[sdiy] MIDI Velocity on analog synths

[MTG]

I have a couple of questions based on the helpful input from last week.

On 2/5/2014 7:05 PM, rsdio at sounds.wa.com wrote:
>
> I agree that it would be rather difficult to make the Pro-One ADSR
> respond to CV directly. You could implement a parallel digital ADSR in
> the processor, and sum its output on the VCA CV input, but that might
> require alterations of the ADSR settings when the user makes a patch.
> Also, I'm not sure whether digital ADSR would perform very well with a
> small 8-bit.

I'm not seeing a VCA CV input on the Pro One. It looks to me like each 
ADSR is set by 4 different pots (rather than the summing amplifier 
scenario of the VCF, VC0). Unless I'm missing something...

On 2/6/2014 2:05 AM, Tom Wiltshire wrote:

 > What the CEM3310 doesn't have that the CEM3312 added is the Level CV 
 > to avoid a separate VCA for amount control. On the Pro-One this isn't 
 > a problem, since it's not a programmable synth and the filter
 > envelope simply goes via a "Filter Envelope Amount" potentiometer. As 
 > Florian says, that would be the ideal destination for a Velocity CV.

To me that looks like an input to the filter and so how is that 
different than what I'm doing? I give the user CV control for the cutoff 
and resonance. I already planned to inject the velocity at those two 
places (under user selection of course).

Maybe what Brian is implying is that rather than impress a simple 
velocity value on the VCF, make my own ADSR that's influenced by the 
velocity and apply that to the VCF?

So I guess there is no easy way to control the ADSR's themselves or the 
volume without a fair bit of construction. So far the project requires 
only "wires and resistors" for the CV aspect (as far as carving up the 
Pro One is concerned no cuts on the PCB, etc).

GB