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.

Tuesday, October 2, 2018

Catalinbread WIIO

The Catalinbread WIIO is a Hiwatt amp emulator specifically going for the sound of Pete Townsend's Hiwatts on the Live at Leeds album. (Throwing this and a Univox SuperFuzz in the same box would be a must if you're a big fan of the Who...) The topology of the circuit (cascaded MOSFETs) is similar to the zVex Box of Rock and Catalinbread's other Hiwatt emulator, the Rah. Here's the schematic for reference. Should fit in a 1590B just fine.


  1. Any reason 2n7000s can’t replace the BS170s?

    1. They don't quite have as much gain as the BS170, so they might work but it'd probably be a little quieter. You might need to rebias the transistors as well.

  2. Ive used 2n700s ,in the end went with BS170 socket ,reducing the 1k resistor to say 470R will give more gain,I built this and put it in with a super fuzz a few years ago also added a compressor for gilmore tone

  3. It Work, but I have a problem with the potentiometer of the bass tones it does not work. The range of action is really ineffective, rotating the sound changes very little, almost nothing. Has anyone problem?

  4. It works!

    I did find one possible error though: I think the "Bass" and "Treble" pots in this layout are swapped, at least according to all the schematics I've been able to find of this circuit (including the one linked, although it does not label them). I think "Bass" should be A500k, "Treble" should be B500k. It doesn't make a ton of difference, obviously, since they are both 500k but I figured I'd point that out since it does have an effect if you've got both set to noon and you're wondering why it sounds a little off. :)