Alesis QuadraSynth Plus
The QuadraSynth Plus brought 64-voice polyphony and expressive S&S synthesis to 1994 — rich layered sounds, excellent piano samples, and a deep modulation system for its era.
Overview
The QuadraSynth Plus is Alesis’s flagship synthesizer from the mid-90s, and it punched above its class in several respects. Most notably: 64-voice polyphony at a time when most competitors offered 16 or 32. That headroom makes a real difference in complex, layered patches where voice-stealing on lesser instruments becomes audible.
The synthesis architecture is S&S (Sample and Synthesis) — ROM-based PCM waveforms fed through a digital filter with resonance, four-stage envelopes, and a flexible modulation matrix. Each program can layer up to four elements, making deep, evolving sound design possible within the engine. The QuadraSynth Plus adds expanded wave ROM over the base QuadraSynth, with better piano samples that are still competitive today for a vintage digital piano sound.
Alesis also gave the QS Plus their ADAT-era build quality — solid, heavy, reliable. The 76-key semi-weighted keyboard is pleasant to play, and the interface, while dense, rewards time spent with it.