Crest Audio Stereo Amplifier owner manual Connecting Power, Operation Modes

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Connecting Power

Professional Series power amplifier power requirements are rated at:

a)“idle”

b)1/8th power (“typical” music conditions)

c)1/3rd power (“continuous” music conditions) d.) maximum rated power.

Never try to hold the power switch in the “ON” position if it won’t stay there itself! Always turn off the amplifier before changing operating modes!

The maximum power current draw rating is limited only by the front panel circuit breaker. Consult the specifications in the Appendices section for figures on the current that each amplifier will demand. Make sure the mains voltage is correct and is the same as that printed on the rear of the amplifier. Damage caused by connecting the amplifier to improper AC voltage is not covered by any warranty. Unless otherwise specified when ordered, Crest amplifiers shipped to customers are configured as follows:

North America

-

120VAC / 60Hz

Europe

-

230VAC / 50Hz

Asia

-

220VAC / 50Hz

Australasia

-

240VAC / 50Hz

South America

-

120VAC / 60Hz or 220VAC / 50Hz

Japan

-

100VAC / 50Hz

NOTE: Always turn off and disconnect the amplifier from mains voltage before making audio connections. Also, as an extra precau- tion, have the attenuators turned down during power-up.

Operation Modes

Stereo Operation

For stereo (dual channel) operation, turn the amplifier off and set the mode select switch to the stereo position. In this mode, both chan- nels operate independently of each other, with their input attenuators controlling their respective levels. Thus, a signal at Channel A’s input produces an amplified signal at Channel A’s output, while a signal at Channel B’s input produces an amplified signal at Channel B’s output. For models 9001 and 10004, the recommended minimum nominal load impedance for stereo or parallel operation is 2Ω per channel. For model 10001, the minimum is 1 ohm per channel. Note: The Model 7301 has no mode select switch; it always operates as a dual-channel amplifier. Model 10004 has two mode select switches, one for channels A/B, and one for channels C/D.

Parallel Operation

For parallel (dual-channel/single input) operation, turn the amplifier off and set the mode switch in the parallel position; both amplifi- er channels are then driven by the signal at Channel A’s input. No jumper wires are needed. Output connections are the same as in the stereo mode. In the parallel mode, only Channel A’s input is active; Channel B’s is out-of-circuit. Both input attenuators remain active, allowing you to set different levels for each channel. Power and other general performance specifications are the same as in the stereo mode. Note: Model 7301 has no mode select switch; it always operates as a dual-channel amplifier.

Bridged Mono Operation

Both amplifier channels can be bridged together to make a very powerful single-channel monaural amplifier. Use extreme caution when operating in the bridged mode; potentially lethal voltage may be present at the output terminals. To bridge the amplifier, set the rear panel mode select switch to the bridge position. Apply the signal to Channel A’s input and connect the speakers across the hot outputs (the “+” binding posts of Channels A and B).

Unlike the stereo and parallel modes, in which one side of each output is at ground, in the bridged mode both sides are hot. Channel A’s side is in phase with the input. For proper operation, both input attenuators must be in the same position. This keeps the load bal- anced between the channel outputs. As in the parallel mode, only Channel A’s input is active. Note: The Model 7301 cannot operate in bridged mono mode; it always operates as a dual-channel amplifier. See the separate section on this model.

Bridged Mono Operation - Model 10004

The Model 10004 power amplifier is configured so that one or both pairs of channels can be bridged to mono. Using the rear panel mode select switches, follow the same procedures as outlined above to bridge channels A&B together and/or C&D together.

Crest Audio Pro Series Power Amplifiers

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Contents Including MA Series Amplifiers Important Precautions Table of Contents Unpacking IntroductionMounting Crest Audio Model 7301 Power Amplifier Operating PrecautionsCrest Audio Model 10004 Power Amplifier Cooling RequirementsModel 4601 & 7001 Features Models 3301, 4801, 6001 FeaturesLowshighs Model 7301 Features8001 Model 8001 FeaturesModel 9001 Features Professional Power Amplifier Model 10001 FeaturesCh a Ch B Ch C Ch D Model 10004 FeaturesConnecting Outputs Connecting InputsOctal Accessory Sockets NexSysOperation Modes Connecting PowerSwitches & Controls Bridging PrecautionsProtection Features IndicatorsThermal Protection Speaker ProtectionService / Warranty Information Amplifier Maintenance and User ResponsibilityChannel a Appendix B General Amplifier Specifications Model 1kHz, 0.012% THD+N 20Hz-20kHz, 0.05% THD+N 8Ω Stereo Power 1kHz, 0.025% THD+N 20Hz-20kHz, 0.05% THD+N 8Ω Stereo Power 430W 400W 1kHz, 0.02% THD+N 20Hz-20kHz, 0.05% THD+N 8Ω Stereo Power Both Channels @ 4Ω 750W 720W 1kHz, 0.02% THD+N 20Hz-20kHz, 0.1% THD+N 8Ω Stereo Power 1Ω Stereo Power 4Ω Stereo Power x4 ch Appendix C Wire Gauge Charts MA5850 Appendix D Meyer-Compatible Power AmplifiersMA7120 Power is serious business