The Supra uses two stages of distortion and the first is modified for a good overdrive style circuit with improved bass and wider gain range. In overdrive circuit style, there is a clean signal component at all times mixing inphase with the distortion. This becomes the primary distortion signal, and the added Mix control adds in the second stage of distortion, reversed in polarity (antiphase), subtracting from the lower level of distortion, so that the differences between the distortions can be emphasized and the common signal can be eliminated.

As an overdrive, the gain goes down enough to use as a dirty boost. The Mix control can be used to make the overdrive grittier and gated. At higher gains and Mix settings there are metal sounds and turbulent, dynamically responsive synth-like tones. The original tone control circuit comes into its own with this mod.

DOD's FX-55C utitilized an improved enclosure compared to their older style, JRC4560D op-amps, and more circuitry including a better silent switching bypass system. This mod improves that bypass by increasing input impedance, and also a new "bleed reducer" circuit for full transparency. This modification does not produce any of the original sounds of the pedal and can not be applied to the "55" or "55B" versions of the Supra.

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Suprazombie's method of distortion variation is to use mixing, including antiphase mixing. Imagine being able to control how distorted or fuzzy the sound is seperate of gain and sustain. Some of the results sound "blended" while other mixes produce a new sound with little hint of its constituent parts.

The example to the right shows graphically how this works. "A" is the positive portion of a distorted wave. "B" is more distorted (more gain) and inverted (upside down). "C" shows how these add together, forming a harsher, more complex waveform. This still only hints at the sonic possibilities. See also Intellectual Property Statement.