Tuesday, 26 June 2012

Fairfield Circuitry - The Barbershop

Guillaume Fairfield is another one of the good guys who has been very helpful and open about his circuits during discussions on the forums.  If you like the effects then consider supporting the builder and buying something from him in the future.  If you want to try one before you buy then this may be a good starting point.  This layout omits the mosfet used for polarity protection and just uses a Schottky diode instead.

Info from Guillaume about the original:

Have you ever sat in a barber's chair wishing your tone was as slick as your freshly shaved upper lip? With the Barbershop Overdrive on your pedalboard, you could keep your moustache and sound good doing it.

The Barbershop is an original design, not a clone.

Raw, gritty, warm, smooth, open and transparent are all terms that have been used to describe this overdrive. It sounds great with any setup, but truly shines when used to dirty up a tube amp.





Here's demo of Geiri's build. 2N3904 in place of 2N2222:









91 comments:

  1. Are there any substitutes for 2N222?

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    1. They have a similar sort of gain range as the 2N3904

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  2. Awesome, thanks! Trying this one later tonight.

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  3. I don't have a 1N5817 but I have a 1N5819, would that work?

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    1. Yes no problem, it's the same thing rated at a higher voltage.

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  4. Thanks man! I'll verify this soon ;)

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  5. Hmm the drive and sag knobs are working but the volume isn't doing anything at all. There's no effect when the sag knob is turned all the way down though. I'm getting a sweet drive tone from it so the circuit is working. Any idea?

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    1. No sorry about that, I'm talking about the drive knob isn't working. The volume and sag work fine. No volume with the sag all the way down though (not sure if that's normal). The drive knob has no effect whatsoever.

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    2. Well the sag pot starves the supply so it is acting as I would expect it to. Drive pot problem seems perculiar though:

      Drain of Q1 > 47n > 33K > Drive 3
      Drive 2 > Q2 gate
      Drive 1 > 4K7 to ground

      Exactly as per the schematic. So the Drive pot will put more resistance between Q1 and Q2, taking the gate of Q2 to ground with only a 4K7 stopping it from being totally grounded and so preventing the Drive pot from silencing the circuit. That seems like a pretty standard arrangement to me used on a number of effects like the Big Muff, and the layout looks correct to the scheme to me. Very strange.

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    3. Sorry man! I messed up the 1K resistor going from Q2 to ground. It works perfectly and sounds AWESOME! Verified ;)

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    4. Brilliant, top man! Thanks for that

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  6. One thing to note is that the 2 drain resistors, in this case the 8k2 and 9k1, are closely related with the jfets characteristics. You can really tweak the character of the distortion by playing around with these values or even with different transistors. To really have some fun, you stick a 25k trim pot on the drain and a transistor socket to swap out some jfets.

    Happy to see some people having fun with this.

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    1. whoops... last post was by yours truly.

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    2. As usual, thanks for being so helpful about your circuits Guillaume.

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    3. I've got to say Fairfield, I've built a lot of what Mark posts here and some are great, some not so great (as in the designs, not the layouts) but this one is definitely one of my all time favourites! I tried to get as close to the values as possible. I didn't have 8.2k and 9.1k but I got them to be 8.4k and 9.4k (by having two resistors in series) and it sounds really good! With my Strat into a JCM800 = perfect! I don't know if it's the transistors but so far I've always been very happy with anything that uses J201!

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    4. I checked out the Fairfield website and can I just say if I could afford it, I would buy all of your products strictly on how honest and right to the point you are about your products. And the fact that everythings sounds so damn cool is also a plus :). It's refreshing to find a company that is doing their own thing. Look forward to a new customer in the future. The four eyes is calling my name!

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  7. Made this last night also, fantastic pedal... REALLY like this one ;o)

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  8. I just realised that I accidentally put a 470u instead of the 220u. Could you tell me what difference it makes?

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    1. Bigger caps will smooth more ripple and potentially remove more noise. If you are getting a lot of noise then it's worth experimenting but the power supply will often have it's own filter caps and so the differences may be minimal. I tend to stick to 47u to 100u if I was doing something for myself and not worry about it too much, mainly because I have a lot of them that are quite compact and when you're getting up to 220u or 470u they can get quite physically large. Also bear in mind that a big filter cap can sometimes remove oscillation that you may want in some fuzz circuits and tame things down too much, as we have discovered with a few builds on this blog. So sometimes less is more.

