best for 6sl7 and 6sn7 tube nos?

My Integrated Preamp/Amp uses a pair of 6sl7 and 6sn7. 1st time I ever had these types. Cayin A88T. I love it's sound.

Which specific tubes?

Factory tubes sounded great (no identification of tube maker).

I blew one (put in wrong socket). I put a spare GE I had in a drawer, sounded great. Then bought a new matched pair, they sounded bad. Switched them for a different brand, half the price, they sound wonderful just like the original's.

There is no best, and the arguments about these types are endless and can be found elsewhere on the internet. Again, check Tubes Asylum to start.

I am a believer in NOS tubes, but I don't have experience with those.  Call Brent Jessee or Andy Bouwman of Vintage Tube Services and they'll help you get the right tubes.

Andy at Vintage Tube Services is my go 2 expert…..and he has killer test gear….

Andy at Vintage Tube Services is my go 2 expert…..and he has killer test gear…

      Agreed!