User manual CREST AUDIO CA SERIES

[. . . ] PROFESSIONAL POWER AMPLIFIERS Professional Power Amplifier Professional Power Amplifier Professional Power Amplifier Professional Power Amplifier Professional Power Amplifier Professional Power Amplifier OWNER' S MANUAL Important Precautions This symbol is used to alert the operator to follow important operating procedures and precautions detailed in documentation. This symbol is used to warn operators that uninsulated "dangerous voltages" are present within the equipment enclosure that may pose a risk of electric shock. 10. Power down & disconnect units from mains voltage before making connections. Never hold a power switch in the "ON" position if it won't stay there itself! [. . . ] Drawn in by dual 45 cubic feet-per-minute (CFM) fans on the rear panel, air flows through the cooling fins of the channel heat sinks (dissipating power transistor heat), then exhausts through the front panel slots. The "intelligent" variable-speed DC fans are controlled by heat sink temperature-sensing circuits. When the amplifier is turned on, the fans briefly "rev up, " then slow to an idle; this indicates that the temperature sensing circuits are operating normally. The fan speed increases only as required by heat sink temperatures, keeping fan noise to a minimum. Under extreme thermal load, the fans will force a very large volume of air through the heat sinks. If either heat sink surpasses the maximum allowed temperature, the sensing circuit will open the output relay, disconnecting the load from that channel. If the power transformer overheats, another sensing circuit opens both channel output relays until the transformer cools to a safe temperature. IMPORTANT: To ensure optimum cooling, periodically clean the amplifier fan filters (removable without tools). Also make certain that there is enough space around the front of the amplifier to allow the cooling air to escape. If the amplifier is rack-mounted, do not use doors or covers on the front of the rack; the exhaust air must flow out without resistance. If the amplifiers are to be housed in racks with closed backs, allow at least one (1) standard rack space of opening in the front of the rack for every four amplifiers. Crest Audio CA Series Power Amplifiers Models CA2, CA4, CA6, CA9, CA12, CA18 Page 9 Connecting Inputs. Use either the XLR or 1/4-inch input connectors on the rear to supply audio signals to your Crest Audio CA Series amplifier. (The CA Series amplifiers are configured standard with "Pin 2 hot" on XLR inputs. Please note that some other Crest Audio amplifiers are configured with "Pin 3 hot"). The unused connector can be used to jumper the audio input to another amplifier input. For more information, see the sections on Balanced 1/4" (TRS) & XLR Input Connectors, Input XLR Polarity, and Input Sensitivity. Speakers are connected using 5-way Output Binding Posts or Speakon connectors, depending on version supplied. Please note that on the 5-way Output Binding Post version of the CA18, two pairs of 5-way binding posts are provided for each channel, so that paralleling of speakers is possible. For more information, see the Output Connectors and Mode Selection sections. Page 10 Crest Audio CA Series Power Amplifiers Models CA2, CA4, CA6, CA9, CA12, CA18 Mode Selection. The three-position, recessed Mode Select switch (located on the rear panel) configures the amplifier for either Stereo, Parallel or Bridged Mono Mode. In Stereo Mode, both channels operate independently, with their input attenuators controlling their respective levels. Signal at Channel A's input produces output at Channel A's output, while signal at Channel B's input produces output at Channel B's output. Recommended minimum nominal load impedance for stereo operation is 2 ohms per channel. [. . . ] Read the section on Speaker Protection and always be aware of the speaker's continuous and peak power capabilities. Crest Audio is not responsible for damage to loudspeakers for any reason. Service and Repair In the unlikely event that your amplifier develops a problem, it must be returned to an authorized distributor, service center or shipped directly to our factory. To obtain service, contact your nearest Crest Audio Service Center, Distributor, Dealer, or any of the worldwide Crest Audio offices. Because of the complexity of the design and the risk of electrical shock, all repairs should be attempted only by qualified technical personnel. [. . . ]