Gated/Velcro Fuzz 101

[turdadactyl]

Can I get some hand holding?  I really like farty, velcro-ish, gated fuzz sounds.  I'm gathering that the typical way to implement this is to adjust the bias on the clipping stage of the fuzz circuit, for instance on Q2 in a Fuzz Face layout, so that it's "misbiased."  Can someone explain a little more the theory behind why/how this works?

I read this thread: http://www.diystompboxes.com/smfforum/index.php?topic=76383.msg664547#msg664547, which was somewhat helpful, particularly the schematic from Gus.  That said, I'd really like to get a more thorough explanation of the science here.

As an example, the Bearfoot Candiru is a killer gated sound.  I'd like to understand why that seems to be more gated than the original Candy Apple.  (Given, I haven't actually had my hands on either.)  However, my question isn't limited to that pedal and I'd like to understand it fundamentally.

Thanks, as always!

[turdadactyl]

You know you wanna chime in.

[kaycee]

I can't help with the theory, but would suggest you try the shin ei FY2, the FZ1A, Tonebender mk1 and of course the Fuzz Factory. There is a schematic for a silicon mk1 if you google, that's easy enough.

I expect that some of the Devi Ever circuits would fit the bill too, but I've not tried any of those myself.

[duck_arse]

search for the add fuzz to your electric guitar. it has a knob, ranges from cut-off to very smooth. and volume.