Korg EX-800 (1984)

An 8-voice programmable analog polyphonic synthesizer module released in 1984, designed as a desktop sound source for MIDI-equipped keyboards.

Overview

The Korg EX-800 is an analog synthesizer module released in 1984, built as a rackmount-compatible sound source for any MIDI-equipped synthesizer. It shares its sound engine with the Korg Poly-800 and is often described as the desktop or module version of that keyboard. The unit delivers 8-voice polyphony with a classic analog architecture, featuring two summable waveforms per oscillator—saw and square—with 8 oscillators (or 4 in dual mode). Despite its compact form, it’s known for producing lush pads and rich textures. It connects via MIDI and responds to note on/off messages, though it does not respond to sustain pedal input.

Specifications

Polyphony	8 voices
Function	Works as a sound source for any MIDI-equipped synthesizer
Oscillators	2 summable waveforms (saw, square) plus 4 oscillators
Filter	Single filter with resonance
MIDI Implementation	Responds to note on, note off
Power Supply	9V DC, 0.3 Amp, centre-negative
Dimensions	Width: 404 mm, Depth: not fully specified
Year Released	1984
Original Price	$795 (list price)

Design

The EX-800 uses a classic analog sound engine with a paraphonic voice architecture—only one amplitude generator controls all four notes in dual mode, and all oscillators pass through a single filter. The unit features a Moog Slayer modification that has become popular among users to enhance its filter response. It lacks sustain pedal functionality in its stock MIDI implementation.

Context

The EX-800 was designed as a module version of the Korg Poly-800, allowing users to expand their MIDI setup with the same analog tone in a compact, keyboardless format. It served as a cost-effective way to integrate the Poly-800’s sound into larger systems.

Market

In 2017, units sold between $249 and $366. By 2018, a modified EX-800 with the Moog Slayer filter mod listed for $350, while another unit in excellent condition was priced at $950. Common upgrades include filter modifications and SD adaptations for expanded patch storage.