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  9. Alright, thanks for that info! I've been experimenting a little with the power filters but nothing dramatic has happened so far. I though I was using a 220uf cap when I put the 470uf but to me, the pedal sounds very good like this! I don't know if it's actually changing the tone much.

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  10. Words can't describe how excited I am to build this.

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  11. would I be able to use a BAT 41 instead of the 5817? Or should I just order some of them, just don't have any schotkys on hand besides the BAT 41s

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    1. Yes mate, I only opted for a Schottky because they have a lower voltage drop than more usual alternatives such as the 1N4001. But the BAT41 will do the same thing, or even omit it entirely if you're not bothered about reverse polarity protection.

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    2. How is it used in the circuit. Will it affect tone?

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    3. It's just used in case someone plugs a wrong polarity supply in, the diode will block the current and so protect the components. The original used a mosfet for reverse polarity protection and so if anything, omitting it entirely will be more true to the original because you won't get the 0.4V(ish) voltage drop as you will from the series Schottky. Using a mosfet gives you something like a 0.1V drop.

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  12. Just finished this today. Pretty low gain ( which I think it is supposed to be ) but I don't seem to be getting the gain that is in the clip. Are the J201s supposed to be around 4.5 - 5 volts on the drain? It sounds pretty good but with drive maxed out, I get just a touch of dirt.

    Not trying to criticize the circuit - just want to make sure I've done it right.

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  13. errr...whoops. Just took a listen to the clip again and realized he's using a Les Paul. I was testing with my Strat. Pulled out my Hamer with 'buckers and it sounds just like the clips. Think this might just turn out to be a very good stacking pedal like the DLS.

    Thanks

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  14. Can a pedal add something, yet be transparent, all at the same time? I keep playing this through different guitars and different amps and it adds something to each combination, yet it doesn't subtract from them; the basics are left intact but a richness is layered in. This is one of the best things I've built here....keeper

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  15. question for you mark. i built this one, but i'm getting around 6.4 volts on the drain of the J201's. i thought i remembered reading that Jfets should read 2/3 voltage at drain. it sounds pretty good, but after reading some earlier posts, i wonder if its right. what voltage should i be getting at the drain of the J201's? i subbed some 2.2M resistors for the 2M, and i subbed a 10K for the 9K1. could these substitutions be an issue, or are my voltages good?

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    1. Well Guillaume mentioned above that the 8K2 and 9K1 were quite important for the J201's characteristics, and he'll have played with this circuit more than anyone else so I'd trust him! :o) The problem with using fixed resistors is that you then may have to swap fets to get ones within the recommended voltage range (I'm sure it's between 5V and 5.5V that is usually recommended). For Fairfield the fixed resistors may make more sense because it avoids having their pedals returned under warranty because someone has been playing with trimmers. But for the DIY builder a trimmer seems like a more attractive proposition to me, then you can vary the voltage to suit the fet rather than swapping the fet to suit the voltage.

      So personally I'd probably use trimmers in this, then you can experiment and get a good idea what the differences are at higher and lower than recommended voltages. You may prefer slightly higher voltages and so if it sounds great already, you may prefer not to "fix" it.

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  16. i definitely mucked up my sag pot somehow, just got back from vacation so ill check it out this week. when the pot is anywhere between full on and full off it acts like the voltage is starved (%50 on the pot acts similar to what it should sound like with the pot around 0) but other than that it really is a great overdrive. So great that 1. i cant settle on just one setting and 2. its kicking a pedal off the board.

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  17. Idk. Havent had a chance to open er back up yet. I could have just messed up the wiring. I kind of rushed it a bit before I left for vacation. Had to get it done lol. Other than that though it is a seriously great sounding pedal. I especially like it as a clean boost. Might use it as one because my pignose g40 doesn't get along with my Klon.

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  18. Idk. Havent had a chance to open er back up yet. I could have just messed up the wiring. I kind of rushed it a bit before I left for vacation. Had to get it done lol. Other than that though it is a seriously great sounding pedal. I especially like it as a clean boost. Might use it as one because my pignose g40 doesn't get along with my Klon.

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  19. I built this last night and it is sooooo great. Thanks Guillaume and Mark! I love this circuit!

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  20. Built this guy, but I'm having real trouble with the sag control - it only works for about half the sweep, then silent.

    My voltages are

    q1 - D 5.78 S 0.73 G 0
    q2 - D 6.37 S 0.51 G 0
    q3 - C 9.3 B6.37 E 5.81

    Any ideas? Do those bias voltages look okay?

