Help understanding fuzz control on Hot Silicon

[mark2]

This is a really noisy pedal. To lower the ceiling of the gain I added a trimmer wired as a variable resistor between C5 and the Fuzz control. It works to reduce the noise floor, but I don't have a strong grasp on how this control works (i.e. I just worked backwards from a fully clockwise control).

Can anyone shed any light on the principles of how this fuzz knob operates? Edit/Update: I realize now this is the same architecture as the Fuzz Face, so I'm going through an analysis of that.

And secondarily (much less important), any other tips to accomplish noise reduction / gain reduction?

[PRR]

> same architecture as the Fuzz Face

But with WAY more gain. 10X in front and it's lost the 10X divider at the end.

Maybe you just want a FuzzFace?

[ashcat_lt]

Edit - Somebody (who posted just before me) once said "everything useful is a voltage divider". 

When the transistor looks like an infinite resistance, there is no division of the power supply.  (Ignoring loading downstream...) The output is the full positive battery voltage. 

When the transistor looks like a straight wire, the division depends on the ratio of the resistor "above" the transistor to the portion of the pot which is "above" the wiper.  (Ignoring the cap...) When that part "above" the wiper goes to 0, the output is 0V.  The output can swing from top to bottom of the battery, a (almost) full 9V P2P. 

With a resistor between the wiper and ground that path never reaches 0 Ohms, which stops the whole thing swinging all the way to 0V, the full P2P swing is smaller.