Cambridge Audio Azur 340A SE User Manual

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Cambridge Audio Azur 340A SE User Manual Manual pdf 13 page image

340A/340A SE Integrated amplifierAzur integrated amplifier 13Remedy - Ensure ventilation is not obstructed, and loudspeakers are notof too low impedance. Switch the amplifier off for 15 minutes to cooldown if necessary.3. DC offset protectionIndicator - Amplifier will not operate; all input LEDs are flashing.Description - The DC offset protection system immediately isolates theamplifier from the loudspeakers by positively opening an output relay, inthe unlikely event of an amplifier fault. Errors of either polarity on bothchannels are detected.Remedy - This can sometimes be triggered by excessive mains noise etc;if so switching the unit off and on again will reset it. If unit will not resetthen there is an amplifier fault that will require servicing. Switch the unitoff and contact your dealer.4. Voltage clampingWhen rapid transients are applied to reactive loads in extremecircumstances, flyback pulses can be generated which are larger thanthe amplifier supply rail voltages and have the potential to cause harmto the output devices. The amplifier has a comprehensive voltageclamping system that ensures that such pulses are safely absorbed bythe amplifier and no damage can result.The Azur 340A/340A SE protection system comprises of:1. Overload and Short-Circuit ProtectionIndicator - Output distorted and at unexpectedly low level.Description - The amplifier is fully protected against excessively low loadimpedances. The overload and short-circuit protection systemscontinuously monitor the voltage, current and temperature conditions ofeach of the output devices, and comparing them with the defined SafeOperating Area or SOA. This sophisticated system allows the protectionto act positively in case of genuine necessity, but without falsetriggering.Remedy - Check loudspeaker impedance is not too low. Very oftenloudspeakers of too low an impedance can be driven at low levels butnot high levels.2. Over temperature detectionIndicator - Output appears to cut out frequently, independently on thetwo channels.Description - The instantaneous temperatures of the output devices ofthe amplifier are continuously monitored to ensure that junctiontemperatures do not get dangerously high. When an over temperaturecondition occurs, the output is muted until the devices cool. Theoperation is carefully controlled to minimise the exposure of the outputdevices to wide temperature variations, which can impair reliability bythermal cycling. This is accomplished by making the muting periodsrelatively short, so the amplifier appears to be turning on and off. Thisputs the least stress on the output devices.PROTECTION SYSTEM