This circuit takes a continuously variable dc voltage and outputs only voltages related to each other musically, using the 1v/octave standard. It utilizes a preprogrammed PIC which is included with purchase of a PCB. It is has a very low parts count, requires no calibration, and is small enough to be used either as a seperate synth module or as a daughter board to be attached to the input of an oscillator or output of a sequencer/s&h/other cv generator.

For schematic, bill of materials and theory of operation for newer boards, download this PDF file.  
For Troubleshooting common problems see this page.

If you have a rev 2.0 board, here is the old documentation on that.
If you have a rev 4.0 board, here is the old documentation on that.

Price for 1 board and 1 preprogrammed PIC $14.
The current batch of boards are revision 5.0 with Eurorack and MOTM power connecters, but no mounting holes. If you need mounting holes, I have a small quantity of Revision 4 boards available, just let me know when you're ordering if you'd prefer them.
There are unfinished Eurorack panels for building a dual CV quantizer. The layout is like the one pictured to the left but with added switches for selecting banks of notesets. The panels are $6.5 each, and there is more information here.
If you're interested in drillling your own panel, free free to use my drill guide here. That file should be printed at 300dpi for proper scale.

Email to place an order.

Full Kits for CV Quantizers from Synth Cube
A thread on the Muffwigglers forum where people are sharing front panel designs for building this in Euro format
A very long thread on Electro-Music where I initially announced these boards for sale