he does some super charged A-1 noodling, thats' for sure, tells a guitar-story every time, all the drama and action you could possibly desire, it's fun to be entertained by the vids he's in.
Steve really works that mug too, very expressive.
;D Here is the parts list of version 1.1: http://www.4shared.com/file/98295463/c206ba91/infinity_BOM.html
I have decided not to change the output filters, as after some testing, I like how they are ... but I will post some info on how to modify them to your taste.
thank you
Definitely keep us posted on the 1U version. I have an old 1U computer network hub that I was going to butcher for it's enclosure, and this does seem like the project to use it for...
Hands down the most entertaining Vai video to date. You've got to see and hear this!
http://www.youtube.com/watch?v=nMXlaMiRxDs
.....and three times as good on the triple neck
http://www.youtube.com/watch?v=aiXR9ggRdFI
The problem with those vids...(in my opinion/IMO) Theyre funny for about half a minute.... then they get boring.
No, this video is a real loser: http://www.youtube.com/watch?v=9IrWyZ0KZuk
And this one even worse: http://www.youtube.com/watch?v=6CfEaSmdtGU&feature=channel
Seriously, I think some of Vai's tunes make great orchestral pieces.
OT, but sorry, I am not convinced. Vai's self-important mugging looks to me like a lobotomized mockery of his infinitely more creative ex-boss. FZ is probably rolling over in his grave, saying, "I should have never taught that shmuck the difference between an oboe and a timpani!" Sure, I'll never be 1/100th the player he is, but ability never justifies out-and-out wankery, which is what I think Vai is all about. That masturbatory bit with the whammy makes me think about the contrast with, say, Adrian Belew--another unfavorable comparison IMHO.
Quote from: Ben N on May 31, 2009, 02:03:03 AM
OT, but sorry, I am not convinced. Vai's self-important mugging looks to me like a lobotomized mockery of his infinitely more creative ex-boss. FZ is probably rolling over in his grave, saying, "I should have never taught that shmuck the difference between an oboe and a timpani!" Sure, I'll never be 1/100th the player he is, but ability never justifies out-and-out wankery, which is what I think Vai is all about. That masturbatory bit with the whammy makes me think about the contrast with, say, Adrian Belew--another unfavorable comparison IMHO.
I agree that Vai sometimes gets a little crazy with the whammy bar, but I think he is a very expressive player, and that appears to some people to be "wanking" and "unmelodic". I suppose I could be accused of the same things as well from anyone who has heard all of my tunes.
Whether you want to acknowledge it or not, he is a virtuoso. Even Frank Zappa said this of Vai. I feel that Frank Zappa wasted his talent on writing tasteless songs, he could have been SO much more. I did enjoy his 3-album set "Shut Up And Play Yer Guitar", though. In
those moments he shined for a fleetng instant. And he always had the greatest gnarly guitar tones.
Quote from: Paul Marossy on May 31, 2009, 02:58:09 PMWhether you want to acknowledge it or not, he is a virtuoso.
Agreed, absolutely. I don't think this contradicts anything I said, although we obviously disagree (respectfully) about the artistic merits of Vai's music-making, as opposed to the technical quality of his playing. BTW, Paul, from what I have heard of your playing, I would not apply any of the above criticism to you. FWIW.
I should also note that while I generally hold shredders suspect, there certainly are many who I think are quite worthy.
Quote from: Ben N on May 31, 2009, 05:52:57 PM
Quote from: Paul Marossy on May 31, 2009, 02:58:09 PMWhether you want to acknowledge it or not, he is a virtuoso.
Agreed, absolutely. I don't think this contradicts anything I said, although we obviously disagree (respectfully) about the artistic merits of Vai's music-making, as opposed to the technical quality of his playing. BTW, Paul, from what I have heard of your playing, I would not apply any of the above criticism to you. FWIW.
I should also note that while I generally hold shredders suspect, there certainly are many who I think are quite worthy.
