How about a Geiger counter synth module? Nuclear Decay was designed by TimMJN and this is my version. It works, but if you want more than occasional blips from it, you may need something extra...

Links:

Music: Ringtone by Rich Holmes

Demo of some of the non-waveshaping uses for the Wave Displacer.

The Wave Displacer module was not designed to function similarly to a ring modulator. But no one told it that.

Demo of my Wave Displacer module's wave shaping and comparator features.

(Previously uploaded version had bad audio, this is better.)

BETTER VERSION HERE: https://diode.zone/w/tqqDZJUs7Fyu7b79hGALez

Demo of my Wave Displacer module's wave shaping and comparator features.

There's some nasty background noise audible here that seems to be an effect of the video encoding. It's not present in the original recording. Sorry!

This is a Kosmo format synth module built from a DSO138 digital oscilloscope kit. It's a basic but useful scope module you can build for about $50 or less.

Links:

Music: Ringtone by Rich Holmes

What happens when a sample of autunite gets close to a Geiger counter synth module?

Ringer is a Kosmo format DIY synth module built around the AD633 chip. If you need to you can press it into service as a 2-channel mixer or a voltage controlled amplifier, but what it really is useful for is something like ring modulation — combining two simple waveforms to make a much more complex sound.

Git repository: https://gitlab.com/rsholmes/ringer

Music: Ringtone by Rich Holmes

Analog Output blog, and links to other AO sites, here: https://richholmes.xyz/analogoutput/

Demo of the Ringer module as VCA, mixer, and "ring modulator"

A look at the Add Noise Drum, a Kosmo format analog drum module for tone and noise based drum sounds.

Git repository: https://gitlab.com/rsholmes/and

Music: Ringtone by Rich Holmes

Analog Output blog, and links to other AO sites, here: https://richholmes.xyz/analogoutput/