The Ultimatum Distortion circuit is a tape saturation simulation circuit, and is housed in a standard SR&D rockmodule box, with only a few controls to adjust parameters. Of particular interest is the Series "R" knob, which adjusts the amount of resistance of the signal prior to the "growl" compression stage. There is also a buffer select switch, a buffer active indicator LED, a hardwire bypass switch, and a THD 1% threshold indicator LED. The "Growl" circuitry applies distortion to just the low end, ~ 100Hz down, as to simulate "Tape Head" distortion, which Tom loved so much. The exact nature of these modules is unknown, but the insides were described by one tech to look like a "birds nest" because of all the wiring. It's possible that Tom may have simply had the Ultimatum Footpedal rackmounted in a Rockmodule box, or they could be prototype units of a Rockmodule model. The effect of the Ultimatum Distortion is very subtle, but effective.