Diamond CPR-1 Compressor - Opto Comp and EQ Pedal w/ 4 Cables Post-compressor 'tilt' EQ provides a very musical tailoring of frequency response - seamlessly transition from a darker jazz voicing to a brighter jangle, with flat frequency response at the center detent position. Premium audio components, including 2% polypropylene capacitors,1% metal film resistors and a pro audio grade opamp (our signal path opamp alone costs 8 to 10 times what the industry norm uses).