Woo hoo! I'm off the hook. Whew. :icon_wink:
That's cool. I don't feel that everyone has to agree with my viewpoint, and vice versa. That being said, I have to be in a certain mood to listen to Vai's music. And the same for Yngwie Malmsteen. While I can get into his music, and can appreciate what he does, I can only take it for so long before it wears me out! :icon_lol:
Hey Daniele...
This Infinity preamp looks great! ;D Now I have a couple of questions for you.
I am planning on building my own combo box using Infinity as a preamp and adding a TDA power amp (I'm still trying to decide between a 35W TDA2052 and a 70W TDA7294).
So my typical application would be:
Guitar --> Infinity --> Power amp
I know I should have no problems with that. The thing is, sometimes I will also want to stick my 'ZOOM Digital FX processor' between the guitar and the preamp. Like this:
Guitar --> Zoom Processor --> Infinity --> Power amp
So my questions are:
1. I know the Zoom Processor already sends a line level output signal, which is going to be connected directly to the Infinity preamp. Will I burn or overload the preamp or is it Ok to do that?
2. If the above is ok, I will still want to use the Eq features of Infinity, but bypassing the distortion in order to leave all the distortion process to my digital box. Is there a way to add a bypass switch for the distortion section and leave a clean preamp? (remember, I still want to keep the Eq)
THANX!
Hi off1,
Is your processor one of the Zoom G1 -> G9.2tt family? If so, you can set the output level appropriately. A too great level will not fry the circuit, but will cause distortion in the gain stages.
If the Zoom will be used for distortion, this is the signal path I'd suggest:
Guitar -> Zoom -> Infinity post-eq (basically from the buffer opamp in the Baxandall tone control).
The pre-distortion equalization part would be redundant, unless you would use it to shape the distortion grain as in the Infinity module:
In this case I'd do
Guitar -> Infinity pre-distortion eq -> Zoom -> Infinity post-eq (basically from the buffer opamp in the Baxandall tone control).
In both these cases the distortion section will not be used, which means you can work with higher level signals without having to worry about distortion. The power supply will just have to have enough headroom, and I think anything more than a +/-9V will be OK.
---
BTW, since I bought a bass guitar and am building a pre for it, the 1U project is gthering dust and lacking funds. What I decided is to start the study of a version 2, which will have less controls, more similar to those of a guitar amp, but as effective as the old ones. I'll keep you informed as soon as the specs will be a tad more defined.
Daniele,
Thank you very much for your quick reply. I will use your preamp from the post-eq when I connect the ZOOM box.
I have a slightly older ZOOM box, the 606, but I guess I can use the PATCH LEVEL control to adjust it's output volume.
Really, Thanks a lot!
This is, at first sight, the best project I have found online (and believe me, I've been looking around a lot).
Hi,
I'm just completing items for this project, bacause it just seems to be the solution i was looking for for ages, sounds great!. :icon_twisted:
I presume this preamp has some kind of cabinet simulation in its circuit, videos are recorded drect from its output?
I'm curious about one thing. I would like to make additional outputs for using it in this cases:
- Preamp in front of poweramp (so that i could just connect the output somewhere in the middle to bypass the cabinet simulation)
- overdrive (possibly bypass some filters and use only the distortion to feed the preamp (use it like BSIAB ))
In fact i would make it like that:
1. standard output
2. overdrive pedal output
3. FX out (before cabinet)
4. FX return (to cabinet simulation) - maybe useless but i want to check this out
Maybe the cabinet simulation this is somewhere in the middle, so i would make just a switch bypassing it. I'm just not understanding the circuit in 100%, because i'm rather novice.
Is it somehow possible to do it like i presented? Or just make some switches for this?
