(11) EURO CONNECTOR INPUTS
The popular plugable Euro connector is provided for the inputs for each channel. These inputs are balanced electronically, with the terminals marked Ò+Ó as the positive amplifier inputs, and the terminals marked Ò-Ó as the negative amplifier inputs. The remaining terminals are ground (chassis). If possible, always use two-conductor, shielded cables when interconnecting to the amplifier; connecting the twisted pair to the respective Ò+Ó and Ò - Ó terminals of each amplifier channel, and the shields to the amplifier ground. When connecting to a CinemAcoustics Cinema Processor, or
to any signal processor with a balanced output, connect the Ò+Ó, Ò - Ó, and ground inputs of the power amplifier to the respective Ò+Ó, Ò-Ó, and ground outputs of the processor. When connecting the amplifier to a Cinema Processor with a single-ended output, again, use a two-conductor, shielded cable and wire the cable to the amplifier as outlined above. At the processor end, wire the Ò+Ó amplifier input to the Cinema Processor Ò+Ó output, and wire the Ò-Ó amplifier input together with
the amplifier shield to the Cinema Processor ground. The amplifier can be wired in an unbalanced configuration using single-conductor, shielded cables by connecting the single conductor to the Ò+Ó input of each channel, and connecting the shield to both the Ò-Ó input and ground of each channel. A similar connection must be made at the Processor as well. See figure below.
INPUT B INPUT A 
Balanced output from processor
Single-ended output from processor
- + +
Input A is wired in an unbalanced configuration.
Input A is wired in an unbalanced configuration.
Input B is wired in a balanced configuration.
INSTALLATION AND SETUP
The CinemAcoustics Series of power amplifiers is engineered for durability and high performance in theater installations. Each amplifier is internally cooled by an automatic two-speed fan, and is designed to be installed in a standard 19 inch EIA equipment rack. All input and output connections, as well as level controls, selector switches, and the mains circuit breaker are located on the rear panel. The mains power switch, and the LED indicators for power and SPS activation are located on the front panel. The internal cooling fans pull air in from the rear of the unit and exhaust hot air out the front. When the unit is mounted in an equipment rack, an adequate supply of cool air must be available. Due to the internal fan, it is not necessary to leave a rack space between each amplifier in the stack. Upon power-up, the fan will operate at its low speed and will continue to operate at low speed until sustained, high power operating levels occur. Depending upon signal conditions and amp loading, high-speed fan operation may continue or it may cycle between high and low. The cycling of fan speed during active use is normal. The amplifier thermal sensing circuitry may temporarily shut down the amplifier for a variety of reasons. These reasons include an inadequate supply of cool air, a reduction of air flow due to blockage of the amplifierÕs inlet or outlet ports, and severe overloading or short circuit of an output. A temporary shutdown will cause the front panel POWER LED to go dark. Depending upon the fault condition, operation could be restored relatively
