ARP Soloist (1970–1972)

It starts with a flick of the thumb - 18 preset sounds, zero patch cables, and a keyboard that responds to how hard you press, not just which key.

Overview

You don't program the ARP Soloist. You command it. One moment you're playing a flute patch, the next you're snarling through a fuzz guitar tone - all with a single flip of a toggle switch. ARP released the Soloist in 1970, and it wasn't trying to compete with the modular beasts of the era like the Moog or its own 2500. It was built for organ players who needed a compact, expressive lead voice they could set on top of their Hammond and use immediately. No patch cords, no deep editing, no tuning marathons. Just 18 preset sounds, a pressure-sensitive keyboard, and a control scheme that put performance ahead of programming.

The design idea was radical for its time: make synthesis accessible. Other synths demanded technical fluency. The Soloist treated presets as instruments. Each toggle switch called up a complete patch - oscillator, filter, envelope settings, and effects - all hardwired and instantly available. The lack of programmability might sound limiting now, but in 1970, switching sounds on the fly without repatching was revolutionary. This wasn't a synth for tweakers. It was for gigging keyboardists who needed reliability and speed.

Under the hood, the Soloist was monophonic, with a single VCO generating pulse and sawtooth waveforms, routed through a 24 dB/octave low-pass filter and a VCA. What set it apart was the touch-sensitive keyboard. Long before aftertouch became standard, the Soloist used a pressure bar under the keys to detect how hard a note was pressed. That pressure could modulate pitch, filter brilliance, vibrato, volume, and portamento - collectively marketed as "growl," "wow," and "brilliance." A player could start a note softly and then push into it to add vibrato or a pitch bend, all with one hand. For organists used to Leslie speed controls and drawbars, this was intuitive and expressive.

The Soloist had its limits. It never achieved the same reputation as ARP's later Odyssey or 2600. Its presets were fixed, its tuning was notoriously unstable, and its build quality left something to be desired. Documentation shows that musicians like Donald Fagen of Steely Dan found the Soloist frustrating in live settings because of constant detuning. It was a transitional instrument - ambitious and innovative, but flawed. ARP knew it. By 1972, they'd already begun work on its successor, the Pro Soloist, which would fix many of these issues and become the definitive version of the concept.

Specifications

Manufacturer	ARP Instruments, Inc.
Production Years	1970–1972
Original Price	$1,195 (estimated)
Synthesizer Type	Monophonic analog preset synthesizer
Keyboard	37 keys (3 octaves)
Aftertouch	Pressure-sensitive touch bar under keys
Oscillators	1 VCO (pulse, sawtooth)
Filter	24 dB/octave low-pass (ARP4012)
Filter Modulation	Brilliance (filter cutoff)
Amplifier	Voltage-controlled amplifier (VCA)
Envelope Generators	Single contour generator (attack, decay)
LFO	Internal vibrato and wow (portamento) modulation
Preset Voices	18
Effects	Vibrato, portamento ("wow"), growl (pitch modulation)
Controls	Toggle switches for presets, octave shift, expression effects
Outputs	1 x 1/4" output
Power	External power supply (±15 VDC)
Weight	Approx. 18.5 lbs (8.4 kg)
Dimensions	34" x 10" x 4" (86 x 25 x 10 cm)
Finish	Black textured vinyl, silver control panel

Key Features

The Preset Revolution

Before the Soloist, changing sounds on a synth usually meant repatching cables or manually adjusting multiple knobs, a slow, error-prone process on stage. The Soloist got around that by hardwiring 18 complete patches into the circuitry. Each preset, with names like "Flute," "Bassoon," "Fuzz Guitar," and "Brass," was a full signal path with oscillator settings, filter response, and envelope behavior baked in. ARP wasn't selling a modular tool, but a set of ready-to-play instruments. For touring musicians, this meant no soundcheck tweaking, no forgotten knob positions, no tuning drift mid-song. You flipped a switch and played. That made it a favorite among organists and session players who needed reliable, expressive lead tones without the synth-geek overhead.

