At the beginning of the 70s, analog synthesizers were just making their way into the hands of working musicians, and their operation was still a mystery to most folks outside of a college music lab. To avert potential user intimidation and bring synthesis to the masses, manufacturers introduced simple monophonic preset synths that were intended to sit atop an organ. ARP led the charge in 1970 with the Soloist, the first commercial preset synthesizer, featuring 18 presets and basic controls.

In 1972, ARP followed it up with the Pro Soloist, updating the analog preset control with revolutionary digital read-only memory chips (which improved tuning stability) and expanding the preset selection to 30. Most impressive was the introduction of an innovative “touch sensor” keyboard (now commonly known as aftertouch), where pressing harder after playing a note introduces changes to the sound, allowing highly expressive playing. Specifically, the Pro Soloist’s touch sensor controls enabled pitch bend, wow, growl, brilliance, volume, and vibrato. This was heady stuff in the early 70s, and the Pro Soloist proved popular with musicians for its ability to rapidly emulate lead instrument sounds such as horns, strings, woodwinds, and more.

Despite its association with progressive rock, the Pro Soloist was popular with acts as varied as Tangerine Dream, Gary Numan, Kansas, Herbie Hancock, Patrick Moraz, Styx, John Entwistle, Parliament, Billy Preston, Vangelis, David Bowie, Brian Wilson, the Ohio Players, Chick Corea, Prince, and Josef Zawinul. Most notable was Tony Banks of Genesis, for whom the Pro Soloist was his first synthesizer. The track “The Cinema Show” on the 1973 album Selling England by the Pound showcases many of the Pro Soloist’s presets building up to his epic solo featuring the “Fuzz Guitar 1” preset.

Reintroducing the Pro Soloist, Unbound!

Cherry Audio has received frequent requests to reproduce this oft-forgotten gem — one of those came from frequent collaborator Mark Barton (GX-80, Novachord + Solovox, Miniverse, and others). He has programmed an incredibly authentic reproduction of the analog signal path and original presets, and together we have substantially expanded the Pro Soloist’s capabilities. Cherry Audio has added a dual-layer voicing architecture, with 16 polyphonic voices per layer, that enables two different presets simultaneously, with independent panning for rich stereo timbres and complex, layered sounds. Pro Soloist also supports a split keyboard mode and an option to simulate polyphonic aftertouch with a monophonic aftertouch controller for more expressive performance possibilities beyond the standard touch sensor effects.

With its distinctive three-panel interface, this Pro Soloist is far more than a preset synth. In Performance mode, each original paddle preset has been precisely recreated with MIDI-mappable switches. In Edit mode, we’ve exposed all of its unique analog synthesis architecture parameters, most notably, the fully-variable, five parallel bandpass filter “Resonator Bank” - the key to the Pro Soloist’s realistic acoustic orchestra timbres. Additionally, we’ve revealed the LFO and ADSR/AR envelopes used to create the presets, and elevated the sound design and performance possibilities with a "Super Wave" oscillator and a powerful six-slot modulation matrix. The Arp/FX mode rounds it out with a syncable arpeggiator and a dozen studio-quality effects for distortion, phaser, flanger/chorus, echo, and reverb.

In short, Cherry Audio has elevated this bare-bones monophonic lead synth into a massive, polyphonic powerhouse beyond anything imagined 50 years ago, and ideal for today's music production environments.

To get users up and running with Pro Soloist, Cherry Audio and Tim Shoebridge have again teamed up to create introductory tutorial videos walking users through the history and features of this iconic virtual synthesizer.