Each position activates its own components rather than applying a mod to one base circuit. JHS measured nine vintage units, including component drift, and replicated each one. The list covers the 1977 OD-1, TS-808, TS-9, MSL, TS-10, Exar OD-1 and TS-7 hot mode.

Two modified versions complete the set: the Keeley Mod Plus and the JHS Strong Mod. The OD-1 mode ignores the Tone knob, inverts polarity and uses asymmetrical clipping. TS-7 gives the highest gain, while the TS-808 setting stays low gain with a strong midrange.

Volume, Drive and Tone apply to whichever mode is selected. The JHS Strong Mod setting is cleaner and more powerful than the stock voices, with steeper treble and bass roll-offs.