I always wanted to build the Jürgen Haible Living VCO, but due to Jürgen’s untimely passing (RIP, Jürgen!), could not acquire the original PCBs for more than 2 years and finally decided to create a set of PCBs to use with the faceplate designed by Dave Brown with minor modifications (including the “PUSLE3” typo)
A few JH LVCO PCB sets are still available, please contact me if you are interested.
This is one VCO per board design with separate driver board and onboard potentiometers:
JH LVCO PCB set:
Schematics changes from the original
The Oscillator board:
- replaced CA3046 transistor array with THAT300 for more accurate tracking
- added an onboard amplifier to bump saw and pulse waves amplitude to +/-5V
- added optional oscillator sync input and output
- added optional thermo-compensation circuit (similar to Doepfer A-110)
The driver board changes:
- added three input mixer
- added saw to triangle converter
- added triangle to sine converter (Rev:A)
- 91A1A-B28-B20L — 100K Linear ( 6 x per VCO + 3 on the driver board, 21 total)
- 91A1A-B28-B15L — 10K Linear (2 on the driver board)
- 91A1A-B28-D25L — 1M Audio (1 on the driver board)
- M2013ES1W01-RO — On-None-On 1 per VCO (saw, off, pulse) and 1 for the driver (+1oct, normal, -1Oct)
Front panel: 4U DJB-LVCO3 Front Panel
IMPORTANT! Rev.A driver PCB has a silk screen bug: the value of R46 resistor is specified as 100K instead of 10K. Please install 10K resistor there.
Triangle to sine converter calibration: use 200 Ohm trimmer to tune output sine wave to a minimum harmonics (cleanest sound), them use 50K trimmer to set the output sine wave amplitude to 10V peak to peak.