Handmade XORium iteration 3 noise synth with XOR, VCO, freq divider 2026

ig @biokodein

XORium synth is an ongoing project, this is the third version of CMOS synths which is more of a prototype build as there are three different boards inside.

The core of the synth is six oscillators made with 40106 which interact through diodes and are then mixed via XOR gates. Frequency of the oscillators is set with the six knobs on top. The resulting signal goes to a simple VCO built around 4046 PLL chip with switchable capacitance on the input and range capacitor mod controlled with the single pot on the side of the synth. Trimmers on the board control the range, feel free to tune them to your liking, just maybe note the original setting. The signal from the VCO finally goes to the frequency divider board with 4040 counter. The two pots next to each other are voltage starve controls for the 40106 and XOR chip.

The buttons and switches work in the spirit of circuit bending and are made individually for each build, there are solder points for easy access to the connections, you can change them or add more (if you know what you're doing). Some change the range of the oscillators, some attach or detach diodes, some just short out some spots on the boards.

What they do to the sound depends heavily on the position of all of the pots, therefore the style of playing is dynamic and collaborative with the machine itself, first you tune everything to find a sweet spot you like and you find out what the buttons do. Then you change stuff slowly and see if the synth will fight back.

9V battery inside, guitar jack out.

DM for shipping if your country isn't listed. If you want insured shipping, it's 12€ extra.

(Reclaimed casing from the 70s, the paint is chipped on couple places and one of the screwholes is messed up)