Not the speaker as I have already interchanged HPM-100's to troubleshoot. The problem is alway on the right channel so it's isolated to the 1250 right channel. It occurs with the volume up to around the 10:30 or better (-28 db) on CD's and LP's even with the low filter engaged. Turn down the volume and no problem. What board should I start looking at first? I'm guessing some caps are going south as I never really had a problem before but all are original. On another note that might help to solve this the right side heat sinks are a bit cooler than the left side ones. Both seem to coincide with my new problem. ?????????????????