amp or speakers?

[bing...@gmail.com]

I've had my audio system over yen years now, and recently I've noticed the sound breaking up into static at certain fairly high frequencies. I can't locate the breakup to any one speaker, so I'm guessing my amp/receiver is going bad. Is there anything else I can try to diagnose the problem? When I play Sarah Brightman's Bailero, her high notes really break up into static