Re: DIY fader automation interest ?
« Reply #140 on: April 19, 2017, 11:07:58 AM »
Hello

Some update

VCA's finally wired to the system  8)
I decide to only involve 8 CV to drive the 12 VCAs, 4 VCA "mono" and 4 VCA "stereo" (linked CV by pair)
So now in addition of 16 motor fader I have patchable VCA (for stereo channels or anything I want to automate).

As it is implemented in the exact same manner as faders (same 12bit DAC, same pcb) and with the use of dedicated map at software side, the tracking between passive (motor) fader track and VCA is supper accurate... as the VCA gain which I set like a fader, -100dB to +10 dB.
The math give 110dB/4096(12bit)=0.027dB steps, which is more or less what I can measure when the DAW allow so small adjust (top of fader)

Test with stereo material, L with VCA insert post fader, fader at unity (no motor engaged), R with motor fader.
Both grouped at DAW side so when I move motor fader the VCA follow. I can't ear any pan shifting  :)
With very fast automation (bellow 100ms full travel) the fader is 10 time slower than VCA so there is  a fade delay between track's.
It's possible to solve this at soft or hard side to slow the CV ramp driving the VCA, but I won't do it, fast VCA can be usefull for fast dynamic automation, like tremolo, rotary pan, pattern gate, and maybe "creative" compression as I can trig midi at DAW or with my DS301 (have to test this !!!) and for normal volume automation I don't go so fast so it's fine to me like this.

Best
Zam