Digitech Hot-Head

[Peter Snowberg]

I recently picked up a Digitech HotHead. I bought it for the price without hearing it. Upon first glance, the circuit appears to be a shunt style clipper with single gyrator based high and low tone controls. It also has an amp simulator output in addition to the normal output.

Very interesting construction.

The case is like a hybrid of a Boss pedal with a DOD pedal with every step taken to reduce manufacturing costs of the whole assembly. I don't know the case alloy, but it almost appears to be zinc?? The only off-board wiring is the 9V battery clip. Everything else is board mounted to a single PCB, including the pots (with long shafts), DC jack, signal jacks, and stompswitch which in this case is a little square micro-pushbutton switch. The actual switching appears to be the standard JFET/4007 flip-flop setup.

The chips, transistors, ceramic caps, and resistors are all SMD. There are also a bunch of through hole electrolytics and film caps.

In my quick low-volume junk amp setting test, it sounds decent, but the amp sim I found to be useless because it's not the response of any amp that I would want to simulate.

Does anybody have a schematic for this beast? Thanks!