Negative modulation values

Negative modulation values
« on: January 08, 2023, 06:59:44 AM »
Hi,

I have tried the search but without results. So should this already have been discussed please let me know where.

When I assign the mod wheel as modulation source and route it to e.g. the AMP attack then the attack time becomes shorter when the value from the mod wheel becomes larger. The result is as expected when the modulation amount is negative. Why? Let's assume that the mod slot amount is set to +100. Then I expect that values between 0 and +100 will be added to the knob setting of the attack time. But on the contrary, the values are subtracted. Do I something wrong or is that so, why ever? Thanks!


Stefan
DSI Prophet Rev2

Re: Negative modulation values
« Reply #1 on: January 08, 2023, 11:44:49 PM »
Hi,

I have tried the search but without results. So should this already have been discussed please let me know where.

When I assign the mod wheel as modulation source and route it to e.g. the AMP attack then the attack time becomes shorter when the value from the mod wheel becomes larger. The result is as expected when the modulation amount is negative. Why? Let's assume that the mod slot amount is set to +100. Then I expect that values between 0 and +100 will be added to the knob setting of the attack time. But on the contrary, the values are subtracted. Do I something wrong or is that so, why ever? Thanks!


Stefan

I tried it on my REV2 and sure enough, the values from the mod wheel are inverted when sent to envelope parameters (A,D,S,R). Same thing with velocity as a modulation source sent to the attack knob. Seems like an undiscovered bug perhaps? In the manual, they state that positive modulation values will be added and not subtracted as the behavior observed.

I hadn't noticed this before, since I'd never used envelope parameters as destination before...
Oberheim OB-X8, Minimoog D (vintage), OB6 (Desktop), Oberheim Matrix-6 (MIDI Controller for OB6), VC340