So I've come into the possession of these 2 Marshall 9005 EL34 stereo (2X50 watt) poweramps. The good one I'll probably trade in for some odd hunk of old junk at a music store eventually. But the other one... 2 sides, A and B. I have tried swapping tubes, and even having the bias set as cold as possible to see if the problem went away. It didn't. Problem: side B works fine, sounds great. Side A sounds great for 5 seconds after it is switched out of standby, then the power tubes outshine the sun and a thermonuclear reaction begins. Angry red, dark at first but gets bright quickly, from the center of the 2 power tubes on side A. I know, take it to a tech. But techs want money, they weren't happy the last time I tried to pay with a handful of mud and some twigs. I'm thinking it's fixable, but expensive. The previous owner had a preamp blow up - smoke and everything - and hasn't used it since, I got it free as junk. What I am wondering - is it safe to use just side B? Pull the tubes and fuse from A, have no speaker plugged in, leave it on standby forever? Any thoughts? Thanks!