Preamp Deal of the Century

A slight change of tack, but important(at least to me).
Have bought about half a dozen pairs of nos 6SN7s.
Two sets of CBS Hytrons - both pairs have a noisy one in the pair and are slightly different so can't make a good pair.
One pair of Sylvanias that were nice till one 'gave up' - loss of one channel and a gentle @rushing'noise thru one speaker.
Another set of Slyvananias, one dead on arrival, installed the replacement(when it arrived) and within 10 minutes, a bang, a high pitched scream followed by a very frightening, extremely loud & getting louder by the second noise thru the right speaker.
I was very glad I was sitting near the power amp and able to dive over & switch it off !
I now have 6 really nice single 6SN7s , CBS Hytrons, rca and a 3 different Sylvanias - none of which are exactly the same type so can't make decent quiet pair.
Using cheapo Valve Arts which are at least quiet and seem dependable but not the cat's whiskers soundwise.
What worries me more is what damage will a tube letting go do to my system ??
Sorry for my ignorance but I'm fairly new to tubes.
I had to buy a passive radiator for my Virgos and hate to think what a tweeter and mid unti would cost.
I'm tempted just to go for a pair of new Electro Harmonix and hope for the best.
Thanks in advance,
Simon

Simon, IMO it's important to know who you are buying tubes from. Many of the NOS tubes for sale are 30-50 years old and their history/storage/handling is critical. I have a vendor whom I trust because all of the tubes are tested and guaranteed. That being said, I probably have paid a few (actually more than a few) dollars more than I could have but peace of mind is worth it to me. You know the old penny wise dollar foolish thing. I don't need the repair bills and/or down time because I saved $10 on a pair of tubes.
Two things I would do are ask Mick about the specific tube you want to use and then find a reputable vendor who will back his product.

Hi Gang. Mustang... Ahmen and well said! Lugnut... "you got mail".....Simon....If you can ascertain the vintages of the good singles you have I would most likely have a mate for any one of them. Feel free to email me. Just catching up on the thread here as I recently experienced a full scale computer crash, I am a certified knucklehead with these damned computers. AHHHHHH!. For those without a tube tester or do not have a trusted source for nos tubes.... the EH 6sn7 is a very synergistic tube for line gain in the supratek's and really a no brainer. I have been running in a pair in my Syrah [about 40+ hours] and am more than a little suprised at how good they really work in the curcuit, they sound considerably better after the 24 hour mark. Gotta go now.. cheers

Hi Guys, thanks for that. I didn't exactly skimp on the price of some of tubes.I have had a few free replacements but not much luck with these either.
I kind of get the impression that a good set of readings can be fairly meaningless unless someone actually listens to the tubes?
No one tried to rip me of, the tubes were all tested, how well I'm not sure. It just gets tedious putting in new tubes which sound lovely, only to find one is usually too noisy to be bearable or else tries to kill my speakers.
I'm thinking of doing a bit sculpture/artwork along the lines of the NOS tubes graveyard, should look quite cool !
Simon

Simon, FWIW the Sylvania 1958 6SN7WGT Chrome Top is a killer tube. One of my favs. Good luck.