ZEN Instruments

 A friend asked me about adding CV and gate inputs to an Electro Harmonix EH400 Mini Synthesizer. Don't get it confused with their ...

     I developed this mod specifically for the Montron Duo, so that one oscillator could sync to the other. Since all three models of Monotr...

     I've been experimenting with Monotrons since around the time of the original's release. I took an interest in the Duo model mor...

 I stumbled across the VTech Precomputer 1000, learned that it's based on a z80, and looked for a schematic. I couldn't find one, so...

     Here's one more analog drum schematic that I've redrawn. I worked from the drawing found here , and changed the layout for clar...

      I added labels to the last of the three Monotrons, the Duo.

    I have a bit of a fascination with dub sirens. This one, the NJD, is particularly iconic. A schematic is floating around, but it's n...