Thursday 21 February 2013

Fulltone Soul-Bender

Request.  A Tonebender set of transistors should do very nicely in this, aim for somewhere between 50 and 80 for Q1 and Q2, and 100 to 130 for Q3.  This is a positive ground effect and so can't be daisy chained with your negative ground effects, so consider using a small Negative Voltage Inverter daughterboard for your supply to solve the issue.

Info about the original:

Our Soul-Bender is based on the legendary Colorsound and Vox Series III ToneBenders made by Sola-Sound/England in the late '60's that was used by Beck and Page on much of their circa 1968-70 recordings.

Equipped with 3 gain-matched germanium transistor for a FAT, searing lead tone, I also made the Tone control response and range more usable and much less shrill sounding... Full clockwise is SMOOTH sounding.

The Soul-Bender cleans up when you back-off on the guitar's volume control. This pedal has tons of tonal character and even harmonics and of course, true bypass w/ LED is included with every one.







77 comments:

  1. This has nothing to do with this post, but I'd love it if you could post the schematics along with the layouts...so we could play around with values more easily. Thanks! Great site. And this is definitely one a lot of people have been looking for.

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    1. The problem is that a site like this is already construed by some to be on precarious legal standings and whilst that isn't true, and everything myself or Miro post is absolutely legal, that wouldn't be the case with the schematics we created the layout from. They are the intellectual property of the people who created them and unless we have express permission to post we may end up getting legitimate complaints about the site. I want the site to be here permanently and so I will follow the rules to make sure it is. Having said that, there's no problem in posting links to the schematics on the sites they appeared, and in the majority of cases for me, and particularly with more modern stuff, it is freestompboxes. This one though was based on the General Guitar Gadgets Boutique Bender.

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    2. Yeah, I have searched there and found most of the schematics, it would just be nice if they were all here in one place. But, I definitely understand your position. Thanks!

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  2. Well, armed with a Peak DCA-55 (Thanks for the recommendation Mark, you were right it's ace)and a bag full of Germaniums I'm ready to take this bad boy on for my fist full Germanium fuzz build. Wish me luck boys, I'm going in.

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  3. oops... I think that its time to get serious an try a germaniun tonebender... Any advice to source? Smallbear sets maybe?

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    1. Yes a Smallbear or Musikding set would be ideal, depending what part of the world you are.

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  4. I just ordered the transistors from Musikding, they are sorted by HFE value so it's easy

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  5. I´m from Brazil, South America... so i´ve ended up with smallbear OC7x set... I think "Patience" is the word now :)

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  6. oh... and until the trainies arrives, i´ll be trying to build some sort of peltier cooled enclosure just to be safe ;)

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    1. Probably not a bad idea in your climate. Even the simpler option, I'm surprised we haven't seen any germanium builds with small 9V fans in them to circulate the air.

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    2. I think I need a compressor and cooling fins here in Arizona. Just about gave up on Germanium these days.

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    3. Maybe this kind of design is suitable: http://www.penguinslab.com/peltier.htm ...Just with a smaller heatsink and fan... Maybe in a isolated sub-enclosure just for the trainnies (I have an old Nvidea video card waiting to be salvaged!) í´ll post some pics when the frankestain comes alive!

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    4. If you can shrink it down to stompbox size you'll be the new favourite builder of the year on TGP and people will pay a grand for your pedals! :o)

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    5. Haha... it´s a worthy challenge! anyway... i´ve just found something about micro peltier units: http://www.ferrotec.com/index.php?id=module_detail&mod_id=136 ( oops... i´m sharing too much of my industrial secrets here) Let´s cooling that germs!

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    6. Another idea... Somebody have experience with thermsitors? maybe using some kind of thermistors control along with the bias trim could do the job easily... a sort of an... err... "thermal autobiasing" unit.

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    7. Oops again... I found the the Dunlop JD-F2 Fuzz has the thermistor idea implemented already...

