340A/340A SE Integrated amplifier
PROTECTION SYSTEM
The Azur 340A/340A SE protection system comprises of:
1. Overload and Short-Circuit Protection
Indicator - Output distorted and at unexpectedly low level.
Description - The amplifier is fully protected against excessively low load impedances. The overload and
Remedy - Check loudspeaker impedance is not too low. Very often loudspeakers of too low an impedance can be driven at low levels but not high levels.
Remedy - Ensure ventilation is not obstructed, and loudspeakers are not of too low impedance. Switch the amplifier off for 15 minutes to cool down if necessary.
3. DC offset protection
Indicator - Amplifier will not operate; all input LEDs are flashing.
Description - The DC offset protection system immediately isolates the amplifier from the loudspeakers by positively opening an output relay, in the unlikely event of an amplifier fault. Errors of either polarity on both channels 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 reset then there is an amplifier fault that will require servicing. Switch the unit off and contact your dealer.
2. Over temperature detection
Indicator - Output appears to cut out frequently, independently on the two channels.
Description - The instantaneous temperatures of the output devices of the amplifier are continuously monitored to ensure that junction temperatures do not get dangerously high. When an over temperature condition occurs, the output is muted until the devices cool. The operation is carefully controlled to minimise the exposure of the output devices to wide temperature variations, which can impair reliability by thermal cycling. This is accomplished by making the muting periods relatively short, so the amplifier appears to be turning on and off. This puts the least stress on the output devices.
4. Voltage clamping
When rapid transients are applied to reactive loads in extreme circumstances, flyback pulses can be generated which are larger than the amplifier supply rail voltages and have the potential to cause harm to the output devices. The amplifier has a comprehensive voltage clamping system that ensures that such pulses are safely absorbed by the amplifier and no damage can result.
Azur integrated amplifier 13