A surge filter is OK to have between a power amp and the wall outlet. A power line FILTER, such as the TrippLite "Isobar" that has inductors, capacitors etc in-line with the AC is not a good idea because these components have a finite amount of current they can handle. By contrast, a surge protector is nothing more than a MOV across the power line which consumes no power, and is not in series with the AC current. It's only function is to protect from over-voltages which can be very costly for equipment. These two devices are quite different and get confused by people all the time. Of course, the best way to protect against lightning etc. is simply to unplug your components, but you can't always be there to do this

[This message has been edited by soundhound (edited December 23, 2002).]