Would you clarify which ‘input’ you mean please @odevices? I’m assuming audio input, in which case sure!
Never thought of rectification that deeply before, but yes, that makes perfect sense - thank you once again!
My brain fizzes sometimes when I come here 
Yes, input means the original unadulterated audio input.
I been playing and thinking and finding things; if you use a relatively low frequency say 50-60hz for a simple bass sound sound… then yes, you do get stair casing!
An envelope follower after the S&H smooths it right back out though - weird, but it definitely kills those clicks!
I thought the point was to delay the gate on to the envelope to line up with a zero crossing and then leave the envelope in sample-and-holded(eg not staircased)
Yeah, I was thinking about this, too. Not entirely sure how it could be done (a gate is delayed, but not ignored, until there’s a zero crossing) but I’m sure one of these guys will come up with a solution 
Heh, this is fascinating!
I like the idea, surely you just use the same setup, but put the S&H setup before the Envelope not after?
The gate will be sampled at the very first zero-crossing and it will fire the envelope, no idea if it actually works or not, just need to try it.
Anyone at their rack now care to try? I want to know 
Hello. I’m hoping someone can help me figure out what I might be doing wrong or correct any misunderstandings I may have.
I’ve been searching for way to trigger and envelope 808 style bass drums on the 301 that don’t have a click at the beginning (actually any sound, but low bass is where this problem stands out most). If I use an envelope that is shorter than the time between triggers then I’m fine, but hopefully you can understand why that is not ideal.
So far the best solution I’ve come up with is to use an external envelope that can reset to 0 on receiving a rising edge no matter what (O_C in Piqued mode - but then there goes my damn quantizer). That solution isn’t perfect but it’s much better than an analog style envelope that picks up wherever it left off in the decay/release phase, but these resetting envelopes are a little harder to find (and again, it’s not a perfect solution).
So, I was thinking this kind of ZCD VCA is a solution for this problem? Is that the main purpose? To ensure clicks don’t arise? And that this S&H solution, though it will introduce stair-casing, that stair-casing should not have an audible impact? This is where I think I’m missing a step, but I’m getting super audible “zippering” - if that’s the correct term.
Here are some screens of what I have pieced together from patch notes earlier in the thread:
Top - “Env” is Linear Bipolar VCA:
Env (VCA) level subchain - A1 source is my external envelope
S&H trigger subchain
Here is an audio example of what I’m experiencing. The first two events are a sampled bass drum with an envelope that runs its course (so long enough for decay to reach zero before triggering the second time). After that is the same sound being re-triggered fast enough to produce clicks, and finally the same thing only use what I think is the S&H method.
Actually the “zippering” sounds kind of cool, but not for my bass drum purposes. What did I miss?