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  7. Ok Mark, tag it! I would have had it done a lot earlier except for the fact that it seems I can't tell the difference between 1, 2 and 3 and managed to wire the volume pot in completely the wrong order so the pot was behaving weirdly. Also the tone may need to have lugs 1 and 3 swapping as at the moment it cuts bass when rotated counter-clockwise which doesn't feel right.

    Other than that it is what it is, a souped up tonebender and while I haven't magically turned into Jimmy Page I can get into Black Dog riff territory with it, so I'm calling it a win.

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    1. Awesome cheers mate, I'll swap the Tone lugs and tag it :o)

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    2. I guess it's personal taste with the tone dial, but mainly convention is bass to the left treble to the right, this acts as more of a bass cut rather than a tone sweep though so it kind of makes sense how it is.

      Thanks for another great layout anyway, seeing this was what gave me the final nudge into picking up the DCA-55 on the way back from work :D

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    3. This is really growing on me :D I think I'm going to have a play with a few different transistors to see which hfe sounds best. At the moment I've gone for Q1 and Q2 at around 70 depending on temp and Q3 at 95.

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  8. Ah it appears I may have been hasty in my assessment of the tone control, from the fulltone site:

    "This tone control is unusual. Unlike most tone controls which simply roll off the high end, the SB-2 REDUCES Treble
    frequencies as you rotate the Tone Knob CW while simultaneously INCREASING Low-Mids & Bass! When you turn the Tone knob
    CCW, it dramatically INCREASES treble while simultaneously REDUCING Bass & Low-Mids."

    Looks like you were spot on to begin with, sorry mate.

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    1. Sorry, my bad. Excellent Mutley impersonation by the way.

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    2. Same here :) well I missed the 70's by a month but definitely 80's.

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    3. Thank you IvIark for this one! I need a few passives to complete this and am going to use 2 russian GT108V for Q1 and Q2 and an AC125 for Q3 that I have sitting in my stash. Always wanted an original soulbender and hopefully this will nail it's sound...
      :)

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    4. I'm afraid Mutley references are a bit too contemporary for me :-J I'm a 60s/70s child and so explains why no one commented on the "Dad's Army" reference I made a while back! A bit too colloquial, a bit too vintage,maybe!

      Mark,at first I thought Miro had taught you some rude words in Finnish
      :-D

      Anyway, I can't wait to have a go at this.....Mmm, think I'll get my wife to embroider some "Song Remains The Same" kegs to add to my ever expanding collection of trousers!

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  9. Oh I forgot to mention and ask are these gains ok?
    Hfe for the GT108V 76.6 and 82.8 and the AC125 has 106.1 hfe ?

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    1. Pretty perfect I would say, although slightly more gain for Q3 may be preferable, although then it won't clean up quite as well so it depends what you prefer. Russian transistors are absolutely perfect for Q1 and Q2 in a Tonebender, because they're low leakage and if you bought 50 they would pretty much all fit in the right sort of gain range.

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    2. I used a GT308b for Q1, Q2 and Q3 were MP20As and it sounds great, Q3 was only 95 but it still sounds good and cleans up really well. I've got a bunch of germaniums that I'm going to audition before I box it to see what sounds best. I've never used an original Tonebender but from the Youtube vids I've seen the sounds is almost exactly the same.

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    3. I have another AC125 with hfe of about 120 I can pop into Q3 as well so I will for sure be experimenting to see what I prefer... Thanks!

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  10. 1590A doable.... temptation, temptation.....

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  11. Taking a close look, can't see Volume 2 row.... Is possible that where you point "Volume 3" it should be really "Volume 2"? So Tone 2 to Volume 3, would be right.....

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    1. I just checked my board and it's wired Vol 2 to row 1, Tone 2 to Vol 3. Strange, as I'm sure that was what the layout said when I printed it off.

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    2. You definitely have it right by the way Javi it works fine wired like that.

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    3. Perfect :) Have no choice but buildind it now!

      Thanks, Mad!

