SynthsEnsoniq ⇝ Ensoniq SQ-1

Ensoniq SQ-1 PlusEnsoniq SQ-1 Plus BackEnsoniq SQ-1 Plus Left SideEnsoniq SQ-1 Sound ControlsEnsoniq SQ-1 Sequencer ControlsEnsoniq SQ-1 Plus Main Board

The Ensoniq SQ-1 is a digital synthesizer based on ROM waveforms (a ROMpler). It is patch-compatible with the Ensoniq SQ-2 (the 76-key version with the same engine) and the Ensoniq KS-32. It is also available in rackmount form as the SQ-R.

21-note and 32-note-polyphonic versions of the SQ-1 exist. The models are SQ-1, SQ-1 Plus, and SQ-1 Plus 32-voice. The plus versions have improved piano sounds.

It contains a set of 9 transwaves that can be used for wave sequencing. Here is the transwave list:

Common Repairs

The CR2032 memory backup battery is soldered to the main board. When it dies, a battery holder should be installed in its place.

The front panel buttons are table-shaped and rest on a plastic frame. The legs can become bent or broken, causing buttons to be permanently pushed in. They are not difficult to replace if you can find spares.

The 1/4" audio connectors are plastic and not flush with the case. They can break and will need to be replaced with new ones, but they are fairly standard and a simple soldering job to replace.

Broken keys can be challenging because you have to completely disassemble the synthesizer to remove the keyboard, but once you've removed so many screws that your hand hurts, replacing a key is simple. The key return springs have a fair amount of tension, and you will need pliers to reattach them.

Internally, the SQ-1 has 3 circuit boards - a power supply board, the main board which is managed by a Motorola 68000 CPU, and the front panel display/button board.


To our knowledge there wasn't a copy of the SQ-1 Plus / SQ-2 manual available in PDF form, so we scanned our copy. It's available below.


Year Released: 1991

MSRP: $1595

Keyboard: 61 keys with velocity

Polyphony: 21 notes

Multitimbral: 24 parts

Preset Patches: 100

User Patches: 80

ROM: 3MB (167 16-bit waveforms including 1 MB piano)

Dimensions: 1026 mm x 340 mm x 130 mm

Weight: 11.3 kg

Latest OS Version: 1.11

Latest OS Version For SQ-1 32: 2.03

Latest OS Version For SQ-1+: 1.15

User Demo Videos


(1 votes)

Sound Samples

WAV samples are available on

File Downloads

Ensoniq SQ-1 Plus and SQ-2 Manual

KSEdit for Ensoniq SQ Synths (Windows Freeware Works with Ensoniq KS-32, SQ-1, SQ-2, and SQ-R)

Items for Sale on Reverb

Ensoniq SQ-1 Keyboard - Panasonic REPLACEMENT BATTERY ONLY! - 3 Solder ProngsEnsoniq SQ-1 Keyboard - Panasonic REPLACEMENT BATTERY ONLY! - 3 Solder Prongs ($13.49)

Ensoniq SQ-1 Keyboard - Panasonic REPLACEMENT BATTERY ONLY! - 2 Solder ProngsEnsoniq SQ-1 Keyboard - Panasonic REPLACEMENT BATTERY ONLY! - 2 Solder Prongs ($13.49)

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Ensoniq SQ1 Plus 1990Ensoniq SQ1 Plus 1990 ($450)

1991 Ensoniq SQ1 Plus Synthesizer1991 Ensoniq SQ1 Plus Synthesizer ($400)