Fireman is a two-channel distortion pedal built around a modern brown-sound voicing. Each channel has its own Gain and Volume knob, so a rhythm level and a solo level can be set independently and switched with the 1/2 footswitch. A separate ON footswitch engages or bypasses the effect.

Tone shaping is shared between the channels through Bass, Treble, Presence and Tight controls. Tight reduces low-frequency content when turned down, which keeps heavily driven riffs focused. A toggle switch selects true bypass or buffered bypass, and a second toggle runs the circuit at 9V or at 18V internally, which gives a wider dynamic range.

The pedal has a mono input and output on the side jacks. An EXT. SW jack accepts a TRS dual footswitch that takes over the functions of the two on-board footswitches. Power comes from a 9V DC negative-tip adapter, and the manual is available in English and Japanese.