Gator - regular old noise gate?

[blackieNYC]

http://gaussmarkov.net/layouts/gator/gator-schem.png
The Gator - I am very interested in the swell effect, but can this be a good general purpose noise gate?  I think I've read of a very fast release - must be great for swells but not so great for noise gating.  Can I get both functions out of the Gator?

[Mark Hammer]

Yes.  In fact, all it is, really, is a gate with a slow enough onset available that it can "gate" slow enough to be considered a swell effect.  If you find it not fast enough for your gating needs, change C8 from 10uf to something lower.

[blackieNYC]

Thanks Mark. Since I think you have mentioned these ideas before, a couple more:
End of chain or head of chain capable?
And, can it be tweaked into downward expansion? To have it not shut off completely, can you suggest a mod possibility?
How about filtered gating? Can I get it to notch out a buzz, or reduce the highs more than lows? 

I know these may interfere with the ability to swell, but I would consider making these features switchable.

[Mark Hammer]

First, let's distinguish between what makes it gate, how it gates, and what it gates.

Changing what makes it gate is a function of changing the input to the sidechain.  But the stock circuit gates the entire signal/spectrum.  Gating *some* of the spectrum would be a lot more complicated.  I'm guessing that you'd want to insert something between the input buffer stage and the OTA that would split the audio signal into the desirable and undesirable parts of the spectrum and then mix what gets gated and what doesn'tget gated after the OTA.

My sense is that other designs would be more hospitable to those goals.