So I received a DSL50 in the mail today. The guy said he'd never had it retubed, but I don't know if he is the original owner. I fired it up and it sounded fine, but due to its age I wanted to check for bias drift. It also seemed really hot, with both tubes glowing more than I am used to. This is the first time I've worked with biasing an amp. I pulled off the back panel, turned the amp on and standby on (with a cab attached), and let it warm up for several minutes. I set my MM to 200mvdc. Using the common probe at the center pin and the test probe at either of the side pins, I was getting a measurement around 74 for each side (!). I gather Marshall recommends 45 and many people use 38 or so, and that the 74 would be fair if it were a DSL100, not a DSL50. Am I right about this? Was this set way too high? I turned the bias pots (oddly to me, right seemed to be down) until I got measurements as close to 38 as possible. This seemed to reduce the heat coming from the power section significantly. Am I nuts or a n00b, or did someone retube this and then follow the directions for a 100-watt head?