Need Kt88s Genelex? or Shuguang?

Newbee, good points. The midrange is currently on target with my preferences - lush and detailed. I'm looking for more mid and upper bass definition, more lower bass impact and more extended (sparkling?) highs.
The McIntosh-branded Electro Harmonix tubes that came stock with the 275 were nothing special and developed the "blue pulsating glow of death" after less than 500 hours. So, durability is an issue.

The reissue KT88 Gold Lions may be just the ticket for you. I've read about the reliability issues. Sonically, as they have been described to me, they may be just the ticket. May be. I've not heard them in your amp. I would suggest that you would want to buy them from someone who carefully screens/tests the product and will stand behind them. In that regard, look up Jim McShane - he posts on Audio Asylum and has an outstanding reputation. He also has a history and you might discuss your situation with him before any purchase. Good luck........

I'm extremely happy with the KT-88 Genelex Gold Lion reissue. I've had them for about 6 months. They're great tubes, top to bottom. My amp is a Music Reference RM-200. Solid bass, mellifluous midrange, excellent on up, very nice all around. They're a big step up from the stock tubes (branded RAM but I believe they were fairly generic chinese tubes). I don't think you can go wrong with them. Jim McShane is a good guy, btw, and knows his tubes. Triode Electronics. Or any number of places sell factory matched quads. Jim McS's matching may be more precise than the factory matching.

Hi,

I also have 2 Mac's 275's and I have heard form members here that the PentaLabs/Shuguang KT88SC's are quite good. I am changing my 12ax7's and 12at7 first beofe I change the 88's but I may go with the PantaLabs or GL's.

Rick

I purchased a Shuguang 502B integrated amplifier from Pacific Valve. It comes equipped with Shuguang KT88-98 power tubes. After upgrading the coupling caps and beefing up the power supply it really put out some good sound but, I noticed a loss of resolution at the high frequencies. At a friends suggestion I replaced the KT88-98 tubes with the Genelex Golden Lion Rebuilds. This cleared up the high frequency response beautifully. I recommend spending a few extra bucks and buying the tubes from a dealer who actually matches them. However, I don't recommend buying anything from Pacific Valve. They misrepresented the features of the amplifier.