The DBX 166A is a vintage 2-channel compressor/limiter/gate designed for both live sound and studio applications. It is known as a workhorse unit that provides robust dynamic control over audio signals, from smoothing out uneven levels to adding punch to drums. The 166A offers versatile compression options, including both the classic "hard knee" and DBX's proprietary "OverEasy" modes for a smoother transition into compression. 

The DBX 166A is a rack-mountable dynamics processor that integrates a compressor, limiter, and an expander/gate into a single 1U device. Each of its two independent channels features a complete set of controls, including adjustable threshold, ratio, attack, and release, as well as an output gain control. For simpler operation, it includes a "Classic Auto" mode that automatically sets the attack and release times. The built-in noise gate helps to reduce unwanted background noise. It also offers a "Contour" function that prevents low-frequency content from excessively triggering the compressor, preserving the high end of the mix. The 166A can operate in dual mono or linked stereo modes, making it adaptable for a variety of audio processing needs, from individual instrument tracks to stereo bus compression.