From the manufacturer’s website:
“The Deputy Marshal Captures the undeniable sound of British Plexi tube amps that defined the era of classic rock.
The “Gain”, “Tone” and “Volume” controls allow you to determine your distortion with precision.
The “BRIGHT / NORMAL” switch offers even more versatility with reinforced highs in one click.”
“The Rocker Box is an optical tremolo that gives you the tools to unearth rich, natural sounding tremolo effects.
Bias control adjusts the tonal complexion of the sound wave, offering everything from smooth and polished trem to the looser, non-symmetrical waveforms of vintage tube amps.
Depth and Speed controls give you the ability to further fine-tune the effect.”