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  21. i built this one a few weeks ago and IMO, it's one of the best sounding pedals that i've ever owned. thanks Mark!

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  22. I did this as a first time project and everything went well except I seem to have a wired oscillation effect when I turn the knobs all the way up. I watched the video for the true Barbershop and I can not replicate the same sound. Any help would be appreciated. On a side note... when I was breadbording this I was picking up a AM radio show.. it was crazy.

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  23. I'm having trouble with my sag knob. I assumed the wire that says "sag 2&3" should be connected to both the 2 and 3 lugs of the pot so I wired it to the second lug and then wired that lug to the third lug. The drive and volume knobs respond as expected but I don't get any discernible effect from the sag knob.
    Did I do something wrong?

    Also, thanks so much for the very great site. I plan to use it a lot in the coming months!

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  24. I'm getting the same effect with the SAG knob as the others.. It only works 50% of the rotation?.. different value pot maybe?

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    1. The problem is that there will come a point where the circuit is starved and then you're not going to get anything out of it. You could experiment with a lower value pot, or maybe even a reverse log to minimize the useless part of the rotation.

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    2. Fixed... A B5k pot works perfectly against the demo... also, it needs flipping as currently it works in reverse to the demo.

      Definitely recommend the B5k... it cuts off right at the end of the rotation now ;o)

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  25. How would one go about replacing the 8.2k and 9.1k resistors with trimpots? Put legs 1 and 2 of the trim where the legs of the resistors would go? What would I do with leg 3?

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    1. Just leave it hanging, value across legs 1 and 3 is the full value of the pot and you are interested in either 1-2 or 2-3.

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  26. Also, I was thinking it could be cool to add an "always on" boost before this to have more gain if wanted. Kind of like the Skreddy Lunar Module and Screwdriver have.

    Do you think the Catalinbread Sagrado Poblano Picoso would play nicely with the Barbershop?

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    1. Can't comment on your specific question but I was considering pairing it with a RC Booster in one 1590bb once I build this.

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  27. Hello Mark, Miro and others! :)

    I just finished building this and apart from it being incredibly noisy when I get physically close to it (should be fine once I box it), it works.

    Now, as to the "proper" operation, I have a question. I've replaced 8k2 and 9k1 with 20k trimpots. On one endpoint of sag pot, jfets are starved and I get virtually no sound. This is to be expected. Where I'm drawing a blank is the other endpoint of the sag pot. Depending on the value of drain trimpots, I can get the drain voltage to be as high as 9+V. What's the value I should be aiming for (the maximum drain voltage)? How high is too high? How high is useless? :)
    Obviously, on one hand it could be a matter of sound preference but I'd hate to have j201s fry once boxed, it'd be a pain to swap them...

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  28. Just built this today and I don't want to get to excited but.....this is exactly what I've been after and I didn't even know it. I love this pedal. I used Vince's advice and used a B5k pot for the sag which works great. Thanks Vince for that. No cut out at all and completely useable throughout the whole sweep. My strat and fender amp sound great with link. Thanks do much for this layout and thank you mr Fairfield. Awesome!!

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    1. What's your bias voltage on the FETs?

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  29. Hi Goran, with the sag off q1 was 6.2v & q2 was 5.8v. I matched the gets using the jfet matcher on this site ( approx 1.1v to 0.1v) and the 2n2222 has a hfe of 189.
    I used trimmers but just used them to adjust the resistance precisely to the listed resistances. I believe the trick is to have the jfets a closely matched so the drain resistors can give you the correct voltage ratio on the drains.
    But I could be wrong.......hope this helps mate.

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    1. Thanks for that, Jeff!

      I'm not all that familiar with the intricacies of fet matching and which matched parameter does what for the circuit, so I biased them both to 6V drain voltage (2/3 Vcc) as per Fairfield's own admission someplace on the interwebz. I was just wondering whether "better" (whatever that means :) ) sound can be obtained by tweaking the "sag off" bias values without going too much overboard and frying the fets (dunno how much voltage/current that takes, either).

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  30. I have built this and it works but not very well. I biased the J201’s to 6 volts with 20K trimmers and then tweaked them for maximum output. I used a 2N2222 for Q3.
    Whilst it clearly works in the way that others have described it I am unimpressed with the “Sag” which is more like a “Gag” and the amount of drive I got was very low with a single coil and just usable with a humbucker. I suspect, that having heard the demos and read the other comments, that my J201’s are particularly poor performers. I also tried 2N5457’s but the gain and volume was even lower. If the quality of the distortion was as good as say, Geiri’s Azabache I could live with the low drive but it isn’t and the “Sag” is nothing like as impressive as that from the Mictester Secret Sauce. Whilst I’m sure that Guillaume’s production models are much better I don’t think I can be bothered with this J201 selection and biasing lark any more and if others feel the same way the best bet may well be to actually buy one from Guillaume!

