I have a 800 watt kenwood bridged to a sub that has worked flawlessly for 8 years. Suddenly it keeps blowing the 30 amp in line fuse. I put in a new fuse and it powers up. As soon as I turn my volume up to 30 it blows again(on a scale of 0-50). Below volume level of 30 it plays fine. The amp does seem excessively hot to the touch for only running about a minute. I verified the cooling fan is running. Seems to me if it was grounding out, it would blow immediately. Any ideas?