Amplifier Power tubes - important to sound?


i replaced all the small tubes on my mono amplifiers and now I'm left with replacing the stock Power tubes, kt88.

I like what I hear with 12 new small tubes - telefunken nos 12ax7 and 12at7. 

Now I am left with replacing 16 kt88 stock JJ tubes.   will Probably use Siemens 6550 nos.

How much will this impact what I hear do you think?  I recall hearing that power tubes don't make that much of a difference.

 

emergingsoul

I’ve always found power tubes more important to shaping the sound in ways that are meaningful to me. Small tubes can also be important to be sure, but a lot of times it’s an initial "wow!" impression, then over time I either tire of that variant or just want to hear a different flavor. I listen loud (more strain on power tubes), so perhaps that explains my findings.

With power tubes, my initial impressions tend to stick. The change from a KT88 to KT120 is especially significant in amps where I’ve tried this swap. Anyways, what’s your tube amp that has 16 freaking KT88 slots to replace with a non-existent Siemens 6550? (I know op won’t answer) To be fair, if the Siemens 6550 did exist, I’d prefer it over JJ.

I actually have a pair of VAC Master 300 that use 16 KT88 (plus 8 6SN7), and even with auto bias it’s a kind of a PITA to swap. The KT120 sound great here, too.

@mulveling 

Yes I am looking for siemens 6550. It does look elusive.  And will have to revisit the source of recommendation whom is very good at what he does. I like to biamp so I'm using MC 901 monos from McIntosh.  I like them a lot and they blend tube and solid state very nicely.

I do like VAC quite a bit and still think about it. 

I did a lot of rolling on this class tube, kt88, kt66, 6L6, 7581a, 807A, russian tubes I don't remember the number of,  and they all sounded different.  It seems invariably I liked the new sound (human nature) at first but after going thorugh perhaps a dozen sets of tubes, I ended up back at the tube that the maker (Decware, Steve Deckert) had designed the amp around.  Makes sense really.

Jerry