Saturday, 15 December 2012

Brown Sound in a Box II

Description from the General Guitar Gadgets site:

Brown Sound In A Box version 2 (BSIAB2) is an excellent distortion pedal designed by Ed Guidry. Based on the AMZ MiniBooster cascading work done by Jack Orman and further refined by Aron Nelson and Doug Hammond.

This is one of the best heavy Marshall-type distortion boxes that we've heard and it also performs very well on low drive settings.







Modded version with Contour pot



Geiri's demo of his build:


31 comments:

  1. Yay. And I requested this less than 24 hours ago.

    You sir are beastly

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  2. Contour knob mod . . where would you add that ?

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    Replies
    1. I'll add a modded version of the layout

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    2. wow that was fast, thanks :)

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  3. The contour knob isn't doing anything for me, but I don't mind because the rest is working fine!

    How can I change the mids? I feel that my build is just a little bit mid-scooped.

    I built another 3 knob version and the volume & gain is quite low. I reckon I might have mixed up a resistor somewhere? What could cause both the volume and gain to drop?

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  4. First of all, thank you for this layout! Just built it, sounds great but...I have three questions:

    1 Where I can find the schematic you made up this layout from?
    2 The circuit goes really soon in feedback and it's quite noisy...not boxed yet btw...it's due to this?
    3 How can I set the bias properly? How many volts and where to put the multimeter...I know I'm not a pro! It may sound stupid but, my trimmer does not have a turning end...it like a perpetual wheel!

    I' ve built the hao rust driver (nice one!) and the sho superheated too which sounds amazin but it's too strong! Even with the knob on 0 and the superheated not activated, it gives at least 3-6db of vole gain! Can I tame it a little bit? :D

    Thank you again and sorry for my english!

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  5. Ok ok...bias done! There were something wrong about the battery... bias at 4.5v.
    The bsiab sounds nice but there is a ton of hum as the volume and gain are increased.

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  6. To bias this one according to GGG, you must put the drain voltage of Q5 at 3.4v then you can adjust to taste if needed. Higher the voltage, the more noise you'll get.

    My question is this: I noticed that GGG wires the contour differently than the way you have yours. Will this cause an issue?

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    Replies
    1. GGG is wiring only lugs 1 and 2, where yours wires lug 3 were lug 2 of GGG wires. I did wire this one up and I also wired up a GGG version and got similar end results. I can see this question I asked earlier is not a big issue. I was just concern if there could be future problems..... It works and sounds great except for that whine sound in the background. I think it might need shielded cable.

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  7. No way to get a nice sound from this effect...the last batches of 5457 and J201 that I've purchased are pure (and expensive) crap.

    Absolutley imposible to get a Q3 whose Source biases at 0,9 -1v, (0,45 maximum) so the effect sounds like pure shit.

    I'm afraid that jfet builds are over, no way to spend 35 euros fot 100 pieces and barely get 2 or 3 working ones :(

    BR

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    1. Wow, not a very good return! I wish we'd been given a lot more notice about the JFETs so we could have stocked up. A year or so ago you could have got 1000 Fairchild's for about £60 and we'd have been ok for ages. I did manage to get about 250 of the J201 and 2N5457's but I would definitely have got lots more if I'd known.

      The only thing left I suppose is swapping good sets around more than one pedal, so everyone should make sure they use sockets and I probably won't even cut down the legs now :o)

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    2. Well, finally I was lucky :) The J201's are crap, but I had still a bunch of 2N5457 from Conectrol, so built Chad's version (Cmatmods Brownie): Q1= MPF102, Q2 to Q5: 2N5457 and sounds really great!

      Nice high gain Marshall in a Box, really hard distortion, love it! (and the Brownie is supposed to be milder than the original!)

      BR

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    3. Wow... This might be the reason why my simple Mu-amp doesn't work. Bought my J201s from tayda, but I can't seem to get the Mu-amp biased right, I barely get unity gain :(

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    4. J201s from Tayda, are out of spec units from many months ago, just like 1N34 diodes and some other components.

      BR

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  8. Hmmm... One of my suppliers mentioned earlier this year about bogus 2n5457's coming out of China. I didn't know that it affected J201's as well, but I suppose that it makes sense - it's a very similar product.
    Does anyone know for sure where tayda etc. are sourcing their supplies?

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    Replies
    1. Trough hole fets are no longer in production, so you have to stick to residual stock :(

      Once finished in USA / Western europe we just have the China stock, and it seems that these remaining fets are the ones that were once rejected for being slightly (or highly) out of specs.

      So now to get J201 is really expensive, and i seems that you'll get crap if you purchase it from Chna, or insanely expensive (about 3 bucks / piece) if you get the very few reaming stock in Europe / USA.

      BR

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    2. Hm... Might be a stupid question and shows my lack of knowledge, but maybe the jfet designs could be reworked for mosfets...? BS170 is pretty much available everywhere. As much as I know the jfet designs were to emulate tubes (at least in the guitar effects field of electronics) and I remember to have seen a few articles about emulating tubes with mosfets. Or mybe I'm just talking crap... But the Zvex Box of Rock would be a good example I think.

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  9. Just built this one and my god what a great sounding pedal!!!

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  10. I'm just seeing this was done as a vero board. I'm gonna have to try this. Etched a PCB and built one of these up a few years back and it sounds killer (just getting back to playing it now)!! However, mine is noisy as all heck. I noted in the GGG file that there is a diode that drops the B+ line voltage by 1V, so normally you'd do half the voltage in and if 9V, 4.5, but since 1V drop, you'd bias Q5 at 3.5V...or in this case, they suggest 3.4V. I did this. It didn't cure my noise issue which seems to be RF noise. So, like I said, I'll build up this verified vero board. I don't see the diode on this layout thou!! Does that mean we bias at the standard 4.5V then??

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  11. This sound so shreddy whohohoho, very nice! A little bit noisy, but nice sound! Here is a video :)
    https://www.youtube.com/watch?v=ChK2BMyA7Xs&feature=youtu.be

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  13. Hi guys. Unfortunately I forgot to order the 470p capacitor . However I have the following capacitors:
    50x1μF
    50x 100 nf
    50x 100 pf
    25x 10 nf
    25x 2.2 pf.

    Can 5 capacitors 100p in parallel work well?
    Do you have any idea?
    Thank you

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    Replies
    1. 5x100p caps in parallel will equate to 500p which is close enough, but may add noise. If you had 2x1nf caps you could run them in series to get 500p..?

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    2. yes they will work. but it will be hard to solder all of them on that board. even if you pre-solder them offboard and then put this thing on, it will look really messy. is it hard to buy some 470pf?or you don't have any electronics store near by?

      i would wait to get a 470pf....soldering 2 components to get the value you want is ok, but 5 is too much for me!

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    4. Unfortunately I don't have any electronics store near by . I will have to order it online.

      Thank you for the replies.

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  14. Hellow good morning
    My name is jose
    I am of spain
    I not undestand the note "level 2 to output"
    Where are level 2 ?not can see this in scheme.?
    I have this in constructión
    The sound is great
    Thanks sorry my bad english
    S.O.S help please

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  15. "level 2" is the lug 2 of the level pot (center)

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  16. I just finished a plexidrive and it was a pain in the @$$. Doesn't this need trimpots as well? Why is there only one? No biasing needed???

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    1. Q1 & Q2, and Q3 & Q4 are muamp pairs which shouldn't need biasing. Q5 is a single gain stage which is why it has a trimmer for biasing.
      So as long as you get good JFETs you should be ok with Q1 to Q4

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