Moog MIDI MuRF MF-105M Usage Instructions page 26

PEDAL INPUTS: All pedal
control input jacks are 1/4" tip-
ring-sleeve (stereo) phone jacks.
The sleeves are grounded and the
ring terminals are supplied with
+5 volts which is current-limited.
The tip terminals receive the
variable voltages from the pedals.
An expression pedal for use
with the MF-105M should contain
a 50KOhm or 100KOhm linear
taper potentiometer which is
connected from the sleeve to the
ring terminals. The potentiometer
wiper is connected to the tip
terminal. The pedal cable should be shielded, with the shield connected
to the sleeve terminal. See Figure 14.
When connecting one or more pedal control input jacks to a source
of external control voltage such as an analog synth or a MIDI-to-CV
converter, you should use patch cords with tip-ring-sleeve phone plugs.
The ring terminal on the plug should not be connected to anything, so
that the MF-105M's source of +5 volts is not shorted out. See figure 15
for a diagram. If you do not plan to use any expression pedals with your
MF-105M but would like to apply control voltages to one or more pedal
control inputs, you can use patch cords with regular two-conductor phone
plugs. These will short out the +5 volt supply to the ring contacts. This
voltage is current-limited, so you won't burn anything out, but no pedal
will work in any of the pedal control jacks if a tip-sleeve plug is plugged
into any of the pedal jacks.
Applying a varying voltage to the tip terminal of a pedal control input
jack has the same effect as turning the corresponding knob. On the MIDI
MuRF, with the knobs in the mid-position, a voltage change of 0 to + 5
Volts at the tip terminal is equivalent to turning the corresponding knob
through its entire range from full counterclockwise to full clockwise. You
can 'program' your MF-105M performance parameters entirely from
external control voltages, by turning the ENVELOPE, MIX, and RATE
control knobs to mid position, and feeding 0 to +5 Volt programming
Figure 14 - EP-2 compatible wiring,
Figure 15 - wiring diagram for using
external CVs with a TRS plug
page 26