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    1. I've built two of them now and both of them are AWESOME pedals. neither one has the issues that you described and they are in my top 5 list of great OD pedals (and i have more than 150 of them) I didn't use trmimmers for the J201's, just built it exactly according Mark's layout

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  31. John K wasn't kidding. This is the best bass overdrive I have ever used, full stop.

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    1. I'm still floored every time I hit this thing. My Gallien-Krueger stack roars like a cranked SVT, but still responds with the solid state punch that I love. This is exactly what I've been looking for, the sound of my bass, just with a bit "more".

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  32. I made the Barber Shop last night and agree : really excellent pedal.
    The only difference that seems to have with the original is with the Sag control : Guillaume write in the specification sheet that "The Sag control reduces the voltage to the amplifiers as you turn it counter clockwise" and " Full voltage is applied when the control is set fully clockwise. It is at this setting that the pedal has the potential to be its cleanest and loudest."
    On my clone, the voltage reduces clockwise and is the cleanest and loudest counter clockwise.
    What about you ?

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    1. since it's a linear pot, just reverse lugs 1 & 3 one the sag control and it'll work in the same direction as the original. I left mine as is since, to me, it made sense to have more sag turning it clockwise.

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  33. Two Days Two Drives:-) Both awesome on their own and really good for stacking: http://www.inkshed.dk/2014/04/11/diy-stomps-two-days-two-drives/

    Thanks!

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  34. Was just finishing the board for this when I realized that my 220u caps are only rated at 10v. I put a 100u 50v cap in instead. Is this likely to be an issue?

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    1. No that will be fine, 100u is enough as well IMO so I'd just leave it at that

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    2. mmm...you could solder 2 100u caps in parallel...it would be closer

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    3. Thanks Mark!

      I thought about 2 100u caps in parallel, but couldn't find a way to really fit them on the board.

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  35. Just finished building this except for boxing it up and this pedal is just awesome! I used 15K pots for the drain resistors and the specified A10K for the sag pot. I get pretty close to full range from the sag control before I start to lose signal and that last bit is a really gnarly fuzz, so I left the A10K instead of using a C5K.

    Great pedal Guillaume, and I love that you have been so open with the design and sharing your knowledge!

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    1. Yes Guillaume is definitely one of the good guys

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  36. Just finished this and it sounds pretty awesome! I would definitly have some extra J201 on hand to fine tune the sound. I had 20 and there was a big difference in the amount of distortion when switching between them. Cheers!

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  37. Finally built this, sounds good, but I like my Fetto and Marvel Drive better for the OD tones....however, as a clean boost, it adds an incredible fatness and presence that is great on both clean and OD channels. It's my new "always on" pedal.

    http://img.photobucket.com/albums/v325/jallenshaw/imagejpg1_zps25fbb89a.jpg

    http://img.photobucket.com/albums/v325/jallenshaw/imagejpg2_zps32b57b55.jpg

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  38. I built this pedal a couple of months ago and I use it exclusively for bass, I would like to add some type of tone pot to it just to reduce the treble presence a bit. I was just thinking of adding a passive tone pot with a .022 cap coming directly from the output of the board. I don't need to tweak any other part of the eq other than cutting some treble when I need to. What value tone pot would work for this?

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    1. There's a passive BMP tone control with lbp booster after it to regain the lost output. I would just run the output from the barabershop to a daughter board with the tone control, and then the new output is from the tone control.

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    2. thanks for the response. I thought about that option but I wasn't sure that I want to change the entire eq response. Even if I adjust the tone stack to have flat mids when centered with BMP tone control. If I roll back on the highs I start to boost the lows. I'm looking for just a straight high cut. That's why I thought a passive tone control that would just roll highs might work.

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    3. You could add a the SWTC, but remember. When you add a passive tone control you will loose output. The only issue is that you don't know how much output until you try it. If you are going to try it I would breadboard it and see how it affects the output level. If you're ok with the amount you loose go with it, if not use the BMP tone control. I personally use the BMP tone control with the gain recovery from the booster, as I can control the final output from the trimmer on the booster section, so it's just a little more controllable IMHO. Both are great options though.

