Crest Audio Stereo Amplifier owner manual Indicators, Protection Features

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Indicators

Professional Series amplifiers feature four front panel LED indicators per channel: Clip/Limit, Signal, Temp/DC, and Active. These LED indicators inform the user of each channel’s operating status and warn of possible abnormal conditions.

Clip/Limit LED

A channel’s Clip/Limit LED will light dimly at the onset of clipping and increase in brilliance as clipping becomes more severe, stay- ing on until the clipping ceases. If the LED’s are flashing quickly and intermittently, the channel is just at the clip threshold, while a steady, bright glow means the amp is clip limiting, or reducing gain to prevent severely clipped waveforms reaching the loudspeakers. See the Clip Limiting section for more information.

Signal LED

This LED lights when its channel produces an output signal of about 4 volts RMS or more (0.1 volt or more at the input, with 0 dB attenuation and standard X40 voltage gain). It is useful in determining whether a signal is reaching and being amplified by the ampli- fier.

Temp/DC LED

The Temp/DC LED lights to indicate that the channel’s output relay is open, disconnecting the speaker(s) for any of the following rea- sons:

1.The unit was just powered up and is in the turn-on delay mode.

2.The amplifier senses a DC voltage at its output.

3.The channel has overheated.

Active LED

The Active LED indicates that its channel’s output relay is closed and the channel is operational. It lights under normal operation and remains on even when the channel is in clip limiting or IGM gain reduction. These are protection features which leave the output relay closed. If the Active LED goes off, there is no signal at the module output point.

Protection Features

Professional Series amplifiers incorporate several circuits to protect both themselves and loudspeakers under virtually any situation. Crest Audio has attempted to make the amplifiers as foolproof as possible by making them immune to short and open circuits, mis- matched loads, DC voltage, and overheating. If a channel goes into the clip limiting or IGM gain reduction mode, the speaker load remains connected, but clipping percentage or output power are instantly reduced. When a problem occurs that causes a channel to go into a protection mode, the Temp/DC LED for that channel will glow. DC voltage on the output, excessive subsonic frequencies, or thermal overload will cause the channel’s output relay to disconnect the speaker load until the problem is corrected or the amplifier cools down.

Clip Limiting

Any time a channel is driven into hard, continuous clipping, the clip limiter circuit will automatically reduce the channel gain to a level just slightly into clipping, guarding the speakers against the damaging high power continuous square waves that may be produced. Situations that may activate the clip limiter include uncontrolled feedback, oscillations, or an improper equipment setting or malfunc- tion upstream from the amplifier. Normal program transients will not trigger the clip limiter; only steady, excessive clipping will. The Clip/Limit LED will glow brightly and continuously when limiting occurs.

IGM Impedance Sensing

Professional Series amplifiers feature innovative circuitry that allows safe operation into any load. When an amplifier sees a load that overstresses the output stage, the Instantaneous Gain Modulation (IGM) circuit adjusts the channel gain to a safe level. This method of output stage protection is far superior to conventional, brute force type limiting found on other amplifiers. Like the clip limiter, the IGM circuit is sonically transparent in normal use and unobtrusive when activated.

Crest Audio Pro Series Power Amplifiers

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Contents Including MA Series Amplifiers Important Precautions Table of Contents Introduction UnpackingMounting Cooling Requirements Operating PrecautionsCrest Audio Model 7301 Power Amplifier Crest Audio Model 10004 Power AmplifierModel 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 FeaturesNexSys Connecting InputsConnecting Outputs Octal Accessory SocketsOperation 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

Stereo Amplifier specifications

The Crest Audio Stereo Amplifier has established a notable reputation in the audio industry, particularly among professionals seeking dependable and high-performance amplification solutions. Renowned for its robustness and exceptional sound quality, this amplifier is a popular choice for both live sound applications and studio settings.

One of the standout features of the Crest Audio Stereo Amplifier is its outstanding power output, which ensures that it can drive a wide range of loudspeakers with ease. Typically available in various power ratings, these amplifiers can provide significant wattage, allowing them to handle high-demand audio situations without distortion. This makes the Crest Audio amplifier an excellent choice for large venues, theaters, and event spaces.

The design of the Crest Audio Stereo Amplifier prioritizes efficiency and performance. Utilizing high-quality components, the amplifier is constructed with a rugged chassis and offers extensive heat dissipation to ensure longevity and reliability during prolonged use. This durability is particularly crucial in professional settings where equipment is often subjected to rigorous conditions.

In terms of technology, Crest Audio amplifiers incorporate advanced circuitry that enhances audio fidelity and minimizes noise. The use of Class AB amplification technology allows for a balanced performance that delivers both output power and audio clarity. This technology enables the amplifier to produce rich, warm tones, making it particularly effective for musical genres requiring dynamic range and precision, such as classical and jazz.

Another notable characteristic of the Crest Audio Stereo Amplifier is its comprehensive protection features. These amplifiers are designed with built-in thermal, short circuit, and overload protection, ensuring that the equipment can withstand potential hazards without compromising performance. The intuitive LED indicators provide visual feedback on the status of the amplifier, allowing users to monitor operation easily.

Connectivity is another essential factor, with Crest Audio amplifiers typically featuring a variety of input and output options. This flexibility enables integration with different audio systems, whether for simple stereo setups or complex multi-channel configurations. The professional-grade speakON and binding post outputs ensure secure connections to loudspeakers, promoting optimal performance.

Overall, the Crest Audio Stereo Amplifier is a reliable, high-performance solution for any audio professional. With its powerful output, sturdy construction, advanced technology, and user-friendly features, this amplifier continues to be a top choice for delivering exceptional sound quality in various applications. Whether in a studio environment or a live concert setting, the Crest Audio Stereo Amplifier stands out as a trusted tool for achieving audio excellence.
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