Cherry Audio Revives the Gleeman Pentaphonic, a Synth Built Fewer Than 70 Times

Cherry Audio has released a software recreation of the Gleeman Pentaphonic, the analogue polysynth designed by brothers Bob and Al Gleeman in 1981 and estimated to have been manufactured fewer than 70 times. The plugin costs $59. Second-hand hardware has been known to sell for as much as $5,000, which is the usual reason instruments this scarce end up as emulations.

The original Pentaphonic arrived in a black chassis with a handle and built-in speaker, a portable five-voice synth with fifteen DCOs running through Curtis CEM 3320 4-pole filters, the same chip used in the Prophet 10 and Oberheim OB-8. Its successor, the Pentaphonic Clear, went further: transparent acrylic housing, plexiglass knobs, internal lighting over the circuitry. The design did not save the company. Production wound down as digital instruments took hold, though the Pentaphonic found users as far apart as Depeche Mode, Oscar Peterson, REM and The Band.

Cherry Audio’s version is modelled partly on an unreleased 1983 successor the Gleemans designed but never built, which was intended to have eight voices, a 61-key keyboard, expanded sequencing and MIDI. The plugin offers mono and poly modes with up to 16 voices, three oscillators per voice based on the original DCOs, PWM on each oscillator, oscillator sync, a noise generator, an extra LFO, a 2-pole filter mode, velocity sensitivity and channel and poly aftertouch. There is also a tempo-synced arpeggiator, a 16×4 polyphonic step sequencer, an additional per-layer sequencer called the Parameter Animator, 22 effects and three interface themes drawn from the synth’s cosmetic eras.

What makes this more than a catalogue entry is the 1983 design at its centre. The Pentaphonic has been preserved as a rare object; the version that might have kept the Gleemans in business was never heard at all.