I just finished my overdrive pedal 🙂 It can be powered off a 9v battery or wall adapter. The control across the top from left to right are hotness, tone, gain. The bottom two knobs are variac and volume.
The “Hotness” control allows fine tuning of the internal amplifier to accommodate different guitar pickups. Basically it compensates for different pickups to allow for a nice variety of tone.
Tone and gain should be pretty easy to understand for most.
Variac allows me to adjust the input voltage powering the logic IC used in this overdrive pedal. I can starve the input voltage to give it some subtle changes in tone.
And the volume… lets me adjust the volume 🙂
Anyway, I don’t have labels for it and am considering a name for it. Perhaps… Thundersqueak 🙂