Cambridge Audio Azur 540R, Output stage busted?


Novice Member
Hi all. My 4-5 year old Cambridge Audio 540R Azur just started behaving very oddly. I was watching a Youtube video when suddenly there was a high-pitch noise from the amplifier and a text "Overcharge(?) protection" flashed on the LCD. The amplifier shut down and I started wondering if something was wrong in my cables or audio settings.

After I investigated the problem I noticed that the there's an oscillating high pitch noise even if I use the radio tuner as an input, so there's most likely something wrong on the DSP-D/A-Output stage area. The noise is present even with the volume setting "min", and no proper sounds are heard. The noise is slightly different with AM and FM tuners selected so something seems to get through.

I recorded the sound (poorly), you can find it at: dropbox. Is this a known issue? Is there anything I can do?


Novice Member
After letting the amp cool down for an hour and thoroughly vacuuming it trough the grille the noise disappeared. This is something I'd like to not experience again, the amp is situated in an open shelf so the ventilation should be good. Might this be a sign that my amp is going to bust?


Standard Member
I have also had trouble with this amp. It has an issue whereby it is difficult to control the volume. It appears to have some speaker protection relay that malfunctions. This is a guess only as I am no expert. I attempted a reset and the issue was not resolved. The unit also fails to remember whether the front speakers are small or large. It seems to have a range of software glitches as well as relay problems. It also runs very hot. I suspect your amp became very hot and decided to malfunction. I have never owned an amp that exhibited these problems after only a few years of ownership. These issues may have been resolved in the Series II version of this amp. I am, however, not impressed with this av amp. It seems to be a problematic unit.

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