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CV In Max/Min Voltage Inoperative

Posted: Sat Dec 19, 2020 5:14 pm
by devnull
Settings>CV Inputs has Max/Min Voltage on CV Inputs. The values appear to do nothing on Exp In 1 and I assume other CVs as well. The manual says that you can set the range , and that making Max < Min would invert the setting value transmitted.

I'm using a Moog EP-3 pedal in EXP 1 input. The EXP In 1 menu shows the voltage sweeping from about 0.070V to about 4.909V with the pedal knob fully clockwise.

When I use EXP1 as a modulation source, it behaves as if 0V would be 0% and 5V would be 100% (i.e. it is unipolar). Changing the values of Max Voltage In and Min Voltage In has no effect on the voltages read on the display or the behavior of the modulated destination.

INIT Patch
Modulation Matrix:
Source: Exp1 2.19%, Controller: Mod Wheel-100%, Transform: - Destination: All OSC-Patch LFO 1 AMT

a) Setting the Mod Wheel to full off - C3 note has no wavering.
b) Setting the pedal full off and Mod Wheel full on - the note wavers a little.
c) Setting the pedal full on and Mod Wheel full on - the note wavers intensely.

So the pedal at full off does not result in a 0% source input which is not surprising given the input is not 0V.

I would say the CV IN Min/Max Voltage should work as follows:

Set CV In Min to the minimum voltage your pedal generates or a little higher.
Set CV In Max to the maximum voltage your pedal generates or a little lower.
This should result in you getting full range of the pedal producing the effect of a modulation input change from 0% (pedal full off) to +100% (pedal full on). Reverse Min and Max values should get you a modulation input change from 0% (pedal full off) to -100% (pedal full on).

Specifically the Modulation Source value from a CV input should be calculated as:
Vin = Voltage of CV Input
Vin = Min(Vmax, Vin)
Vin = Max(Vmin, Vin)
Modulation Value(%) = (Vin - Vmin) / (Vmax-Vmin)

This would be a unipolar value in the range of 0 to 100% (Vmax > Vmin) or 0 to -100% (Vmax < Vmin).

As a workaround, I've used:

Exp 1: 8% / Controller: Constant 2% / Transform: Diode (S-C) / Destination: Pitch LFO 1 Mod

But then I need to burn a variable if I need an actually controller or transform.