When I first became interested in modular synthesis I bought one of these, and liked it so much I bought another! The A-110 is probably the cheapest vco available, but delivers a decent audio performance, and offers a wide sound palette. It is saw-wave based, and offers another three wave shapes: sine , pulse and triangle. CV baed modulation of frequency and pulse width is available. According to the manual, the sine and triangle waveforms are not true, but derived from the saw wave. In practice all the waveforms sounded good to me. A pair of A-110's track very well together, and deliver good hard sync and FM results.
Other things I liked about the A-110:
* it was well calibrated on delivery and it achieves stable tuning within 5 minutes.
* At 10HP it is perhaps wider than it needs to be, but the control knobs are easy to use.
Room for improvement:
* The fine tuning range is not enough to tune one A-110 a musical interval above another vco, for instance a 4th or a 5th. I understand that there is a modification that can be made to the circuit board, but I feel the module should come set up this way.
* The A-110 cycles down to 15hz, which is not quite low enough to act as an LFO.
However, for the price this VCO is an absolute bargain. I bought the A-110 as a 'starter' vco, thinking I would sell or trade it when I could afford a more expensive vco. Instead I kept it, and bought another.
