Kenton Pro-Solo mk1 - Manual (Page 15)

IDI-CV converters can have up to four different types of outputs used
to control analogue synths, usually labelled CV, GATE, S-TRIG and AUX.
Below is a description of what they do;
Pitch - CV outputs (V/oct, Hz/V)
The CV (control voltage) is a voltage that tells the synth what note to play. Most synths
use the 1 Volt per Octave (V/oct) pitch scaling system to control the pitch. This means,
that each octave is 1V (V=volts) apart (or 0.0833V per semitone).
For example, bottom C (MIDI note #36) corresponds to 0 Volts. The next C will be 1V, 2V,
3V etc.. Synths using this system include Roland SH101, Sequential Circuits Pro 1, ARP
Odyssey, Oberheim OB 1.
Some other synths, most notably Korg and Yamaha, use a different pitch scaling system.
This is an exponential method called Hertz per volt (Hz/V). This means that for the next
octave up, the voltage is doubled. So bottom C (note#36) will be 0.25V, the next C will
be 0.5V, 1V,2V, 4V etc.
If you are not sure which C is MIDI note #36, use MIDI analyser mode to check.
If you use a Hz/V synth with a V/oct pitch output (or vice-versa), the synth will play out of
tune but will not cause any damage to the synth.
Note - The Korg Monopoly is an exception. Although other Korg synths use Hz/V scaling,
this synth actually uses V/oct scaling.
Gate - (Or S-TRIG)
The GATE (sometimes called V-trig [voltage trigger]) signal is a voltage that tells the synth
when to play the note. The GATE voltage will usually be a positive voltage when the
note is on, and 0V when off.
Some other synths, like Moog, Korg, and Yamaha, use S-TRIG (Short Trigger) instead of
GATE. This signal still tells the note when to play, but it is a different type of signal
(electrically). To tell the note to play, the converter will provide a short circuit at it’s S-TRIG
output (0V), and to turn off the note the output will be open circuit (literally like opening
and closing a switch).
A point to watch for; unless you know the synth, it will not always be clear what type of
CV and GATE signals are required to play the synth.
For instance, the Korg MS20 requires an S-TRIG signal, but the input is labelled TRIG.
Another example is the Yamaha CS5. The pitch input is marked CV, but requires a Hz/V
signal. The best way to check is either ask someone who knows, or just try all types of
output till the synth works correctly. If you do plug your synth to the wrong outputs, it
shouldn’t do any harm, although always start out with minimum voltages.
A BRIEF GUIDE TO MIDI TO CV CONVERSION FOR THE BEGINNER
M