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    4. That is sooooo annoying. I noticed that within 10 minutes of posting and corrected it, but somehow I managed to re-upload the older version of the layout! Aarrgghh. Now correct.

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    5. Damm, sounds good!!! Obviously, not high volume right now, but sounds really cool, even with the first GT308s I've tried (60-62-85) Tomorrow I'll try wit 2 GT108V rated 50hfe and a 105hfe GT308 / AC128 125 rated and will bias carefully. By the way, should be biased "by ear" or there's a recommended Q3 collector voltage to try?

      Reminds me a lot of the DAM Grease Box.

      BR

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    6. It is very close to a Grease Box so not surprising you see the similarities. Always bias everything by ear mate, much more important than some arbitrary number.

      I still can't entirely work out the trim pot in this. it's perculiar and seems a unusually large value for what I would have expected in that sort of position. I would probably need to get Mike Fuller's thoughts on it.

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    7. The trim pot doesn't seem to do a right lot in terms of tone but seeing as I used one of the 22 turn ones I probably gave up after 10 turns of getting pretty much the same sound. At that point I as just eager to play with it so I'll have to go back and fiddle some more

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  12. Well,

    Sadly, as I supposed, GT108 pins are unusable with sockets, extremely thin ones, and get loose once inserted.

    I remembered that I have some AC184s with a leakage about 200 and low hfe (40-55), so i used two of them HFE 51 as q1 and hfe 55 as q2, together with a GT308 with 109hfe, and wow, this set does the job perfectly! I think, like in the Grease Box, that a Q3 over 100 is too much. Like the gain that the effect gets, but does not clean well enough with the guitar volume knob, so I think i'll put a ~95hfe one finally.

    Trim is a mistery to me: I've used a multiturn as Madferret, and can't get evident sound changes ... in the whole sweep (about 25 turns), so don't really know why a so large value. Extremely fine tuning? Don't really know, but the effect sounds great anyway.

    I keep on thinking that the key to Tone Benders sounds is Q3, and in Q1 and Q2 you can put wahtever you want, and little if any difference would be noticed, but that's just my opinion.

    BR

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    1. OH, my fault, my fault :P I've used a 1M instead of a 500k :P Well, this trim seems to have many turns, I though that had just finished, but no, it keeps turning.

      From a point (turning CCW) you start to notice an effect on tone and moreover in sustain. After a dozen turns more :P, I've come to a very sweet spot, with eternal sustain, not the slightest oscillation and great tone. If it can be of help, my DMM points 6,7v on Q3 collector.

      BR

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    2. Thanks for the info Javi, I used a 1M 22 turn too so maybe I just need to keep turning, I gave up around 10 full turns.

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    3. Mad, don't know which kind of trim I have, seems to have no end :P I've been taking a closer look, and turning ccw it lowers the q3 collector voltage about half a volt every ~5 turns, so from 9,65 (my PS voltage) to 6,7v it must have been about 30 turns finally, and if I keep on turning ccw, the voltage keeps dropin' so it seems I still have not reached the limit :P

      BR

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  13. Mistery solved :) Did you know that when you wire a positive ground effect as NPN it works fine until a trannie blows? After destroyin' two of my best GT308's (130 and 105hfe ones) now I can tell it for sure :P.

    Yes, don't know what I was thinking yesterday evening, but when boxin the effect wired it as negative ground, and it was working until the Q3 was blown. The only thing I noticed is that the output was quite low The 130 hfe that I installed after, was blown too. Today when i took a single look thought "I'm a bit stupid" Rewired jacks and dc and it works great with a 98hfe on Q3, this evening I'll box it again :)

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  14. Oops :o) Is it very similar with a lower gain Q3?

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  15. Yes, for tone bender like circuits i prefer very low q1 and q2, about 50hfe, and a 90-95 hfe Q3 indeed.

    With a 110-120 you get more gain, but the sound gets more undefined, and does not clean very well with volume knob of the guitar.

