Moog unipolar vs bipolar CV

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1

Hi all,

I have been wondering about this for a while. It seems that most CV inputs on Moog gear (aside from the Voyager?) respond to a unipolar signal of 0-5V; however, the CV outputs are in general bipolar. I understand that sending a 0-10V signal to a 0-5V input would be a bad idea, but what about sending a +/-2.5V LFO signal, for example (or even a +/-5V signal, like an oscillator from the Mother-32 into the MF-101 or Sub 37 filter cutoff)? Will the negative voltage cause harm? I usually just use an attenuator, and make adjustments until I get the sound I want. But should I theoretically always be using offset as well whenever sending bipolar CV to a unipolar input? I am not using any CV from non-Moog gear, so I assume they are generally designed to interact with each other without causing damage? I only have one CP-251, so it would be very limiting to have to use its mixer any time I want to send a CV signal…

2

Always check the manuals to get proper CV ranges. But in general negative CV is no problem. Normally knobs on MFs will act as an offset when a CV is plugged in, so a bipolar LFO (most MF LFOs are bipolar IIRC) will sweep above and below this setting.

From memory, I think you can apply a negative offset (to -5V?) to the Freqbox’s freq setting and it will put the oscillator into LFO mode.