Diamond CPR-JR Compressor Jr. Optical Compressor w/ EQ Cactrol opto-isolator variable resistance path as used in high-end studio compressors for smooth attack and decay characteristics while preserving initial signal transients. Post-compressor tilt EQ provides a very musical tailoring of frequency response seamlessly transition from a darker jazz voicing to a bright jangle, with flat frequency response at the center detent position. Optimized gain staging and use of ultra low noise transistor and opamps in signal path for lowest possible noise and extended signal headroom. Premium audio components, including tight tolerance Panasonic PPS capacitors and metal film resistors. Top mounted jacks on a small enclosure for tight pedalboard layouts.