Originally Posted by Pat315
I can't remember those ever coming on before not if the amp is under powered or just old.
if you didn't get clipping before but get clipping now, the most likely explanation is that you are pushing the amplifier a little harder. There are many possible explanations for this.
One possible cause that you probably don't want to hear about is either long term or short term loss of sensitivity of your ears. This loss may be short term due to something like a head cold, or it can be long term and the consequence of of things like aging.
It might be as simple as playing different recordings that make different demands on your system. For example, recordings that distribute more of their energy to the frequency extremes take more power for equal loudness than recordings that focus more of their energy in the middle range.