This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Wednesday, September 16, 2015

BearFoot FX Pale Green Compressor

Here's another great circuit by Bjorn (who also designs all the Mad Professor stuff). It's an optical compressor that's very similar to the Mad Professor Forrest Green Compressor. It's not too heavy handed, and is, as Bjorn has said, "The compressor for people who hate compressors."



15 comments:

  1. Hello! I found some errors, the diodes 1 and 2 are reversed, the resistance of 47K leaving the base of Q1 to ground is 22k in the schematic that I found online. The capacitor 47U not found in any schematic. Check and everything seems fine, but I still do not work, then I will review in detail. I hope you understand, using a translator, sorry !. Cheers

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    1. Thanks for catching that. The layout has been corrected.

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  2. Is this a V1 V2 or V3 version of pale green?

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    1. Whatever version this schematic is based on:

      http://johnkvintageguitars.homestead.com/Effects/Compressors/BJFE/PaleGreenschematic.png

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    2. I saw 4 versions of this pedal, each one representing different compression character. I heard it has 3 or 4 versions each one representing a different amount of compression. I have no idea which version is that schematic but it has year 2013 on it so I guess it must be V1. I watched a few demo videos and V2 seems to be the most interesting one.

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  3. Is there a way to substitute vactrol unit without tinkering? NSL-32SR3?

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    1. I would think so. Just compare datasheets. Google is your friend.

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  4. Hi!

    Pls mark it verified.

    Superb compressor. I suggest to put a1m instead of a500k for comp pot and replace w20k dual gang with a20k or a25k single gang pot -> tone b1 to lug 1, tone b2 and a2 to lug 2 and tone a1 to lug 3.

    215R must also be adjusted depending on the led/optocoupler model. Use 1k or 2k multiturn trimpot and your ears for optimal compression.

    Cheers.

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    1. Thanks for verifying and for the report!

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    2. Would I serve a ldr 500k in the dark 5-10k in the light? I have no way to get the vtlc6?

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  5. What if i split the dual gang 20k pot to 2 pieces of 20k pots ?
    Does the sound going to be weird if i turn both of em with different angle ?

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  6. hello my functional pedal but it has a slight distortion as an overdrive I used: Tl071, BC549Cs, LDR 1M dark and red led 5mm
    should the problem be the LDR? Would I use 500k dark instead of 1M?

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  7. hi, i also have a little distortion, any solution?

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  8. I have built this. Nice sound, not overly squishy, but I do have a bit of distortion when strummed hard using a Les Paul with handwound humbuckers. No distortion when single coils. I used bc338B transistors, as I'm out of bc550 & bc547 & other close equivalents, and I used a yellow LED + 1M dark LDR with a trim pot I stead of the 215 ohm resistor on the LED. I will try out some different transistors & different LED colors & vactrols I have, and report back.

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  9. Hola, it works very well but when using the 5534p it generated some noise, with TL071 no, but I don't know how the 100p capacitor affects

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