Roland 100M VCO adapted to Euro with extra features.


For this item we offer a CHIPSET which contains the following:

For all other components required, please see the build document.


XVCO TWO is essentially the Roland 100M VCO adapted to Euro.

There are individual outputs for ramp, square and triangle – an improvement on the original. The six position rotary switch for octaves gives the oscillator plenty of range, with a pitch control to fine tune. An internal LFO (thanks MC202) can be used to introduce FM and/or PWM. Super!

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

Care has been taken to set XVCO TWO so that it needs only minimal tweaking of the trimmers for scaling. It’s easy to set up without recourse to ‘scopes, frequency counters, and precision reference oscillators! Accurate up to 7 octave too!

For DIYers:

The Roland 100M required the hard to find – but easy to fake – UA726. We’ve replaced that with a heated CA3046 with no loss of performance, meaning that there are no hard to find parts whatsoever if you are wanting to DIY the XVCO TWO yourself. CA3046 can be acquired from suppliers such as BanzaiDas Musikding, Small Bear and some reputable Ebay sellers. You can also opt to use the SMD LM3046 which the PCBs has pads for. Or, you can use the UL1111, which is functionally identical to a CA3046. ALFA RPAR recently released a CA3046 clone, which can be used instead – we sell these, and you can choose to buy one with the PCBs as an option when ordering.

It’s the golden age right here!

Product Specifications





12V draw


5V draw


-12V draw