I've had some problems with my ST-120 blowing up. Some time back you had me replace the cap-can, and that helped a lot. But a couple of weeks ago I did it again; I turned off the ST-120, then (mistakenly) turned it right back on. It blew the slo-blo fuse, it flashed the Ruby 5AR4 rectifier tube, and apparently took out a KT-88 (or two).
I replaced these three items (fuse, rectifier, and KT88) and all has been fine, but I'm still nervous.
I didn't know about the potential use of a Weber WZ68 on my ST-120. Would this help?
I have ordered a Weber Copper-Cap GZ34, plus I bought a GZ33/CV5745 Mullard NOS tube off eBay that you mentioned somewhere, plus I also have "1 NEW IN THE BOX 1961 MULLARD GZ34 5AR4 TUBE" that I just won on eBay coming in.
My ST-120 is on a big APC UPS, in order to avoid momentary power outages.
Can you take a moment to describe rectifier tube choices on the ST-120, and their pros and cons, especially with regard to holding up to power cycling.
PS: I've also 'upgraded' by power cord to a 3-wire grounded cord, and attached the ground to the chassis. Was this a good or bad move?