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, May 5, 2017

Hornby Skewes Zonk Machine II

The Zonk Machine II was the more budget friendly version of the Zonk Machine. It was a simplified circuit and featured silicon transistors in place of germanium. Originals used 2N4061 PNP silicons, but other could be used. Because it's silicon based, it shouldn't be too hard to make the swap to NPNs so it can be daisy chained with other negative ground effects. I've laid out 2 versions of this, one for BCE pinout transistors (like the original 2N4061s) and one for CBE pinout transistors. The perf layouts reflects the original positive ground configuration, and the PCB layouts reflect negative ground configuration. Note that the 3.9k resistor isn't always necessary (it's there to make the Fuzz pot value 2k). Here's the schematic for reference.

1 comment:

  1. EBC layout verified with negative ground.
    Used 2N2222's for the transistors and flipped all polarized components 180 degrees.
    It doesn't get much above unity volume even with the gain and volume controls maxed.
    I tried a 68K resistor in place of the 2M2 on the output, which increased volume but also added lots of idling noise and a weird gating effect.
    It's a decent fuzz, but probably not a keeper for me.