Synth Patch Clickiness

On virtual analog synths, I frequently come across patches where there are noticible clicks between and during keypresses. I've found that there's two common causes for these clicks that can be fixed.

The first cause is an amplifier envelope with 0 values for the attack and/or release. When set to 0, a leading or trailing square wave is produced, causing the click. Adding a small value to these parameters won't change the basic character of the patch, only removimg the clicks by allowing a more moderate slope to the envelope, assuming that you don't actually want the clicks, of course.

The second cause is when you run out of polyphony. Most VA engines I've used will completely cut off the "oldest" note, causing a click. While you might not be able to always easily fix this, sometimes I find that the polyphony has been drastically reduced using higher unison modes. Reducing the unison to 2, or turning it off, will increase the poly and get rid of the clicks. Sometimes unison is being used even though the second and/or third oscillator isn't, so you can substitute a detuned oscillator and turn off the unison, while retaining or increasing the depth of the patch, yet increasing polyphony.

The amp attack/release envelope problem also occurs on full analog synths too.

Some of you may know this already, but I thought I'd mention it because I run across this problem so often. In fact, the reason I'm writing about this tonight is that I found some patches on my new X-station that had this problem that I fixed.

True. The Attack/Release thing is because digital envelopes are ridiculously fast. I mean, when they say 1 ms they mean 1 ms. On analog synths that wasn't nearly as fast. Lowest settings would be around 20 ms. Which is still almost instantly, so why not turning attack/release up a notch?

Then I stand corrected ^^'

An envelope with a 0 attack/release isn't really much of an envelope at all: it's a gate. The whole purpose of the envelope is to give a more natural curve than a gate. With a modular analog synth this becomes more apparent when you have to patch in the envelope to the amp gate to get rid of the clicks. The attack/release on the Buchla 200 also starts at 1 millisecond and causes clicks.

I found that the Prophet '08 was very prone to clickiness - I don't think it's just VAs...

Here's another situation that cause clicks related to polyphony. When a patch has a mono mode (vs. poly), even though the amp envelope may be triggered on each keypress, the note of the prior key is cut-off without a release, causing a click. Sometimes you need to stay in poly mode for the prior note to release according to the amp envelope. I just experienced this on the X-station, but I recall that the R3 does this as well.