Genelex Gold Lion KT-88 reissued tubes

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. :)

I have also had problems with Genelex Gold Lion KT-88 thermal runaway causing damage to Jadis JA30. While they worked they sounded great but would not try these again no matter what the sonic benefit.

I also lost a GL reissue KT88 the other night. Heard a humming sound and one of the quad was glowing orange. The quad is less than a year old with about 200 hours on them.

Any tube can go bad any time -- this is not hot news. However, vacuum tubes were once the ONLY electronic valve available -- and for the most part delivered service with the same reliability as transistors -- and, believe it or not, often the same longevity.

Of the modern manufacture power tubes, the reissue Gold Lions, Pentas (Shuguang) and S.E.D. (formerly Svetlana) KT88's all provide remarkable levels of sonic performance, though still short of the best vintage tubes. In terms of reliability, only the Electro Harmonix seemed to have continuing problems. McIntosh recently dropped them in favor of the S.E.D for their OEM KT88.

Of the current manufacture KT88's, only two have the air and sparkle of the vintage Genalex/GEC KT88's from the UK ($800 -- $1400/quad): the E.A.T.'s ($1600/quad) and the new Shuguang Treasure Series Premium Grade ($350/quad -- $650/quad depending who you buy them from). I've not heard the E.A.T.'s but I have the Shuguangs and they equal my NOS Gold Lions sonically. Now let's see how long they last ;--)
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I just replaced my (8)EH KT88's in my Cary 120S amp with 8 Grade A Shuguang Black Treasures and also replaced the 2 driver and 2 input 6sn7's with Shuguang Black Treasure CV181Z's. The amp sounded very good with the EH tubes but the Treasures redefined this little Cary. Every aspect of the audio performance has been elevated to levels I thought were impossible. The tubes have about 90 hours on them and I am told they will improve with more hours. My Preamp is the Cary SLP 03. I have TJ Full Music 12AU7's coming and can't wait to try them out (EH 12AU7 replacements) The speakers are Harbeth Compact 7ES3. After 40 some odd years it seems like just maybe the SEARCH is over. I can honestly say the Shuguang tubes have been the single largest improvement I have ever made in any of my many audio systems over the years. Dave Hubbard