Empirical Labs EL-P Pump Vertical — a single-channel 500 series VCA compressor with a vertical faceplate, featuring 8 compression ratios and the unique AtMod function. PUMP is aimed at engineers looking for a compressor sharing DNA with the legendary Distressor, in a more accessible single-slot 500 series format. The module draws on the heritage of the Distressor, Arousor, and Mike-E, offering germanium-diode-based saturation and an attack-envelope shaping feature previously available only in the Arousor plugin. Preserving Transients Without Sacrificing Compression Density The usual trade-off with aggressive compression is losing an instrument's attack — a hard-squeezed snare or bass loses its initial click or thump, even if the rest of the signal sounds dense and controlled. AtMod (Attack Modification) solves this by slowing the initial slope of the attack envelope, letting more transient content back into the signal without giving up the intended compression level. That lets an engineer get a heavily compressed snare that still has a clear stick attack, or a thick bass that keeps its finger pluck intact. Eight Compression Characters in One Module Working across different sources — vocals, bass guitar, drums — a single fixed compression ratio rarely fits everything, and switching between separate processors slows a session down. PUMP offers eight selectable compression ratios from 2:1 to 20:1, each with its own unique curve, allowing a gentle touch for vocals or an aggressive squeeze for drums without leaving a single module. A switchable high-pass filter on the detector prevents low frequencies from unnecessarily driving compression. KEY FEATURES Single-channel VCA compressor in 500 series format, single slot Vertical faceplate orientation 8 selectable compression ratios: 2:1, 3:1, 4:1, 6:1, 8:1, 10:1, 12:1, 20:1 AtMod (Attack Modification) function to preserve transients under heavy compression Digitally-stepped Attack and Release knobs for precise, repeatable recall Opto-coupler-style Release option (auto-release) Switchable 70Hz detector high-pass filter Germanium-diode-based saturation, drawn from the Mike-E Full gain reduction metering and clip (BAD) indicator TECHNICAL SPECIFICATIONS Type: VCA compressor, 500 series format, single slot Faceplate orientation: vertical Frequency response: 5Hz - 175kHz (-3dB points) Dynamic range: 125dB (from maximum output at 0.5% THD to minimum output) Self-noise (Output at 0): typically -101dBu Distortion: 0.0035% to 15% at 1kHz, depending on mode and settings Maximum input level before hard clipping: +22dBm (Line In mode) Compression ratios: 2:1, 3:1, 4:1, 6:1, 8:1, 10:1, 12:1, 20:1 Detector filter: switchable, 70Hz