The Midimuso CV-12 ORAC kit

PCB assembled

This kit can be built for less than £20.00

You just need to order 3 items: the IC, the PCB and the parts – see the Shop page.

MIDI to CV converter using the Moog Volts / Octave CV scheme.
This board can produce
1V / octave or 1.2V / octave or 0.5V / octave just by setting the trimmer.


The Midimuso CV-12 Octex (fully assembled)
It’s just like the ORAC but has 8 sockets on board which can be patched by the user.

CV-12 Octex
CV-12 Octex
Octex in 4 note poly mode
Octex patched for 4 note poly mode

LEDs show signal sources and destinations

Octex LEDs
Octex LEDs show where signals are

Here’s a video of it in operation

The IC which makes it all happen….

How does it work?
The CV-12 IC translates MIDI into gates and control voltages.
MIDI is fed in at pin #2 and the IC produces 18 separate voltage outputs which can be used in new designs or retro-fitted to a synthesiser.

The outputs include:
Note Gates
(max 11)
Aftertouch (channel pressure)
Auxiliary Gates (max 11)
Midi Clock (CT)

Here’s the CV 12 Manual





Completed PCB for the CV-12

Socket boards are now available for this board allowing easy connection of 3.5mm jacks (compatible with the Octex too) – see the shop page.



Here are the CV-12 PCB  Instructions

Here is the manual for the NEW CV-12 Octex board

And the .mid files for easy program changes for both boards:


Connecting musicians and machines