If you have an old analogue monosynth, and require some means of playing it over MIDI other than through sampling the synth's sounds, a separate MIDI‑to‑Control Voltage (CV) converter is probably the best way to go, as this does not damage your treasured antique, as does a MIDI retrofit. There are the multi‑channel Roland MPU101 and Kenton Pro 2 (and now Pro 4) converters, but if you only have one synth to MIDI up, and resent paying for channels you will never use, what do you do? This is where the Missing Link comes in.
The Missing Link is a beautifully simple single‑channel MIDI‑CV converter made by a small Dorset company called CP Technology. To say that the casework is minimal is an understatement! The device measures a mere 140 x 80 x 34mm, and there is very little to set up other than the MIDI channel. It has just one MIDI In socket, one CV output, and two 3.5mm jack Gate outputs — one V‑Trigger output for ARP, Roland and Sequential synths, and an S‑Trigger output for Moogs. This means that virtually any old monosynth can be connected — except old Yamaha and Korg synths, which don't use the 1‑volt‑per‑octave CV system (a special version of the Missing Link is currently being developed to drive these synths). A tiny front‑panel rotary switch sets the MIDI channel for the unit. After that, assuming that suitable leads are plugged into the Missing Link and your synth, there's nothing to do! The CV provides the pitch information (there is a small front‑panel trimmer pot to tune the octave if your synth is less than accurate) and the Gate switches the synth's envelope generators on and off. Pitch bend information is also carried down the CV line, so no extra connection is necessary. Pitch bend is set at +/‑ 1 octave, but as I always use a pitch bend range of two semitones, I contacted the company prior to ordering to see if this could be changed, and my unit came shipped with pitch bend set at two semitones. Thanks to CP Technology for reacting so quickly to my needs.
Inside the unit is a high‑speed RISC processor which ensures minimum note‑on delay. I wasn't equipped to measure it, but I certainly couldn't notice it either, and sequenced analogue basslines sit with authority and precision against drums and other parts.
In conclusion, if you have an old monosynth that you want to drag out of retirement, or are thinking of buying one, at a mere £90, the Missing Link scores high for value and simple functionality. Dealers like DIN who specialise in supplying vintage gear would do well to get a stock in to supply as standard issue. Highly recommended! Steve Howell.