Back in 1971, only about 35 of these gray-panel originals ever saw the light of day, making them one of the rarest beasts in synth history—now faithfully recreated with modern tweaks for today's players.
This semi-modular powerhouse packs three VCOs with sawtooth, triangle, sine, and PWM waveforms, plus sync on oscillators two and three, all feeding into a resonant low-pass filter with switchable 4012 or 4072 modes for that classic ARP bite. You've got dual envelopes—ADSR and AR—two LFOs that can modulate VCOs or run solo, a ring modulator, sample & hold, envelope follower, and voltage processor, all tied together with 93 patch points and 78 faders for hands-on signal routing. The real standout is the mixable mechanical spring reverb tank, delivering authentic drippy ambiance, alongside duophonic mode for two-note harmonies, stereo VCA with panorama, and MIDI via USB or DIN for easy integration. Sized at 95HP for Eurorack or desktop/rackmount setups, it includes mono audio in/out, pedal jacks for portamento and interval latch, and even DIP switches for MIDI channel tweaks.
Players love how it nails the ARP 2600 vibe with upgraded stability and that genuine spring reverb—praised for fat basses, leads, and experimental patches—though some note the fader workflow takes getting used to if you're knob-centric. It's a steal for diving into semi-modular without breaking the bank.