AVRSynth is a monophonic "virtual analog" synth based, originally, on the Atmel AT90S8535 microcontroller and was designed by Jarek Ziembicki. His aim was to check to see if a simple micro could be used for sound synthesis purposes. And the result? The AT90S8535 managed to do all the tasks: front panel switches and pots services, receiving and processing MIDI messages, and sound generation!

The synthesis architecture is simple:- two DCO's, a DCF, and a DCA. There is also an LFO and an AR/ASR envelope generator.

Since this initial design was made we have taken over the project and updated the hardware to take the ATMEGA16 as the AT90S8535 is no longer a production item.

AVRSynth was also released as a full unit in a small desktop case utilising a PCB Front Panel. Later the panel design was updated to a quality aluminium panel.

The AVRSynth comprises 2 PCBs:-

1. Controller PCB
2. Carrier PCB. This PCB accepts all the panel components and so virtually eliminates all wiring

The Controller PCB is available both as a kit and pre-assembled and is ideal for those wishing too provide their own enclosure/front panel and/or wishing to experiment with the code (written in Assembler).

Build Guide

Schematics

Source Code