GT KT66 from Guitar Center anyone?

[Weegie]

My 2466 has started to develop, for lack of a better word, a "HUM". Actually a bit more of a buzz, than 60Hz electrical hum. Anyway, I'm thinking its a bad power tube (please weigh in if you think otherwise), I'm on a budget and Guitar center has GT brand KT66 quad for $139. Has anyone tried these? Also, they have 3 levels of tube. Not sure what that's all about. Thanks

[Wildone]

I won't buy any tubes anymore from ebay or a retailer unless I know that they are tested for microphonics and matched. I have been burned to many times trying to save a few bucks. I have a local hi-fi repair guy I buy from now that can test them and give me what I need.

[ryanmichael95]

The Tube Store..... http://www.thetubestore.com .....Shuguangs, tested and perfectly matched, $100.00 U.S. before shipping for a quad. Buy from a reputable vendor, IMHO Groove Tubes is not, and they are grossly overpriced.