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.

Monday, November 9, 2015

TubeSound Overdrive

Here's a simple one-knob drive that's ripe for modification. It uses an interesting combination of one NPN and one PNP silicon transistor stacked together. There are a few different values you can tweak to taste. Here's a schematic for reference:

  • The input capacitor (C1) could be increased for more bass.
  • C2 could be increased to 47-100µF for more drive.
  • The output capacitor (C3) could be decrease for more treble.
  • R5 could be replaced by a 10-20k pot, lug 1 going to ground. C2 could then be moved between lugs 1 and 2. This would act as a gain control (much like in a Fuzz Face).
  • R3 (trimmer) could be moved off-board as an alternative bias/gain control.
I haven't tried these modifications, but they should do something interesting. YMMV


  1. Agradable sonido! C1= 33uf. C2= 6,8nf. Trimmer 22k. De esta forma me parece mas metálico y valvular. Verificado en Benavidez, Argentina.

  2. Perdon! C1: 6,8 nf. C2: 33 uf.

  3. Hey! Is there a place where i can find more info about this layout-schematic?
    Maybe a video where i can hear this pedal?
    thanks in advance

  4. If anyone wants to try this circuit.., remove 10k and 22uf from emitter to ground or else this circuit will not work
    Connect the emitter pin directly to the ground!!

    1. Hi Rosang. For me, it worked with the 10k resistor and 22uF capacitor, but the biasing is a bit hard to get done. Once you get the bias trimmer on the right spot, it gets a very good overdrive sound.

  5. I'm using pair of BC357 and BC337, it's working too. Just find matching pair of npn and pnp.

  6. If i change the r5 to pot iss lug 3 goes to input?