Electrix Pro Filter Factory

Back in the late '90s, this rack unit became a go-to for artists like U2 and the Chemical Brothers, who loved how it turned static mixes into throbbing, alive soundscapes with its analog-style filtering magic.

It's a 2U stereo rackmount processor with a signal path that kicks off with adjustable distortion via the Buzz knob for grit, followed by a Trim control to tame levels before hitting the core filter block—a 2-pole 12dB/octave design (digital implementation) that spans 20Hz to 20kHz, self-oscillates at max resonance, and switches between lowpass, highpass, bandpass, and notch modes with a single button and status LEDs. Big knobs handle Frequency, Resonance, LFO Depth, Speed (with tap-tempo), and waveform selection from four shapes, plus Single Shot mode for triggered sweeps that repeat 1-6 times. Momentary buttons let you punch in effects or reset the LFO live, while CV/Gate inputs, footswitch jack, balanced TRS and RCA I/O (with switchable phono preamp for turntables), and MIDI In enable sequencing, automation, and recall of all settings—no internal patches, but everything sysex-dumps to your setup. Stereo operation shines, but flip to 4-pole mono for steeper 24dB/oct cuts.

Users still hunt these down on the used market for their smooth, musical resonance and unique distortion-filter combo that plugins struggle to match—super fun for sweeps on drums, synths, or full mixes, though watch the self-oscillation if levels run hot.