COMPRESSION PEDAL Compression pedal. 100% analog. Class A. With incredible dynamics. Studio quality optical compressor. Very natural sound. Inspired by vintage compressors, it adds depth and bass to the guitar. Adjustable Attack and Release times. 12dB Clean Boost. Internal voltage at 18v for greater dynamics and cleaner compression. Transparent bypass. Controls: Volume (output level), Squash (compression level), Release, Attack, Chime (brightness). Operation: 9V Battery or optional 9V-12V DC Adapter. Dimensions: 9.5 × 6.5 × 13cm. Weight: 495g.