Genelex Gold Lion KT-88 reissued tubes

Well, let me provide a little different perspective. I've tried the KT-88 Gold Lion re-issues, and and sad to report their reliablity is very suspect.

I've had four different tubes go out, all withn 100 hours of use. They either experience bias runaway (get cheery red), or they perform a very intensive blue light show, which will promptly take out the associated bias resistor.

All in all, while they do sound good, what good is that if they dont last, and take out your parts? I checked with a well respected audio shop in New York, and they more or less told me the same thing.

So, with that in mind, whats one to do? My stash of GE 6550A won't last forever, so I'm looking for a good sounding RELIABLE 6550/KT88 type that sounds as good as the GE tube. I have one set of 6550C from late 95, and while they are okay, they are not in the same class as the GE. Any suggestions?

Well, sounds like I am not the only one with GL problems. I tried another quad recently, thinking perhaps there production problems were resolved.

Sadly, the problems continue! I had two go Cherry within a week. I researched possible causes of this, and I am convinced that the tube itself is the problem. I think that over time, the internal alignments get altered, or the solder joint on the pins open due to heat, and runaway occurs as a result. I think the metallurgy principals (expansion and contraction) are at work here. GE spent a lot of time and effort getting the 6550A right.

So, where is a good source for the Penta KT-88?