Up for sale, a 1980s Korg PolySix analog polyphonic synthesizer in excellent condition and in perfect working order, augmented with the complete KiwiTechnics KiwiSix upgrade kit and modification suite. First released in 1981, the PolySix is easily among the most important synths of its era, boasting “real” analog VCOs and a suite of onboard features including 6-voice polyphony, patch memory with a cassette port for patch backups, an arpeggiator and sequencer. KiwiTechnics’ KiwiSix upgrade dramatically increases the functionality of the unit, adding modern functionality and stability, and replacing potentially problematic components including the circuit board (very frequently battery damaged in original units) and power supply.

Thanks to the SSM2044 4-pole voltage-controlled filters, the PolySix has a warm, organic, almost brassy sound; more overtly gentle than a Juno-6, but big and bold for 6-voice unison leads. Standard controls include Tuning; Bend Intensity; VCO/VCF/VCA sculpting; EG Attack, Decay, Sustain, and Release; and a small suite of onboard effects including Chorus, Phaser, and Ensemble Intensity, all governed by a Speed/Intensity knob. The Ensemble effect utilizes a “bucket brigade” analog delay design, able to produce an almost Mellotron-esque thick and rich sound. The Arpeggiator is governed by an independent Speed/Intensity knob, with switchable parameters/arpeggio direction and breadth controls via a pair of three-way switches, and is able to “memorize” and sequence chords. The Programmer controls have been altered by the KiwiSix upgrade, switching from Tape management to MIDI functionality, but general sequencing remains largely the same with a range of selectable note durations and functionality like transposition and tempo adjustment.

The KiwiSix upgrade significantly expands overall functionality and mitigates several issues common to the PolySix, including replacing the original KLM-367 circuit board and power supply with modern voltage regulators, preventing overvoltage-related damage. Other features include:

• A storage upgrade to 512 tone slots, all able to be stored/edited, with 64 preloaded tones
• Sequencer expansion with 8 separate saveable/editable 124-max step sequences
• MIDI functionality, with the ability to independently set the MIDI I/O channels
• Arpeggiator and Sequencer MIDI output, and MIDI input control for the Sequencer
• Upgraded internal clock hardware, with both the Arp and Seq independently divided from the Master Clock, can optionally generate a MIDI clock
• Key Transposition range augmentation from 1 octave down to 2 octaves up
• Chord Mode, wherein any chord with up to 6 notes can be set and played from any ket
• Ferrite clamps for noise reduction
• Free system software updates via the KiwiTechnics website

Cosmetic wear is limited to some minor marks and scuffs, primarily on the wooden endcaps. The graphics are clean (including the new KiwiTechnics graphics), and all of the original knobs, buttons, and keycaps are present.

The KiwiSix user manual is included.