Maxon CP-9Pro+ Compressor/Limiter


  • Attack Time
    controls how fast the compressor responds to a peak in the input signal
  • Level
    controls the output volume
  • Sustain
    controls the amount of compression


Maxon USA

With the CP-9 Pro+, Maxon has taken one of the most lauded compression circuits of all time and placed it in one amazing little stompbox, creating the most “effective” compressor yet!

More than a reissue, the CP-9 Pro+ features a completely redesigned circuit that is vastly superior to the original 1980's model. The CP-9 Pro+ circuit is based around the patented low-noise DBX compression technology that is used in many high-end pro audio products. This circuit combines a high-quality VCA (voltage controlled amplifier) with an RMS (root mean square) sensor, providing a natural attack response while maintaining an extremely low noise floor generally not found in floor-based units.

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.

Like all Maxon 9-Series models, the CP-9 Pro+ features True Bypass Switching using a 4PDT mechanical switch, feeding your amp with direct, unaltered signal when the effect is disengaged.

Simply put, the CP-9 Pro+ is the last compressor you'll ever need to buy!

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