Jürgen Haible Living VCO

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:






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)

Schematics: jhlvco  jhlvco_drv  jhlvco_con

PCB: jhlvco_pcb  jhlvco_drv_pcb

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.

29 thoughts on “Jürgen Haible Living VCO

  1. Hello,
    First of all I would like to say that you did an amazing job building this VCO!
    I’m building a Modular synth as well but I still don’t have an oscillator.
    I Really want to build it too, do you have (and like to share) the Eagle .sch/.brd files for this one?
    And where did you get the that300?

    • Sorry, I will not release Eagle files for JH LVCO until situation with Jurgen’s heritage is resolved and they will make original boards available for sale.

      THAT300 are available from Mouser, PN 887-340P14-U.

      • Thanks for the respond! I’m sorry for sending the message twice thought the first time it wasn’t working.
        No problem i’ll make one myself then, thanks anyway!
        p.s. the ca3046 is available at tayra-electronics 😉

      • Yeah, it’s still available here and there, but the stock will eventually run out, so it’s better to leave it to old designs that require them. Also, using THAT-300 results in better tracking.

  2. Any of the vco’s left? I just want a single vco without the driver board. I can incorporate the vco into my system without your driver board, right?

  3. Hi Peter! That would be great! I guess the front panel should be modified or an aditional panel should be added to hold the new waveform outputs, right? It is a new converter you are designing or something based on a particular vintage synth? best!, G.

    • I’m thinking of an additional panel htat would hold tri/sine outpus with level knobs as well as osc sync jacks. BTW, the revised JH LVCO Driver boards were ordered today, hope to have them back in a couple of weeks.

  4. Hey, do you still have one set in stock?
    I would love to build one of these and your layout is smart.
    Kind regards, M

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