Touch-Sensitive Expression

The Soloist's keyboard wasn't just velocity-sensitive. It responded to aftertouch, a feature almost unheard of in 1970. The pressure bar under the keys detected how hard a note was held and routed that data to multiple parameters at once. Push harder, and you could add vibrato, brighten the filter, bend the pitch, or swell the volume, all in real time. ARP called these "expression effects," and they were controlled via dedicated switches that let players assign which parameters responded to pressure. That let the Soloist mimic the breath control of a wind player or the attack of a plucked string. It was a precursor to modern MIDI aftertouch, but with a tactile, analog feel.

Organ-Top Form Factor

The Soloist was designed to sit on top of a Hammond or electric piano, not on its own stand. Its low-profile chassis, 34 inches wide and just 4 inches tall, slid neatly over the back of a B3 or a Rhodes. It even came with a built-in music stand, handy for gigging keyboardists who needed to read charts while playing. This was no accident. ARP targeted organ players specifically, offering a way to expand their sound without abandoning their main instrument. The control layout, with toggle switches under the left hand, mirrored the thumb-operated drawbar controls on a Hammond, so it felt familiar.

Historical Context

The ARP Soloist emerged at a time when synthesizers were still seen as laboratory curiosities or avant-garde noise boxes. The Moog modular systems were dominant, but they were expensive, temperamental, and required technical expertise to operate. ARP's founder, Alan R. Pearlman, had set out to build more stable, musician-friendly instruments, starting with the 2500. The Soloist had a different mission: not to push the boundaries of synthesis, but to bring it to the working musician.

In 1970, most rock and pop keyboardists were organ players. They didn't want a modular synth. They wanted a way to get flute or brass sounds quickly and reliably. The Soloist answered that need. It wasn't programmable, but it didn't need to be. Its presets were designed to emulate real instruments, and while they were crude by modern standards, they were convincing in a mix. The synth found early adopters in progressive and jazz-rock circles, where players like Billy Preston and Herbie Hancock began incorporating its sounds into live sets.

The Soloist's legacy is overshadowed by its successor. The Pro Soloist, released in 1972, fixed many of its tuning and reliability issues and expanded the preset count to 30. The original Soloist became a footnote, a prototype of a better idea. The Soloist Mk II, an intermediate redesign with digital tuning, never made it to market. ARP simply leapfrogged to the Pro Soloist, which became the definitive version. Still, the original Soloist was the first to prove that preset synths could be expressive and practical, paving the way for instruments like the Yamaha CS-80 and the Roland Jupiter-8.

Collectibility & Value

The ARP Soloist is a rare bird. Few were made, and fewer survived. Its tuning instability and fragile internal components mean most units today require extensive restoration. Service technicians observe that the original VCOs and power supplies are prone to drift and failure, and the pressure-sensitive keyboard mechanism often degrades over time. Capacitors dry out, switches oxidize, and the toggle selectors, used constantly during performances, can become flaky.

Collectors note that original Soloists in working condition are scarce, and prices reflect that. As of 2025, a fully restored Soloist can command between $2,500 and $5,000, depending on provenance and condition. Unrestored units sell for $800 to $1,500, but buyers should assume several hundred dollars in repair costs. Finding one is only half the problem. Keeping it in tune is the other half. Unlike later ARPs, the Soloist lacks the temperature-stabilized oscillators of the Pro Soloist, so even a well-recapped unit may drift during extended use.

For players seeking the Soloist's sound, a more practical route is the Pro Soloist or a software recreation like Cherry Audio's Pro Soloist or Wrongtools' sample library. These get close to the sound without the maintenance headaches. Purists prefer the tactile response of the original pressure bar and the gritty, imperfect tone of 1970s analog circuitry. The Soloist isn't the easiest synth to own.