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!
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 Banzai, Das Musikding, Small Bear and some reputable Ebay sellers. ALFA RPAR recently released a CA3046 clone, too. The PCB also includes pads for SMD LM3046. Or, you can use a UL1111, which is functionally identical to a CA3046.
It’s the golden age right here!