And yes it can be a little noisy but a noise gate like the one from Ladik or the one in the FX Aid takes care of that easily. You may also be able to handle that by simply putting it in front of a VCA, depending on how you're using it. But anyway it sounds fantastic.
-- adaris
Actually, this is a major symptom of using either the wrong VCA or wrong envelope behavior. When you use linear VCAs and/or linear envelopes, this can happen because our ears aren't linear with respect to "apparent loudness". We hear exponentially as far as volume is concerned, and the Decibel scale reflects that.
The actual fix here isn't a noise gate (sorta-kinda), it would be one of the following:
Change the VCA after those filters. This needs to be an exponential VCA, or a "multi-topology" one like the Veils VCAs that's been set to exponential response. Or...
Keep the linear VCA...but send it an exponential envelope.
Now, the reason I said "sorta-kinda" above is because, when you do this correctly, it actually has some dynamics elements in common with a noise gate. The response of these VCAs when properly set is actually VERY close to the sort of thing going on with a noise gate, inasmuch as the noise will fall nearly to or all the way to inaudibility when there's no generated audio thruput.
Rule of thumb: LINEAR is for DC, low rate modulation signals, and basic audio use upstream from the final output stages. EXPONENTIAL is for any audio rate signal, and NOT DC or low rate modulation. Many exponential VCAs aren't DC-coupled, so if you try and pass DC or a low rate mod signal through one, you'll get either nothing or a very attenuated output signal as far as those signals go. Very useful to keep in mind when trying to keep DC out of your monitoring setup!