User manual CREST AUDIO CPX

[. . . ] owner's manual CPX SERIES CPX power amplifier 20 16 6 (dB) 32 23 26 29 20 23 26 29 (dB) 32 ON A SIG GCLTM B GCLTM SIG 16 6 PWR PWR CPX 2600 POWER AMPLIFIER POWER CPX 900 CPX 1500 CPX 2600 important precautions 1 Save the carton and packing materials!Should you ever need to ship the unit, use only the original factory packing. For replacement packaging, call Crest Audio's Customer Service Department directly. Do not run the output of any amplifier channel back into another channel's input. [. . . ] Operation above 4 ohms per channel and even open-circuit conditions can always be considered safe, but sustained operation at loads below 2 ohms could result in temporary amplifier shut down due to the thermal limit circuitry. 3 10 Speakon outputs CPX amplifiers utilize three 4-conductor Speakon connectors, one for each channel and one for BRIDGE mode. Please refer to the BRIDGE MODE section of this manual before attempting to use this mode. For each channel Speakon, the same impedance rules apply as with the binding posts. Internally, all the Speakons are wired in what is called the "high current" mode, with pins 1+ and 2+ in parallel, and pins 1- and 2- in parallel. For the CHANNEL A and CHANNEL B Speakons, the respective channel output appears on pins 1+ and 2+. For the BRIDGE Speakon, CHANNEL A appears on pins 1+ and 2+, and CHANNEL B appears on pins 1- and 2-. Always check the Speakon connector wiring carefully before using. 11 Mode switch This switch is used to select STEREO or BRIDGE mode operation. It is a conventional push-push type, requiring a small "tool" to activate. Accidental selection of this mode could damage loudspeakers, particularly in bi-amped systems. Amplifier BRIDGE mode theory will be covered later in this manual. p. 17 3 features overview CPX Rear Panel CPX owner's manual CAUTION BREAKER 15 A M P CHANNEL B BRIDGE CHANNEL A CHANNEL A INPUT LOW CUT + WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE. AVIS: RISQUE DE CHOC ELECTRIQUE-NE PAS OUVRIR. 150 Hz X OVER BRIDGE OUT STEREO/ IN BRIDGE A BAL. LOW Z GND HIGH Z - BRIDGE GCL TM OUT ENABLE / IN DEFEAT THRU HIGH OUT LOW OUT LOW CUT MOUNT IN RACK ONLY - INSTALLER SUR SUPPORT DE MONTAGE SEULEMENT CHANNEL B OUTPUT CHANNEL A CHANNEL B INPUT 12 13 14 15 p. 18 + 150 Hz X OVER B - - + + - features overview rear panel 12 GCL (Gain Comparator Limiter) switch This switch is used to enable or defeat the GCL limiter circuitry. It is also a conventional push-push type, requiring a small "tool" to activate. Normally, the GCL function should be enabled to minimize the possibility of either or both channels going into clipping or overload. With this feature defeated, a severe overload could cause the mains circuit breaker to trip. The Crest GCL limiting system will be covered in greater detail later in this manual. 3 13 Fan grill A 2-speed DC fan supplies cool air to the amplifier. The fan switches to high speed automatically when the unit requires additional cooling. The fan should never stop unless the amplifier is switched OFF or the AC mains power source is interrupted. 14 Combo input connector The combo connector offers both female XLR and ¼" phone jack balanced inputs for each channel. The XLR is wired with pin 1 as ground, pin 2 positive input, and pin 3 negative input. The ¼" phone jack is a tip/ring/sleeve (3-conductor) type, with the tip being positive input, the ring negative input, and the sleeve ground. [. . . ] It is not necessary to leave a rack space between each amplifier in the stack since each fan pulls air in from the rear and exhausts the hot air out the front. However, an adequate cool air supply must be provided for the amplifier when rack mounted. The internal fan must have a source of air that is not preheated by other equipment. The amplifier will start up in low speed fan operation and will normally stay at low speed unless sustained high-power operating levels occur. [. . . ]