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



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10 comments:

  1. FacundoMay 30, 2016 at 12:43 PM

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

    ReplyDelete
  2. FacundoJune 2, 2016 at 1:09 PM

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

    ReplyDelete
  3. JiomyFebruary 5, 2017 at 7:29 AM

    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

    ReplyDelete
  4. Rosang pongenFebruary 9, 2021 at 9:46 AM

    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!!

    ReplyDelete
    Replies
    1. BiriguibousMarch 3, 2021 at 6:45 PM

      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.

      Delete
  5. Rosang pongenFebruary 9, 2021 at 9:47 AM

    And this is not OD it's FUZZ!!

    ReplyDelete
  6. Orang GilaSeptember 16, 2022 at 9:35 PM

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

    ReplyDelete
  7. Electric rotsOctober 27, 2023 at 12:53 PM

    Can i replace C1 with polar caps?

    ReplyDelete
  8. thunder sanchezDecember 19, 2023 at 11:21 AM

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

    ReplyDelete

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