Ensoniq Sq-R

Back in the early '90s, this rackmount gem brought Ensoniq's clever Transwave technology to a compact 1U format, letting you morph between complex waves for sounds that evolve in ways static samples just can't match.

At its core, it packs 21 voices of polyphony across 24 multitimbral parts, with each patch built from three sample-based oscillators drawing from 121 waves including acoustic samples, single-cycle synth shapes, and those signature Transwaves for harmonic depth. Dual multimode digital filters—mostly 2-3 pole lowpass sharing poles—pair with three 4-stage envelopes and a single LFO offering triangle, sine, saw, and square shapes, all routed through a versatile mod matrix responsive to velocity, monophonic aftertouch, mod wheel, and more. A 24-bit stereo effects processor delivers reverb, chorus, flange, delay, distortion, rotating speaker, compression, and wah, fully modulatable. Controls live on a straightforward front panel with dedicated buttons for banks, editing, and performance tweaks, plus a 3.5-inch floppy drive, PCMCIA slot for extra RAM/ROM cards (up to 160 more patches), and MIDI In/Out/Thru. Outputs include dual 1/4-inch TRS mains and a headphone jack, all in a slim 1.75 x 10.75-inch depth chassis that slides easily into any rig.

Players have long praised its rich, playable pads and realistic pianos that avoid voice stealing, plus the FX shine for instant polish—though some note the filters lack resonance, pushing creative routing instead. It's a vintage workhorse that still surprises in modern setups.