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

21-note and 32-note-polyphonic versions of the SQ-1 exist.

Latest OS Version: 1.11

Latest OS Version For SQ-1 32: 2.03

Latest OS Version For SQ-1+: 1.15

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

We currently have an SQ-1 Plus 32-voice for sale on eBay.

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.

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

User Demo Videos

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)