PUMP, a 500 series rack mount compressor from Empirical Labs, was first imagined in 2014. This module boasts features and performance similar to those of renowned ELI processors like Distressor, Arousor, and Mike-E. With its impressive heritage, PUMP is poised to become the "go-to" processor for creative audio pros who value no-compromise performance, quality, and value.
PUMP's controls for Input Level include a clip (BAD) indicator, and users can choose from 8 selectable compression ratios ranging from 2:1 to 20:1. Each ratio has a unique curve. Users can make precise Attack and Release selections with independent digitally-stepped knobs, including a soft Opto-Coupler style Release. PUMP also features a switchable 70Hz High Pass Filter, comprehensive Gain Reduction metering, and Attack Modification (AtMod) to slow the initial onset of the attack envelope, preserving more transient content for greater overall impact. Users can select Bypass to go dry.
One of PUMP's most unique features is AtMod, a feature first seen in the Arousor plug-in and never before found in a hardware compressor. AtMod lets users slow down the initial slope of the attack envelope, allowing more of the transient back into the track. This feature is useful for adding snap to snare tracks or thump to electric bass tracks without losing the desired amount of compression.
PUMP's specifications include a frequency response of 5 Hz to 175 kHz (-3dB points), dynamic range of 125 dB from maximum output (.5%THD soft clipping) to minimum output, and a noise floor of typically -101dBu with Output on 0. Distortion ranges from .0035% to 15% at 1KHz, depending on mode and settings. PUMP can handle a maximum input before hard clipping of +22dBm in "Line In" mode and a maximum output (Mix at 0) of +28.5dBm. In Instrument In Mode, the impedance is 120k Ohm, and the output impedance is less than 75 ohms. In balanced Line in mode, the input impedance is 20K. Compressor Time Constants include Attack: 200µs to 40ms and Release: 50ms to 500ms, plus Opto setting. PUMP is stereo linkable for stereo tracks and includes a detector HP Filter, switchable and fixed at 70Hz. Additionally, PUMP features a Saturation Soft Clipper based on the same circuit found in the Mike-E CompSat section.
