Cambridge Audio 640 Azur amp

[harcon55]

Hi,

I just received a Cambridge Audio 640 Azur amp a couple of days ago and I've got a question. In the standby mode I hear a slight hum. I've removed and replaced the interconnects, tried using different wall sockets, etc.,--no change. Has anyone else heard this amp and the light hum or is it dead quiet in standby mode?

Thanks,

Harcon55

 

[furrycute]

Could be several things.

1) Does your preamp, or source have a hum? I know most inexpensive receivers have a slight hum when there is no signal going through it.

2) How far are you from the speakers when you detect the hum? If you can only hear the hum when you place your ears right against the tweeter, then that's normal (or I think it is, don't quote me on this).

3) There could be a ground loop problem. Do a search on google for "ground loop" to find solutions.

 

[j_garcia]

640 is an integrated amp. The one that I heard had no hum at all. My first PM7200 developed a noticable hum after a few months as well, and they (local dealer) replaced it no questions asked. It could be heard across the room, even with no source plugged into it. If you hear the hum when your ear is up to the vents, then it is normal. If you hear it from a few feet away, it should probably go back.

Ground loop is a possibility, but if it still hums with nothing connected to it, then that is not it.