Here’s the Roland 100M VCO adapted to Euro. The hard-to-find/easy-to fake ua726 diff pair has been replaced with a CA3046 with no loss of performance. No hard to find parts whatsoever. CA3046 can still be got for some suppliers such as Banzai, Das Musikding, Small Bear and some reputable Ebay sellers. http://dsmcz.com/prestashop/en/ sell UL1111 for only £1.53, they are functionally identical to CA3046. Alfa Rpar will shortly be releasing a CA3046 clone. The PCB also includes pads for SMD LM3046. It’a the golden age right here.

  • A six position rotary switch for octaves gives plenty of range. The PITCH pot is fine tune.
  • Individual outputs for ramp, square and triangle – an improvement on the original.
  • built in chip heater to keep you nice and stable in this topsy turvy World!
  • Onboard LFO! Yes that’s right, an onboard LFO (thanks MC202) for introducing FM and/or PWM. Super!

I’ve spent a lot of time tweaking the levels of the waveforms relative to 0V to take into account Euro’s +/-12V supply (versus the 100M’s +/-15V supply).

I’ve also taken a lot of time to set it up so there should be absolute minimal tweaking of the trimmers for scaling etc. Really easy to set up without recourse to ‘scopes, frequency counters and precision reference oscillators! Accurate up to 7 octave too!


XVCO TWO panel (10HP): £15 GBP

XVCO TWO Build Doc

For orders and queries please contact me at:

[email protected]


Here are the build docs for the previous versions (hey you backlog!):

XVCO Build Doc

System X Oscillator Build Doc

System X VCO Tempco Build Doc