Genelex Gold Lion KT-88 reissued tubes

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?

For Pentas (and GL's too) I think Doug at http://www.dougstubes.com does a great job w/ matching and general QC. His prices are very reasonable (I remember thinking his shipping charges were sane as well :-) Unlike some tube sellers whom I won't mention, he doesnt pretend to know what you (or your equipment) require. On the other hand, he'll warn you away from danger ;-) So call him if you have detailed questions -- just don't ask him what you'll like!

I run these in my Quicksilvers mid mono's
They work and sound great,I did not like them for the first 150 hours or so, as they were bright sounding,they mellowed out now, and are smooth now with great detail,tone and dynamics.
I would get them again.

Have cary v-12r's vertically bi-amping alon IV Mk II speakers. am very happy with the gold lion kt88 tubes. only had two go bad in 2 years. sound and imaging is superb

I replaced Groove Tube KT88's with the Genalex's in my MFA M120 amps and the improvements were dramatic. The GL's are lovely-sounding tubes at all frequencies. They're probably not even burned in yet,either. :)