The Cholla (cho-ya) boost is a single control overdrive boost.
The control makes a rustling sound as it's adjusted and only when it's being adjusted. This is by design as the control adjusted multiple circuit parameters simultaneously. There is nothing wrong with the control pot.
It can go from low gain overdrive at minimum to very overdriven with pushed
mids at maximum. Think of your favorite vintage Class A tube amp on 10... yeah that's the sound!
The Cholla has 27dB of boost available to drive edge of breakup amps or other drive type pedals into sweet signing sustain.
As the control of the Cholla is increased the EQ of the circuit is altered from wider range at minimum to pushed mids with more focus at maximum.
Keeping the lows intact and tight while allowing the harmonics to fill in the highs.
It's a great circuit to put in front of your vintage amplifier to get a sweet fat breakup out of it.
Great for soloing or making up for low level vintage pickups.