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.

Friday, April 22, 2016

Cornish G-2

Happy Fuzz Friday, everyone! As promised, here's my layout for the Pete Cornish G-2. The circuit is essentially a Big Muff (with a few different component values) with a simplified tone stack and input buffers. It's not quite as fuzzy or distorted as a typical BMP but more of a heavy overdrive. Though it can get fuzzy at higher Sustain levels. There is a bit of uncertainty over the type of diodes used in the clipping stages, so socketing is a good idea here. 1N34s or 1N60s are a good place to start.

As I mentioned earlier this week, I've also laid out the bypass buffer with a board mounted footswitch. It's a little too wide for a 1590B, but this and main circuit layout will fit very nicely in a 125B enclosure. 

If you're building on perf and want to include the bypass buffer of the original you can use the Cornish Buffer layout and wire it like this:


  1. Hello friends!!
    In the first attempt of construction of the G-2, the volume is very short, has little sustain almost they have to be all controls to maximum to sound good and would fail sustain.

    1. Try increasing the sustain and volume pots to 100k.

  2. Thank you for your layout. You have done it again. I love this layout. I have a question regarding the diodes. I see that you recommend 1N34's or 1N60's. I used 1n270's and it really sounds muffish. Will the 1N34s or 1N60s get me the tone that I am looking for in a G2? I am trying to get the David Gilmour G2 tone with delay. Can you elaborate or give more information. I will post a picture when I am completely done. I really appreciate your assistance.

    1. I'm not sure that the diodes will reduce the muffiness all that much. Can't hurt to try out different ones though. Check out the FSB thread on this circuit. Lots of info there.

  3. Dennis FoxMay 17, 2016 at 10:14 AM

    Thank you for your response. Here is my current build that I have not finished boxing. I am currently using my testbox to play through it for testing purposes. This combination is a combination of 1n270's and Russian Germaniums. I will try 914's on it later maybe with bat41's and let you know how it goes. Thank you again.

  4. I just finished the G2. I really am liking it. I decided to use Russian Germaniums on stage 1 and 4148's on stage 2. It really is sounding pretty good. Here is a picture. Thank you again.

  5. Thank you for the complement. I forgot to say that the Russian Diodes are D9E's. D1 and D2 are D9E and the 4148's are D3 and D4.
    The following talks about different variations of Germanium and Silicon for G2 which is a Big Muff Hybrid.

    I hope that this helps other builders as well. Thank you again for all that you do.

  6. Hi, is this layout verified ? i saw some success builds on the comments, but not sure. Thanks.

  7. Guys,

    My G2 is very responsive to "bass"...
    And the tone control with little treble response ... this is my big problem (but, it responds better with the max button) ...

    Please, any of the friends can tell me... what can I replace to lower the bass response ... and improve the tone control range treble response

    I have tried other potentiometers ... Still, it did not get better .... maybe the solution is to replace values of some caps or resistors... But which ones?

    The pedal is very good ... I tested with: 1N34, 1N60, 1N270 X 4148, BAT46 .... I liked more of the 1n270Xbat46 and 1n34xbat46 ... but bat46 has less volume than the 4148.

    To be incredible, I need to solve this excessive bass ... and improve the range of tone control