The Distressor EL8-S from Empirical Labs is a pair of professional compressors that feature a wide range of controls and feature set for studio or live applications.
 
The Distressor offers a warm, vintage sound by using a custom designed gain control circuit. All eight of the Distressor's curves are distinctive, from the 1:1 mode that simply warms up signal with low order harmonics without intentional compression, to the Nuke setting, a brick wall limiting curve that shines on live drum room mics. Some curves have different circuitry, and are effectively different compressors. The 10:1 Opto ratio uses separate detector circuitry to emulate the oldest light controlled devices, such as the LA-2A.

The Distressor features three modes that color the signal, even without compression. These extended audio modes were designed to allow emulation of some very old vintage compressors and limiters, and let the Distressor deliver a classic knee sound all its own by providing user programmable, warm harmonic distortion. In addition to the basic distortion mode, Distort 2 emphasizes tube-like 2nd order harmonics, while in the Distort 3 setting the distortion becomes dominated by 3rd harmonics more closely resembling tape. Two HP filters, with one in the audio path, one in the detector path, are also available to help with low frequencies that can cause pumping and breathing.

This stereo pair of Distressors are matched at the factory, and come with the cables you need to lock them together.
 
The Features
Classic Knee Sound  Improved noise specs and performance
Programmable Analog Distortion/Warmth  Three audio modes provide user programmable, warm harmonic distortion. Emphasized tubelike, 2nd harmonic in clean and Distort 2 mode. In Distort 3 mode, the distortion becomes dominated by 3rd harmonic, more similar to tape
Distortion Indicator Lights  A 1% LED and a Redline (3%) LED providing no hard clipping until a few dB past Redline
Advanced Built-In Sidechain EQ  High mid-band emphasis and low-cut keeps the low sum and difference frequencies from pumping the upper frequencies of source material
Eight Unique Curves  From the 1:1 mode that warms up signal with low order harmonics without intentional compression, to the Nuke setting, each curve has its own personality, and release shape. The 10:1 Opto ratio uses separate circuitry to emulate the oldest light controlled devices, such as the LA-2A.
Large Knobs with High Resolution Numbering - They're large for easy readability and repeatable settings, and go to 10.5
Locked, Calibrated, Output Level - Allows speed in setting tape and live mix levels
Switchable 115/230 Volt Operation - Extra fuse provided inside unit
Over Designed Power Supplies - Runs cool, allowing cabinet to be sealed without heat vents and features long life components
True Bypass - All contacts doubled up for maximum reliability with no internal audio connectors
XLR and 1/4" Phone Inputs and Outputs - The XLRs are fully balanced with a transformerless design (pin 2 hot, changeable by user to pin 3 hot)
Stereo strappable