The CP-9 Pro+ has Threshold, Ratio, and Gain controls that are extremely interactive and allow for a variety of useful applications for the unit. With a maximum compression Ratio of ?:1 (no increase in output level, regardless of level) the Pro+ can be used as a limiter to balance volume levels. At medium Threshold settings a variety of compression effects from “pinched” notes to shimmering, sustained arpeggios can be achieved by simply varying the Ratio and Gain knobs. With a maximum Gain of +30 dB and Threshold set at 1:1 (no compression) the Pro+ can also be used as a clean booster to slam the front end of your amplifier or other effects units. The CP-9 Pro+ has the highest Gain available from a pedal compressor, making it possible to achieve a balanced output at any compression setting. A Reduction status LED accurately displays the degree of the compression effect for the user to see when the unit is engaged.

To offer improved performance, Maxon has added their proprietary DC-DC stabilized voltage converter to this DBX-based compression circuit. The converter takes the 9 volt (+/- 4.5 volts) input power and bumps it up to 18 volts (+/- 9 volts). Operation in this voltage range provides a wider dynamic range than ordinary compressors while allowing maximum head room to prevent input distortion. This fuller frequency response makes the CP-9 Pro+ ideal for use with Bass or Keyboards as well as today’s high-gain guitar pickups and electronics.