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Empirical Labs Pump 500-Series Compressor  From Empirical Labs

500-Series tribute to the famed ELI Distressor. Compressor, Limiter and Saturator, with AtMod "Attack Modification".

Empirical Labs


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Manufacturer's Description from Empirical Labs

The PUMP is a 500-series module compressor that has taken the DNA of the Distressor and distilled it into a single 500 space package at an affordable price. It also borrows features from some other ELI products, like a germanium diode-based saturation circuit similar to the one in the Mike-E and the attack envelope shaping AtMod from the Arousor plugin (that’s right, we took a software feature and turned it into hardware!).

Note: Available in both Vertical and Horizontal-labeled versions.


  • VCA style compressor circuit
  • 8 ratios from 2:1 to 20:1
  • Stepped attack and release knobs for easy recall
  • Attack time ranging from 200µs to 40ms
  • Release time ranging from 50ms to 500ms
  • Soft-clipping saturation
  • AtMod (Attack Modification)
  • Switchable Detector HP
Empirical Labs

About Manufacturer

Empirical Labs Inc. (ELI), designs and produces professional audio equipment and software. This includes equipment used in recording studios, live sound, broadcast studios and other audio production facilities etc. We also make software for digital signal processors. Most of you are here because you have heard about or used our Distressor. This product, which is our first hardware product, was designed in 1994, tested and revised for several years, and released in early 1996. The Distressor is the first in a series of audio products from ELI that will offer original features, ease of use, long product life, and a very musical audio path. Empirical Labs was started in 1988 and functioned mainly as a recording studio and electronics consulting firm. The founder, Dave Derr, was also employed at the time by Eventide as an audio engineer. Dave was part of the core design team for the H3000, H3500, and DSP4000. His experience at Eventide proved valuable for his later work. While working alongside Ken Bogdanowicz and Bob Belcher (both now at Wave Mechanics), Dave was exposed to great engineering and the modern world of digital signal processing (DSP).