As the title says, I had a tung sol go gassy in my SVT. It has a ding in the envelope, likely from where the tubes were installed and the spring retainer was allowed to slap the top of it. They test at 80% but rattle like you wouldn't believe. A tap with my index finger while holding them sounds like slapping a spring. They all appear to show marks from where they were initially installed as I'm sure the prior owner is a dunce. It has a bit of a roar/crackle at startup, probably(my guess) from one of the rest of them going bad. So, before I get bitten in the rear at a gig again, I think it's probably best I retube this thing. What is the cheapest NOS option? Yes I realize this is a bit of a paradox, but seeing as how golden lions are 350 a sextet that can't be too far off what actual good tubes cost. Failing this, what is the most reliable 6550 out there that's new? I've had poor experience with JJ, but they're so cheap I could buy several sets and sort the hyper ones out for stable ones. Looking into the glass on the groove tube spares I had, they're exactly the same plate structure as the tung sol, so I'm assuming all new sensor tubes are the same. Funny enough, the bottom of the barrel chinese 12ax7s I have in it(from spares, tested 98 to 102% if you can believe that) with no names have been utterly reliable, with no issues at all to report. I know TAD has got a GE 6550A reissue, but no one really seems to be familiar with these. I'm wary of China tubes as I think most of y'all probably are but if they work and don't fail, I'd be willing to try it. Live and learn, I suppose.