Perseus Dio

The Catalinbread Perseus DIO is an all-analog sub-octave synth fuzz with independent control over three voices. Down 1 and Down 2 set the volume of one-octave-down and two-octave-down square wave signals respectively, while Dry controls a boosted version of your clean signal. Each octave voice gets its own second-order low-pass filter (Filter 1 sweeps ~280Hz–7kHz, Filter 2 sweeps ~140Hz–7kHz), letting you sculpt each octave independently.

The result ranges from thick sub-bass rumble to squealing 8-bit Nintendo tones depending on filter and blend settings. Unlike the original Perseus which had a single Blend/Cut control, the DIO's five-knob layout provides far more granular sound shaping. Runs on 9–18V DC at just 6mA.

Excels at synth-bass lines, experimental textures, and adding massive low-end weight to single-note riffs. The dual filters are the key—they transform raw square waves into something musical rather than just noisy.