Great-sounding 1U compressor. Largely considered to be exceptional amongst other similar units at its price point. From the manufacturer: "The 501 is two dynamics controllers in one unit. Separately controlled, simultaneous RMS detection and peak limiting is provided so that the limiter can be set to prevent spikes and allow the compressor to control the signals without applying more than the desired amount of gain reduction."

In excellent cosmetic condition, working well.

(Used)