May 30, 2005

My receiver has blown its fuses twice. Q: Is it my fault, or could the unit be incompatible with the wiring in my house?

Joe B.

A: Unless it's a piece of equipment designed to be used In another country with a different AC voltage, your problem is unlikely to be caused by incompatibility with your wiring.

One possibility is that you are simply driving your system too hard, and the fuses are blowing before the speakers do. Very insensitive speakers need lots of power, and very high volume levels can keep the amplifier clipping a lot of the time. The solution is to turn the level down or buy more-sensitive speakers. Or turn the power-hungry low frequencies over to a powered subwoofer.

Another cause could be a very low impedance presented to the receiver's output stage. If you are driving two sets of speakers, there is a good chance that the total impedance at some frequencies is low enough to demand more current than the amplifier can handle.

Or you may have an intermittent short circuit that causes the fuses to blow. Check the connections both on the back of the amplifier and at the speakers themselves to make sure there are no little wisps of wire that can touch the other terminal.

Otherwise, your receiver may have an Internal fault, and this will require service.

...Ian G. Masters