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Philip Rees Little MCV

MIDI-CV Converter By Derek Johnson
Published January 1997

Philip Rees have added yet another useful little box to their range of MIDI problem solvers. Derek Johnson gets converted.

Interest in pre‑MIDI monophonic synths just doesn't seem to be going away. An inevitable offshoot of this state of affairs is a niche market in interfaces that allow modern MIDI equipment to communicate with vintage gear. While Kenton Electronics arguably dominate the market in MIDI‑CV converters in the UK, there are a handful of other companies offering alternatives, and one such is Philip Rees Modern Music Technology, who are better known for their useful range of MIDI Thru, merge and switcher boxes. They now also produce a pair of MIDI‑CV converters — the £189.95 MCV, and the single‑channel Little MCV. The latter is particularly noteworthy, since, at a recently discounted £75.95, it is probably the cheapest MIDI‑CV converter currently available in the UK.


The Little MCV comes packaged in the familiar Philip Rees red and black livery, and uses the same style of box that houses other items in the company's range — there's even an internal power supply, as with many Rees products. Connection is simple: plug a MIDI cable from your keyboard or sequencer into the MIDI In socket at the left, select a MIDI channel with the 16‑position knob on top, and connect the control voltage and gate output sockets at the right to the relevant inputs on your monosynth. Note that the Little MCV lacks a MIDI Out or Thru socket, which means that it would always have to come at the end of a MIDI chain.

Different synths use different CV and triggering standards, so the Little MCV provides a pair of switches to make your choices. One selects between the fairly common logarithmic (volts/octave) CV standard, as used by Roland's SH101, and the linear (volts/hertz) CV response, used by some Yamaha and Korg synths (including the MS20). The other selects one of three trigger output types; most synths work with +5V, but some (my Moog Prodigy, for example) need +10V; an S‑Trig negative trigger option is supplied for synths — some Moog and Korg models — which require it.

The only other controls are a pair of miniature potentiometers, accessible with a small screwdriver, labelled Tune and Trim. These need to be set before you start using your Little MCV — it's fiddly, but at least should only need to be done once. The tuning range is about four octaves; tweak this control when your synth has warmed up, so that its tuning is stable. The 'Trim' pot is discussed incoherently in the manual, but basically sets the octave 'width' of the CV output, so that it's in tune across its whole range. This isn't as fraught as the same procedure on a monosynth, since once one pair of octaves is right, the rest of the Little MCV's range is automatically in tune too.


In addition to these few controls, the Little MCV has a number of hidden features, accessible only via MIDI. As well as responding to a 128‑note range and accurately tracking pitch‑bend information, it has an inbuilt LFO, which responds to the attached synth's mod wheel, adding vibrato to the CV output. Pitch‑bend range and LFO speed can be altered, but only via MIDI control changes. The same goes for a number of other features: legato, portamento, and a variety of sustain modes are handily available, but only if you can generate the necessary controller info, either from within a sequencer or from a smart master keyboard, to turn them on or off. Of course, a mixer map, of the kind available in Steinberg's Cubase, could be customised to give you control. Those with simple MIDI setups will have to improvise in some way.

The manual is a definite let‑down: all the necessary MIDI information seems to be provided, but it's often confusingly expressed. Some sort of table, listing continuous controllers against the parameters they control on the Little MCV, would have been very welcome.


In use, the Little MCV offers accurate, reliable CV and gate conversion, and is basically simple to operate: you could just plug and go, if you like, ignoring the extra MIDI‑accessible facilities (though you still have to spend a couple of minutes with the Tune and Trim controls). It lacks some of the sophistication of the Kenton interfaces — there's no auxiliary CV output or display, no power switch, and the LFO is fairly simple, for example — but still has plenty of extras, even if they're only accessible with MIDI controllers. For the money, however, it's hard to fault. If you've just bought your first (probably inflated) monosynth, and are feeling a bit tender in the wallet area, the Little MCV is currently the cheapest way to give it MIDI capabilities.


  • Easy to use.
  • A choice of linear and logarithmic CV conversion.
  • Internal PSU.


  • No extra gate or CV outputs.
  • No MIDI Thru socket.
  • No power switch.
  • Hidden MIDI functions.


Affordable, easy to use, and potentially sophisticated (given a modicum of MIDI elbow grease), the Little MCV fits nicely into Philip Rees' range, and even better in the analogue synth‑equipped studio.