E-mu ESI-4000

Back in 1997, this rackmount sampler doubled the polyphony of its predecessor, the ESI-32, jumping to a smooth 64 voices mono or 32 stereo, making it a studio workhorse for layering complex sounds without voice stealing.

It packs 4MB of sample RAM standard—expandable to 128MB via 72-pin SIMMs—for loading up to 999 samples into 256 presets, with zones freely split or layered across the keyboard. Stereo 16-bit sampling at 22.05kHz or 44.1kHz happens through rear RCA inputs (mic to line level), or digitally via S/PDIF on Turbo models at up to 48kHz. Per-voice synthesis shines with 64 digital 6-pole filters across 19 types—like Z-plane morphing, phasers, formants, and that classic 24dB/octave lowpass—plus AHDSR envelopes, a multi-wave LFO, and DSP tools for time stretch/compression, parametric EQ, and crossfade looping. The front panel features a 20x4 backlit LCD, data wheel, 10-key pad, cursor keys, and 10 trigger buttons for instant sample firing without a keyboard, alongside a 1.44MB floppy (or Zip on Turbo Zip) and SCSI for hard drives or CD-ROMs. Audio outs include 4x RCA (main L/R, sub L/R), headphone jack, and effects processing like reverb, delay, chorus, flange, plus distortion on Turbo.

Users have long praised its clean, high-quality sound and analogue-like filters that hold up in modern mixes, though the learning curve for the OS can take a day or two to master. It's a vintage gem that still delivers pro results on a budget.