    On the Grease Box di put a 95 hfe, and both sound great. I think the Q3 is the key to the benders sound :)

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  16. Well, finally boxed. Definetely, white enclosure, germanium and positive ground are too much temptation for Murphy, but finally is over :)

    Well, one curious thing. Before closing the enclosure, did try a new Q3, gt308, just 80hfe rated, to see the difference, if very noticeable or not. Well, the difference is huge...... the sound of this trannie is just INCREDIBLE after bias, and finally this is the choosen one for Q3. Finally the collector voltage is quite high, 8,4 volts. The AC184 couple for Q1 and Q2 do the job quite well, so I finally did find a destinnation for this bunch of good for no other circuit trannies.

    Guts:

    http://img16.imageshack.us/img16/6895/soulbender.jpg

    Pedal finished:

    http://img16.imageshack.us/img16/58/soulbenderok.jpg

    Hope you like it.

    BR

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    1. Great looking build mate, thanks for the pics.

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    2. You're welcome dude!. One more note that I forgot, I used an AA143 instead of a 1N270. Yeah, the AA143s are worth anny penny. Luckily, I took your advise and purchased a good lot of them!

      BR

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  17. I have a ton of low-gain Si transistors, but I imagine I can't just throw those in here without tweaking some resistors, right?

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  18. Just finished one.
    I didn't use buffer before, as I hated the tone sucking behaviors of some pedal with buffer-bypass. Now I can't go back to the days without the buffer.
    My guitar tone turned from standard definition to high definition.

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  19. ...don't mean to be a dickhole, but I wish, to god, that the exact transistors used, gain gain levels, and bias setting where explicitly caled out on fuzz layout! :(

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    1. I can't speak on behalf of Miro or anyone else contributing to the blog, but I'm not here to give you personally everything you seem to expect and that isn't what this site is about. If you want the exact pedal then buy one. If you want to research a bit yourself rather than expecting someone else to do it for you then join FSB and read the thread which will contain all the information you demand. And whether you intended to come over as a dick or not, considering the limited time I have to devote to this because of my family and my real job which pays my mortgage, that's precisely how you come across. If it's not good enough for you then please get your layouts from somewhere else. I'll refund the £0 that you paid for everything here as soon as you leave.

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    2. Sad to say, but i second Mark's every word. Lots of people seem to want a lot more than can be offered.
      +m

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    3. Very bad of you, Mark and Miro.

      You should send us a soldered and wired kit, including a drilled and painted enclosure. Of course free of charge.

      This way we are able to verify the layouts.

      BR.

      PS. Please, just NOS and mojo components.

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    4. Javi: :D

      That is true that we're getting more and more demands about how we should do things and what we should do. I've drafted a FAQ concerning other things too, but that'll need some polishing before we publish it.

      A few main problems today include: Even experienced builders make mistakes too, but many still rather let us do the debugging for them. It's too often that builder comments on a post "mine isn't working" before checking their own work. Granted, there are some errors in our layouts from time to time, but people should still be able to think for a second before asking for help. The continuous demands are very exhausting and affect everything we do.

      I'm going to say this just once. If you don't like something we're doing, please *do not* let us know. There are ways to bypass this - look for layouts somewhere else, draw your own or just buy the box you need. If you can find some other layout site that has helpful and friendly comment section with reasonable respond times, go there. Also, nothing is stopping you from building your own site and doing all these thing exactly as you want to. We have our way of doing things and we just love to do it like we do. Main reason why i got in to contributing to this site in the first place was the friendliness of conduct on comments and whole user community. The page is getting bigger and bigger, so there are more and more people coming in - which means more debugging through comments and more requests and demands. Everyone should remember that we're not getting paid for doing this and we have familes and jobs to take care of. All the information (and more) we use for our drawings can be found from the internet. You should be able to find it too.

      I guess that's all i'm going to vent on this subject.

