Genelex Gold Lion KT-88 reissued tubes

I run a pair of Sonic Frontiers SFM-160s which each use a MQ of GL KT-88s. The amps were bought used, then shipped directly to Chris Johnson for a comprehensive check-up and his SE+ mod. The GL KT-88s were "standard" issue for the SE+ mod.

That was two years ago. Since then, I have lost three GLs on three separate occasions, each time taking with it passive parts in the amp. The most recent episode was 90 days ago. I retubed withe MQ from Chris J when I had the amp repaired (locally). So far so good, but I am getting nervous (and broke).

Chris J would like me to consider the Tung Sol KT-120. He told me that the KT-120s are more reliable, the power transformer of the SFM-160 has more than ample current reserve to handle the 0.8 A increase in filament current draw and the KT-120s can take the punishment the SFM-160 delivers.

However, though still very premature, I have received mixed and even a few negative comments on this tube.

Any comments on the KT-120? Other quality options for 6550/KT-88 amps?

Thanks.

Flyfish2002, First, consider that the KT120 has only just recently hit the market. Other than its rating there is little to substantiate a recommendation for 'reliability'. But, the spec's are impressive and I can understand why Chris would recommend them as an alternative.

FWIW, I have some SFM's in my attic which I purchased used. The previous owner had problems with tubes in it (he was using KT88's not know for stability) and gave up out of frustration. I used SED 6550's - had no problems until I plugged in a 'rugged' KT88 and one went and took out a cathode resistor. I had it repaired and recapped - after which I lost one of my SED 6550's in one. Now they just sits in the 'attic' - I need neither the power nor the hassle of hauling it to the techie.

I'm not dis'ing these amps, they sound fine, its just that they were designed around a very rugged tube (EI KT99), which haven't been available for a long time, that could handle the very high plate voltage of these amps (650 as I recall - read your manual for exact specs).

FWIW.

Thanks, Newbee. I am not ready to throw in the towel just yet. These are well-built amps that with Chris' top end mod provide me with alot of enjoyment. I like the SF house sound and am on the hunt for a cream puff pair of Power 3s - fully balanced and no issues with over running tubes.

sound-wise they were great but my matched quad from Jim McShane went south on me in 4 mos. (wouldn't hold bias in both channels) normally i get about a year out of a quad of EH's before they lose their sparkle. i won't buy the gold lions again. i think i'll try the shuggie's from Mr. Deal next...the cheap ones...350 is out of my league

Pehare,

What is a "shuggie" from Mr. Deal?

So the GL KT-88 just didn't hold up for you as you would have expected - 4 mos is crazy. Jim McShane is purportedly one of the "good guys" in tube audio. Did you communicate back to him?

Brent