Green Dungeon Alchemist Laboratories
Photo Logic Multiplex

This is a simple sound machine, it works on a similar principle to my logic multiplex but with slightly altered functionality and greater depth of LFO control.

It utilizes a 40106 schmitt inverter to make 3 light controlled oscillators with LDRs (Light Dependant Resistors) and 3 LFOs which just use pots. These are connected to a 4051 multiplexor connected as a programmable gate or “ANY” gate. I had a DIP switch lying around in some old electronics which I used as the switches in the diagram below. Scavenged wood and metal were used too, for the box.

Sound demo


Circuit diagram

At the time of posting, this device is for sale here:

Ebay auction