Amplifier Power tubes - important to sound?

@jasonbourne71 They make adapters.  Very common. 

@jasonbourne71 I’m sorry, what are you talking about? It’s very easy to substitute an 807 for a 6L6 or KT66 with an adapter socket you can buy on eBay. You just have to be careful to observe the lower dissipation rating and keep the plate and screen voltages at 400VDC or below. The 807 is pretty much a 6L6GB with slightly higher max ratings. My amps will accomodate KT66, 6L6GC, 5881 or 807. And the 807 uses a *five* pin socket. The 1625, the 12 volt version of the 807, uses a seven-pin socket.

All…please be very diligent and extremely careful recommending tubes for OP’s system. The tubes must be on a good enough level to not embarrass the amps that will be driving a $50,000 pair of speakers that OP is looking to purchase. Please continue your battle on tube choices, plate voltages, tops, compatibility , requirements and adapters. I’m sure all this information will be extremely helpful to @emergingsoul 

And just curious, @emergingsoul , with you being so impressed with Jay’s Audio Lab, are you contacting him for an advice. What did Jay say about your setup and future plans?

@brownred6 -

        The Svetlana Winged 'C' tubes were a very nice tube and I hated to see the company shut down after the St Petersburg plant burned, with all it's equipment.

        If you do manage to find any remaining stock; there's a 99% chance, they'll be factory seconds, as all the first quality tubes went years ago.