Moog Music Forum

I'm thinking about building a simple controller but I need to know how much output current I need. In other words, what is the typical Moogerfooger CV input current/resistance?

Thanks.

From the MF-102 manual

PEDAL INPUTS: All pedal control input jacks are 1/4" tip-ring-sleeve phone jacks. The
sleeves are grounded and the ring terminals are supplied with +5.7 volts which is
current-limited to about 0.5 milliamperes. The tip terminals receive the variable voltages
from the pedals.
Figure 11 - Correct wiring of an expression pedal for the MF-102.
An expression pedal for use with the MF-102 should contain a 50KW or 100KW
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.
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-102's source of +5.7 volts is not shorted out.
Figure 12 - Correct wiring of a tip-ring-sleeve plug for connecting a pedal control input to a source of external control
voltage.
Or, if you do not plan to use any expression pedals with your MF-102 but would
like to apply control voltages to one or more pedal control inputs, you can use
patch cords with regular two-conductor (tip-sleeve) phone plugs. These will short
out the +5.7 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 even one 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. A voltage change of about
5 volts at the tip terminal is equivalent to turning the corresponding knob through
its entire range. You can 'program' your MF-102 entirely from external control
voltages, by turning all four control knobs (but not the DRIVE knob)
counterclockwise, and feeding 0 to +5Volt programming voltages to the tips of
the four pedal control input jacks.

I'm afraid the manual doesn't answer my question. I'm going to be connecting my CV output to the pedal input between the tip and sleeve (ground). So I'd like to know how much current the tip input will draw.

I won't be using the ring 5.7V at all - that's intended for use with passive expression pedals.

Think about it this way... the ring contact is designed to power a passive expression pedal, whose output is feeding the CV input the same way you want your controller to feed the CV input. In the case of the passive expression pedal, 500 microAmps will do the job. So in your case, 500 microAmps should also do the job. Sound logical?