Crumar Bit One MIDI Upgrade

Introduction

The Crumar Bit One is an underrated but very capable 6-voice polysynth from the mid 1980s. It has a great sound, backed with Curtis filters, cool industrial design and a velocity sensitive keyboard – which can be assigned to the usual envelope intensity as well as rather more unusual things like the ADSR attack times, LFO speed and pulse width. Although it shipped with MIDI capability, it is very limited.

Instead of being a software modification to the synth, as is usually the case with these kinds of projects, the MIDI upgrade takes the form of a daughterboard that installs neatly inside the synth, with its own microcontroller to perform its functions. The synth's existing circuitry and software is left exactly as it was, the new hardware integrates around it.

The Bit One's tape mode has been repurposed to work also as a setup mode for the MIDI upgrade's extended features, which are controlled with notes on the keyboard - no drilling or case mods required!

The MIDI upgrade provides the following improvements to the synth :

Note that the current version of the MIDI board's firmware is not compatible with the new Tauntek synth firmware, although I am working on resolving this.

Downloads

Photos