(http://img29.imageshack.us/img29/7708/img5872.th.jpg) (http://img29.imageshack.us/my.php?image=img5872.jpg)(http://img15.imageshack.us/img15/6054/img5873b.th.jpg) (http://img15.imageshack.us/my.php?image=img5873b.jpg)(http://img14.imageshack.us/img14/9899/img5876b.th.jpg) (http://img14.imageshack.us/my.php?image=img5876b.jpg)
(http://img44.imageshack.us/img44/1917/img5877t.th.jpg) (http://img44.imageshack.us/my.php?image=img5877t.jpg)(http://img40.imageshack.us/img40/5743/img5878.th.jpg) (http://img40.imageshack.us/my.php?image=img5878.jpg)(http://img36.imageshack.us/img36/8399/img5879i.th.jpg) (http://img36.imageshack.us/my.php?image=img5879i.jpg)
(http://img81.imageshack.us/img81/1423/img5880.th.jpg) (http://img81.imageshack.us/my.php?image=img5880.jpg)(http://img14.imageshack.us/img14/7001/img5881w.th.jpg) (http://img14.imageshack.us/my.php?image=img5881w.jpg)
So I created it. You are the one to encourage me to do my first electronical device!
I'm still waiting for j201 and 2n5457 to arrive and searching to substitue ceramic caps.
BTW You need 14-pin socket not 16 - a small mistake in Bill of Materials.
Hi adrs!
Nice looking PCB, I hope the project turns out well :D Was it you who left a comment about sourcing the JFETs on the youtube video? I wanted to answer, but somehow youtube does not post the response ??? Anyway, two excellent internet shops in Europe are www.banzaieffects.com and www.musikding.de , they both have most of the parts used in DIY projects.
As for the mods you are proposing:
Quote from: adrs on June 08, 2009, 03:24:26 AM
In fact i would make it like that:
1. standard output
2. overdrive pedal output
3. FX out (before cabinet)
4. FX return (to cabinet simulation) - maybe useless but i want to check this out
you can either:
- use a switch for bypassing the cabinet simulation, as you suggested (use a DPDT, take the signal from the point labeled Harmonics 1-2A on the layout)
- use a signal splitter (taking the signal from the aforementioned point, followed by a simple opamp used as buffer; from the opamp output, you can send one wire to the "FX out", the second to the cabinet simulator).
The option 4 you mention is useless IMHO, since you are alread post-distortion.
BTW, thanks for pointing out the mistake on the BOM :icon_wink:
Thanks.
I'm real newbie to this stuff, so don't worry if i will not be able to run this device i will just start to make something easier and not bother you for eternity :D
I have 50 j201 and 30 2n5457. Do I have to check the Idss now and match them with values on BOM? Or something more?
I'm still not sure about grounding. Do I think right: Ground is conected to the board from input jack socket, which is connected to the metal case, which is connected to the ouput socket.
About the trimmer... I presume that it is some kind of bias thing, but the question is: should i set it in some kind of predetermined position before connecting power or just only play with it afterwards?
Could you tell me if there is something more to do before powering it. Thanks in advance.
:) I gave the JFET characteristics just because I wanted to remember them for future reference (most of the sheets of paper I write important stuff onto get either lost or carelessly thrown away - by me :icon_mrgreen:). There is no need to select them, the distortion may sound different, but not better or worse. I'd say that you test combinations: in some BSIAB builds J201 are replaced by 2N5457 and vice versa.
:) Biasing the 5th FET does not require setting the pot to a specific resistance before powering up, just make sure it works :icon_razz:
:) If I understood correctly your question about wiring, you are right: the input jack has 2 connections (signal and ground to bord), whereas the output has only one (signal) and the ground connection is provided by the metal case (you can see it from this photo http://img27.imageshack.us/i/wiringjack.jpg/ ). Of course the jacks must not be plastic ones :icon_razz:
Great, i got it working...
Is the polarity right in the psu schematics? Bacause i had problems with it - highly possible it is just my fault.
I have noticed that i have a small fuzzy clipping while i hit strings harder...
Is it due to the trimmer which i haven't set yet? Could you tell me how to use it ? ;) Do i need osciloscope?
thanks!
set the trimmer first
is there a pcb for the pots?
Hi rotylee, sorry for answering late ... between exams, no internet and moving I didn't have much time for DIY.
There is no PCB for the pots, I used some veroboard, very good for having a stable wiring base without haing to etch anything.