      People. Please behave. And let's keep this site as it was, and is. A friendly, nice place for everyone reading it and contributing to it. It's not that hard. Just have a cup of coffee, cigarette, tea or what ever daily substance you like - before doing/saying/commenting anything. That ten seconds usually makes a difference for me.
      +m

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    5. Ditto on Mark and Miro...

      This is a nice and friendly place where we come to take a breather after a long day of taking crap from the world.

      There should indeed be a prominently displayed faq containing a few well chosen words for whiners, freeloaders and just general PITA types.

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    6. Goran: So you're demanding a FAQ!
      :DDDDDDDDDDDDDd
      +m

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    7. I'm glad you picked up on that! :)

      I rather enjoy my sarcasm.... lol

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    8. I do read this language called sarcasm pretty well :)
      +m

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  20. Too true! You guys have an amazing site and I've noticed most people on here like to help each other on there various building quests. I love the challenge of finding the schematics, using it to trace the layout so as to learn how dmd what's going one with the effect and there's nothing better than if you do have a fault than to figure it out yourself and if its going to help others, passing on the info.
    Well done maties and thanks to mark and miro especially for giving up some of there time to keep us all chugging along. Cheers!
    Ps: if you don't know something, the net has a search facility so I'm told....... :)

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    1. Thanks guys. We obviously want to make things as easy as possible but we aren't in competition with FSB where the real circuit analysis goes on. If myself or Miro don't mention a particular type of transistor or a gain range it's because we either don't know, or maybe because we think specifying it would be counter productive (I'd prefer to build anything with a good Russian or Japanese germanium transistor rather than a leaky NOS Newmarket piece of expensive crap which is a 50/50 gamble as to whether it will even work). And of course gain range is also completely a matter of taste depending on your gear (single coil / humbuckers for instance), personal preference etc. So sometimes you have no choice than to do a bit of leg work yourself or simply choose your own transistor preferences. Or hopefully look through the comments and see what worked well for other people.

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    2. Warm feeling when there's lot of people appreciating what we do. Not like i was going to stop anytime soon anyway :D
      +m

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    3. What I don't understand, if a person was to read through the post, they would find all the information they were asking for in the first place?

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  21. I got mine completed today and it sounds great. I first tried a tonebender set from smallbear (NOS black glass Mullard OC75's) and it sounded very good. then I tried two Russian IT308B's for Q1&Q2 with hfe of 55 each, and a NOS Tungsram AC128 for Q3 with an hfe of 92 and I think that it sounds even a little better. IMO, this is a very nice FUZZ!!!

    pics below:

    http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/SoulBender/S-Bender-01.jpg

    http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/SoulBender/S-Bender-02.jpg

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  22. Nice build, John. Clean and tidy.

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  24. Hi Ivlark,
    I build a OCD with succes. A great sounding pedal. Now I want to build a first class Fuzz pedal.
    On the vero the trimmer (trimpot is rectangle), but i can only find a triangle trimpot (as show on this dutch site http://www.newtone-online.nl/catalog/product_info.php?products_id=1475).
    Can I use the triangle trimpot. If so, how is it positioned on to the vero?

    Thanks.
    Jan

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    1. Yes you can use them but they won't fit in the holes shown. You can make a little daughterboard though like at the bottom of this page:
      http://tagboardeffects.blogspot.co.uk/2012/02/offboard-wiring.html
      and then just take the wires to the holes used in the layout. You could even use solid core wire so you can mount it directly over the position the trimmer is shown on the board.

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    2. Or of course you could just make the whole board a few columns wider so you can accommodate that trimmer

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  25. Hi guys,

    do you think a vishay 470k trimpot will be fine in biasing Q3?

    thanks

    Gian

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  26. I built this a while back and just came across a germanium set i had forgotten about. It works and sounds great but the volume knob is super sensitive at the beginning of the rotation. it goes from silent to super loud immediately. Anyone else have this problem? I dont think its the pot as I put it on my meter and watched it as I went through the rotation- looked pretty typical.

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