Check the listing for details. elysia mpressor 500 Series Compressor. Condition: Very Good - Refurbished. Listed at 687.69 USD. An mpressor for Your 500 Series Rack! The mpressor 500 brings the signal-shaping prowess of elysia’s acclaimed rackmount mpressor to the 500 Series format. Streamlined for the space constraints of a single-wide module, the mpressor 500 is mono and lacks the EQ circuitry of its bigger brother, but as a compressor, it delivers the powerful punch, flexible dynamics shaping, and highly detailed Class A sonics you expect. Its sound and versatility make the mpressor 500 ideal for both recording and mixing, and its special features give it capabilities far beyond most conventional compressors. Like its 19-inch rackmount sibling, the mpressor 500 features negative ratios, extreme time constants, Anti Log release, and elysia’s proprietary gain reduction limiting.