** Since writing this blog post I’ve made a free sample pack and a free Ableton Live pack which you can download here Free Ableton Live Pack #001 Circuit Bent Yamaha Pss 140 **
In this article I’ll show you how to circuit bend a PSS 140 Yamaha Keyboard to include:
8 x Data line switches
8 x Patchbay
1 x pitch bend modification (lowers pitch).
First a quick explanation of the Yamaha keyboard & the circuit bend, then on to the how to guide.

The Yamaha PSS140
The Yamaha PSS series offer us a range of cheap keyboards to start circuit bending. You should be able to pick up a PSS 140 for about £15 on eBay.
The Yamaha PSS140 features:
- 100 presets
- drum pads
- Auto accompaniment
- “rhythm section’
The rhythm section has a few beat types such as Waltz and Disco and the presets generally sound terrible! With some bending of the data lines we can create weird glicthy beats, odd FM breakdowns, blips and mayhem! Rather than creating a playable instrument this bend creates a complex sonic pallette ideal for sampling.