Mesch - In a case of apparent wishful thinking I mistakenly stated that mine is a Mark 2 when it is in fact a Mark 1. It was made in 1985, and around 1990 one channel went out so I sent it to Richard Brown for repair. Since then (25 years) I have had very little reliability issues. In the past few years, very intermittently, one channel will drop in volume. If I turn the amp off and then back on after a few minutes all is back to normal. As I said, this is very intermittent. I was interested in resources for repair as I have to believe that after 30 years of pretty constant use at least some caps and other parts have worn out and need to be replaced for the amp to perform optimally. Your 8 year old Mark 5 is most likely operating as new, with many more years of service left. I am on the precipice of buying a tube amp, but can't seem to let go of the BEL in my system...