Polysynth AS3310 ADSR routing help

MichaelB · Joined: May 24, 2022 Posts: 2 Location: Leeds

I'm currently stuck on a problem and was wondering if anyone could help me out?
I'm attempting to make a polysynth and it's taking a very long as I think I've bitten off more than I can chew! Also I'm not that well versed in electronics and have a limited knowledge but I'm always trying to learn.

I'm using 2 x Midimuso midi to CV converters linked together to supply 6 separate gates/pitches outs. These control six individual identical voices (VCO, VCA, ADSR, FILTER, WAVEMULTIPLIER). The 6 separate voices outputs then go into a panner/mixer that's summed to Left and Right. Then this goes into another filter and finally a delay output. So far it works fine but is still very much a load of monosynths...

I want to have the option of using one master ADSR (especially sent to the VCA's) to give the sound more cohesion, using the gate input from Voice 1.
So when you press one key only the first voice will sound, then add another key and the second voice will sound - both following the master ADSR envelope. Obviously I need to switch these outputs otherwise all voices will sound even if only one key is pressed.
I thought about using the 2nd gate output CV from the midimuso to act as a switch to control a CD4066 and have the master ADSR envelope pass through the switch when a 2nd key is pressed. This works fine for shorter envelopes but cuts off the signal once theres no gate signal (key is released) so you miss out on any of the longer decays.
Is there anyway to switch this so that voice 2 will only sound when a second key is pressed and that it will follow the envelope of the ADSR completely - sustaining even when the key has been released?

I hope this makes sense...it's driving me a bit mad!

Blue Hell · Posted: Tue May 24, 2022 5:47 pm Post subject:

Hi MichaelB and welcome

I'm not quite sure what you mean .. maybe I did not read it well enough .. but I'd think .. if you are to have one master envelope .. you'ld want to trigger it from a logic or function of the gates of the voices?

I'm not understanding the switching bit - that is ... to me there seems to be a mixup in thought of having one or, instead, having several envlopes?

MichaelB · Joined: May 24, 2022 Posts: 2 Location: Leeds

Thanks for the reply Blue Hell!

Basically I want the option for each voice's VCA to be controlled individually by their own ADSR envelope or collectively by a master ADSR - which receives Gate 1 cv

https://ibb.co/LCnjr0J

I've built that using the CD4066 switch and it works fine, voice 2's VCA only opens when the switch is closed, passing through the master ADSR. The only problem is if the envelope has a longer decay/release then that gets cut off as the 4066 closes once there's no more gate signal.

Is there anyway of all the VCA's sharing one master envelope but to only sound when that specific gate is sent (key pressed) and for them to follow the envelope and not to be cut off when the gate goes low (key released)

I could get six separate AS3310's and have them all controlled by one group of pots...they're expensive chips though!

Hope that makes sense.