KT88 Opinions

Ducati - Talk to the guys at Doug's Tubes. I went from stock Sovtek 6550s to JJ/Tesla KT88s and more recently to Shuguang solid plate KT88s. Both mftrs. KT88s were better sonically than the Sovteks in several ways. Howevere, the Sovteks were ~5 yrs old or so and I'm guessing not even in the league of your Phillips 6550 to start. I really, really liked the JJ/Teslas but they were not too reliable. Compared to the JJ/Teslas, the Shuguangs seem more detailed, with more hi end extension and air. Downside is a bit of harshness on some CDs(but not vinyl) when listening at louder volumes. Good luck with your decision.

Agree with above..Doug's tubes. The Shuguang Kt-88 solid plate( not plate with holes) is very good as are the JJ's..different, but good.. Both better the Sovtek, EH, and Svetlana tubes. I prefer the SED Winged =C= myself.

I went from Sovteks KT-88, came with my recently purchased Quicksilver V-4, to Genalex Gold Lion. This switch had the same sonic effects as when I replaced the EH 6922 with Amperex 6922 U.S. PQ in my CDP, from thin and airy to full, detailed and dynamic!! I bought matched Quads from the TubeDepot they were great to deal with and fast (no affiliation) so far no problems!!

In my MC275 I just replaced my (still good) SEDs with Genalex Gold Lions and there is no comparison. While the SEDs are Very good, the GLs are vastly superior in detail, bass impact and overall dynamics. I cannot recommend them highly enough.

Genalex Gold Lions are used in my MC275s run in mono. Data sheet says two valves in class AB1 gives a continuous output of up to 100W.

I've used the following to retubed my MC275s and C500T:
http://www.dougstubes.com
http://www.musicdirect.com
http://www.tubedepote.com

[url]http://www.tubeworld.com[url/] is another great source.