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  39. Yeah that will be what you want. This pedal has plenty of output so no need to worry about adding another gain stage really.

    Check this out
    http://www.muzique.com/lab/swtc.htm

    You can solder the components straight to the pot to avoid an additional daughter board

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  40. Fairfield Circuitry recently released and update to this pedal - the Millennium Edition. Would love to see an updated vero layout as well as I am planning to build a second one.

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  41. I thought about just adding a 3 position switch like they have with the center being full signal and the left and right being different amounts of high cut. I just want to have that type of option with a pot. Can I just go with a 25k pot or does it have to be a higher value?

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  42. The description suggests there is some refinements to the rest of the circuit as well. Not just the high cut. Maybe not though. Would like to know before I build my second one.

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    1. It's all going to be guess work until someone looks inside one. So if you're desperate to build one to the same philosophy you can make your own refinements based on the suggestions, otherwise it's a case of waiting until someone traces the new one to see precisely what her has altered in it.

      I try to treat every builder equally and not to have favourites, but personally I'm in no immediate rush for that to happen. Guillerme is one of the good guys who has been very open and helpful in the past about his effects, and for once it isn't someone who is just rehashing the Tubescreamer like so many others do. So because of that I'm happy for it to remain unknown for a while. I'm not eager to see a JHS, this1smyne, or anyone elses "V1 to Millennium Edition Mod" based on information they took from the DIY community for nothing and used for their profit. I'd prefer to see him sell some pedals for a while first.

      It won't stay secret forever though.

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  43. Hi - I've just built a second Barbershop and it works and sounds great. But I get a loud pop when I switch the effect on. I guess I need to put In a "pulldown resistor", but I have a little trouble working out where it should go and which resistor value I need. Can anyone help me out?

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    1. There is a 2M pulldown resistor from the input to ground and the volume pot has the output covered. So your problem must be something else.
      +m

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    2. Hmmm... I've been running the pedal on my board for a week now and the popping only occurs intermittently. I guess it might be a bad solderjoint somewhere, but strangely I had the same problem with my first Barbershop. So I guess whatever it is I have repeated it.

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  44. Hello,

    Is there any bass mod for this circuit ? I read that many people used this pedal on bass guitar. So I would like to know if I need to change some component or just "plug and play"..

    Thnak you

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    1. built it for my bass, sound freaking amazing stock. no need to change a thing. btw, net to the bjfe blueberry this is #2 on my list of favorite OD's for bass.

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  45. I need some help with this one, I have build one before that worked perfectly. Now I'm trying to build a second one. I have tried 5 times already. All the times from scratch. Everytime I had the same problems:

    1 - The SAG knob is not working properly. When the pot is all way up the pedal sounds as it should, but as you mess with the sag pot it starves too much, to the point it gets fully silent. I put a 1.5k resistor between lugs 1 and 3, and then it seems to work as its supposed.

    2- When the pedal is off, i get a really high pitch noise. The noise changes as you mess with the pots. If I unplug the power the noise stops. And the noise is not very loud when both cables are pluged in the jacks. But if I unplug the input cable, the noise gets super loud!

    At first I thought I had a problem with my j201's. Cause of the SAG knob. so I bought it from 3 different sources, tayda, ebay and mammoth. all do the same thing. replaced the 2n2222 for the 2n3904...no luck as well. I believe both problems are related to the power.

    Any ideas?

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  47. I built this circuit today and it sounds great! Is there any way to cut the bass just a a tiny bit?

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  48. Has anyone looked inside one of the newer models - with the tone switch - to get an updated layout? Really interested in building one.

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  49. Hey, i have built this and have a weird and annoying problem:

    At full volume, The circuit passes the clean signal, not boosted, same level as bypassed. Below that, it gets very quiet soon. When i use the Drive knob, it seemingly passes signal at both ends, in the middle there is nothing. Sag does change the Voltage on the Transistors, which seemed correct to me (6.x-ish on the JFET's drains when not starved).
    I triple checked all the connections and separated the soldered traces with a knife.

    Any clues? Thanks for any idea.

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    1. Even though you checked it, it's more likely you have a bad connection or stray figment of solder somewhere...

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  50. Did you get this sorted? I assumed that in order to go to two lugs that you should have two separate wires, not linking the two. Have been trying to make an ampeg scrambler and the fuzz is really weak - if Ive misunderstood then this is the most optimistic I've been about getting it fixed!

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