*Please note  -- This pre-owned item may show signs of use. Please refer to the photos for details of the product.  The Aphex Expressor Model 651 is a professional single-channel compressor/limiter designed to provide precise dynamic control while preserving the clarity, punch, and natural character of the original audio signal. Featuring fully adjustable input, threshold, ratio, attack, release, and output controls, the Expressor offers extensive flexibility for recording, mixing, mastering, and broadcast applications. What sets the Model 651 apart is its combination of Aphex's proprietary High Frequency Expander (HFX) and Spectral Phase Refractor (SPR) technologies. HFX helps compensate for the high-frequency dullness commonly associated with heavy compression, while SPR enhances low-frequency clarity and punch without increasing bass amplitude. Additional features include selectable hard- and soft-knee compression, sidechain processing, a low-frequency sidechain filter, and stereo linking capabilities. With servo-balanced audio connections and comprehensive metering, the Aphex Expressor 651 delivers versatile, transparent dynamics processing for professional studio environments.