The Ensoniq SQ-1 is a digital synthesizer and music workstation released in 1990 by the American instrument manufacturer Ensoniq. It was designed as an affordable, all-in-one "Personal Music Studio" combining ROM-based sample synthesis, a multi-track sequencer, and digital effects. [1, 2, 3]Key Specifications and Features

• Keyboard: 61-note velocity-sensitive keyboard (lacks aftertouch on the base model). [1]
• Polyphony: 21 voices (later expanded to 32 voices in the SQ-1 Plus and subsequent variants). [1, 2]
• Synthesis Engine: ROMpler architecture using 16-bit PCM sample waveforms and Transwaves (wavetable-like moving waves). Supports up to 3 oscillators (voices) per sound patch. [1, 2, 3]
• Filters: Dual non-resonant serial digital filters. [1, 2]
• Sound Memory: 100 ROM presets and 80 user RAM patches (plus card slot expansion). [1, 2]
• Sequencer: Built-in 16-track sequencer (8 sequence/track components, 8 song tracks) with a base memory of 9,000 notes, expandable. [1]
• Effects: Integrated 24-bit digital multi-effects processor featuring 13 algorithms (such as reverb, chorus, and delay) with dynamic modulation. [1, 2]
• Connections: Stereo audio outputs, headphone jack, footswitch inputs, and MIDI In, Out, and Thru
  
  Pretty good conditions, ships with soft case