Back in 1974, this synth marked ARP's bold step away from rigid presets, borrowing the exact 4027-1 VCO from the legendary 2600 and a fat 4034 Moog ladder filter clone for sounds that punched above its single-oscillator weight.
Its compact metal chassis with maple ends measures about 33 inches long, housing a 37-key (three-octave) velocity-insensitive keyboard without aftertouch. A single voltage-controlled oscillator delivers sawtooth, square, pulse (with width control), plus sub-octaves down to 16T, noise, and even fuzz—all mixable for rich timbres. The low-pass filter offers cutoff and resonance sliders, paired with a versatile ADSR envelope, while the LFO modulates cutoff or VCA with delay. Effects include repeat, delayed vibrato, portamento, pitch bend, and presets like flute or strings, all tweakable in manual mode from the front-panel sliders.
Players like Herbie Hancock and Philip Glass put it on the map for its programmable flexibility, bridging preset portability and raw synthesis—though some note its monophonic limit and basic envelope as trade-offs for that era's road-ready vibe.
