@caowasteland Canyou provide a VCV Rack patch please? Then I could exactly repoduse what you did and where your problem lies.

Pitch-CV in general says that there is 1 Volt increase/decrease per octave.

The question is: What frequency in Hz corresponds to 0 Volt Pitch-CV?

For VCV-Rack found the answer in the VCV-Rack itself by looking at the V/Oct output of the MIDI-CV module, and it turns out that 0 Volts corresponds to the MIDI key 60, aka ‘C4’, and that is defined by 261.6256 Hz.

In my module for frequency shifting Pitch-CV values, I provide a root octave selector to make it possible to give another meaning than ‘C4’ to the value of 0 Volts. It’s an octave selector, so you can choose from ‘C0’ up to ‘C8’. It’s not possible now to set it to e.g. ‘A4’ (440 Hz), but there’s no need for doing that, because when you input a Pitch-CV value of 0.75 Volts (that corresponds to ‘A4’ and 440 Hz) and you apply an increase of 0.5 Hz, you will get out the Pitch-CV equivalent for 440.5 Hz. If you input 1.75 Volts (corresponding to ‘A5’ and 880 Hz) you will get out the Pitch-CV equivalent for 880.5 Hz (and not 881 Hz).