Tubes 101

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.

B_limo don't get too ahead of yourself swapping tubes. For any advice to be meaningful you need to know what you want to change the sound to with your current tubes. Looks like the PL5 comes with Gold Lion KT88's for outputs. But what brand are the 12ax7's and 12au7's? Also the PL5 is autobiasing so another word of caution before swapping output tubes. You want to get matched quads. Unlike manual biasing the autobias has a tighter window for biasing.

Where are you that you are snowed in?