User manual CREST AUDIO CD

[. . . ] CD CD Power Amplifier Owner's Manual Intended to alert the user to the presence of uninsulated "dangerous voltage" within the product's enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons. Intended to alert the user of the presence of important operating and maintenance (servicing) instructions in the literature accompanying the product. WARNING:To prevent electrical shock or fire hazard, do not expose this appliance to rain or moisture. Before using this appliance, read the operating guide for further warnings. Este símbolo tiene el propósito, de alertar al usuario de la presencia de "(voltaje) peligroso" sin aislamiento dentro de la caja del producto y que puede tener una magnitud suficiente como para constituir riesgo de descarga eléctrica. [. . . ] If you ever need to ship the unit anywhere without mounting it in a rack, you should take advantage of the original factory packing materials in order to avoid unnecessary damage. CD owner's manual For replacement packaging, call Crest Audio's Customer Service Department directly. + see--service and support mounting All CD Series amplifiers mount in standard 19-inch racks and occupy two rack spaces. Rear mounting ears give additional support and use of rear supports is highly recommended in all mobile and touring sound systems. Handles are available as an option (P/N: C32000010). CD dimensions front width 19. 00" /483mm front height 3. 47" / 88 mm rear width 17. 12" /435mm front height 3. 47" / 88mm 2 3 1 2 3 1 depth (from rack rails)16. 55" /420mm rack mount dimensions 16. 05" / 407mm p. 6 installation cooling and ventilation CD amplifiers use a forced air cooling system to maintain a low, even operating temperature. Air is drawn in by a DC fan on the rear panel, flows through the cooling fins and then exhausts through the front panel vent. Heat sink temperature is monitored and controls the variable speed fan. If the heat sink surpasses its maximum allowed temperature, the thermal protection circuit will activate and open the output relays allowing the amplifier to cool to a safe temperature. Normal operation will resume once the amplifier cools to a safe level. Thermal protect activation only occurs under extreme thermal conditions and is not part of normal operation. 2 a Make certain that there is enough space around the front and rear of the amplifier to allow the heated air to escape. When mounting in a rack, try to avoid using doors or covers on the front and rear of the enclosure; the exhaust air must not be impeded suggestion In racks with closed backs allow at least one standard-rack-space opening for every four amps. powering Unless otherwise specified when ordered, CD amplifiers are supplied factory set to following voltage options : Option 1 US domestic nominal 120Vac 60Hz for rated power output (safe operating range 100 - 132Vac ) Option 2 export models nominal 230Vac 50Hz for rated power output (safe operating range 200 - 253Vac ) maintenance On some CD amplifier models the fan is supplied with a removable foam filter. This filter should be cleaned periodically with compressed air. If the amplifier is used in an extremely dusty or smoky environment , the unit should be periodically blown free ( using compressed air ) of any foreign matter that may have built up inside the unit. Users will not need to make any adjustments to the amplifier during its lifetime. There are no user-serviceable parts or adjustments that require opening the amplifier. p. 7 features overview 3 / location of connectors and controls legend of panel symbols front panel / rear panel p. 9 3 features overview CD shown CD owner's manual 1 2 3 456 7 8 9 p. 10 features overview front panel 1 Rack Mounting Ears Two front-panel mounting holes are provided on each mounting ear. 3 2 Channel Level attenuators Two input attenuators adjust level for their respective amplifier channels in stereo and in parallel modes. In Bridged Mono mode, the channel A attenuator controls overall signal level for both channels (see rear panel mode switch description). 3 Protect This Red LED indicates that the amp channel is in Protect mode. During Power up, the amp briefly goes into protect mode in order to prevent any loud spikes from being fed to the speakers. After a few seconds the amp comes out of protect mode and is ready for normal operation. If the amp stays in Protect mode, this indicates that there may be a problem internal to the amp. If the amp goes into Protect mode during operation this indicates that either a problem has developed internal to the amplifier or the amplifier is being over-stressed due to an over-current (short circuit or a load impedance below the operating range), or thermal condition. In this event, the amplifier should be switched OFF, and the load connections checked for shorts and proper load impedance. If overheating is suspected, allow the amplifier to cool and check that the airflow is not impeded. 4 ACL / IGM This Red LED illuminates when either the ACL or IGM protection circuitry is engaged. [. . . ] Only steady or excessive clipping (not normal program transients) will trigger ACL. The circuit is virtually transparent in operation and full signal bandwidth is maintained. IGM INSTANTANEOUS GAIN MODULATION IGM is an innovative circuit that allows the amplifier to operate safely into loads as low as 4 ohms. When the amplifier sees a load that overstresses the output stage, the IGM circuit adjusts the channel gain to a safe level. In addition, if extreme and sustained low impedance is encountered, the amplifier's output relay will open. [. . . ]