Tubes 101

I have been switching between some svetlanna 6550's and electro harmonix el88's. I prefer the el88's bass and highs. The svetlanna 6550's can make some vocals sound really nice, and possibly image better, but they make some rock music sound awful.

My input tubes are a mix of g.e. and others with no names... I have the regular input tubes that came with the prima luna but prefer these others.

I'm thinking that some bugle boy input tubes with some golden lion kt88's might be good...

Ultimately, I'd like extension at both ends; sparkling highs, tight bass and good imaging are probably my priorities.

B limo
I have SED 6550 and KT88's. Not sure how close the Svetlana sounds compared to SED. But from what you are describing I would suggest Ei KT90's (type 2 or 3). Besides great extension at both ends it has great mids too not to mention a huge soundstage. They are a little pricey but nothing like original vintage 6550's or KT88's. I also have no experience with EH but a local tube seller prefers the Ei KT90 over the Eh KT90 by a long shot. Finding Ei KT90's can be a little difficult since production was halted in the early 90's. Ending in a few hrs - no affiliation
http://app.audiogon.com/listings/tubes-kt90-ei-nos-amazing-sound-kt-version-ei-kt90-second-generation-quad-2-spares-new-in-2014-01-04-accessories-33441-deerfield-beach-fl

Ei KT90 Type II is wonderful. However, I advise you to avoid Type III which is unreliable junk that may destroy your amp, start a house fire, etc.

Jburidan - Per Jim McShane (one of two local tube sellers) the type 3 is a wonderful tube as long as you didn't get the last from the factory. The last ones had mis-aligned heaters which caused the anodes to get cherry red (typically in a few hrs) before arcing over resulting in premature failures. Probably not many left. I have 2 quads of type3 and 3 quads of type2. Except for the type3's being slightly lighter (thinner glass) and the lack of spot welds on the anodes they sound the same to me.

So I do agree there may be a handful of bad type3's still out there there are a lot more good ones left. The type1's were the worst by far.

Thank you! I will research them today, as I am snowed in and listening to some music.

Any oppinions on input tubes?

Btw, I'm still absolutely loving this switch. It has resparked my interest in audio equipment, but more importantly, my interest in music. The combination of this amp and my current speakers that use seas excel drivers has been enlightening. What a revelation when the music starts to make more sense because of the nuances, timing and dynamic swings that are present now.