New to the tube world

I just bought a BAT VK 75 amp. This amp came
with 6-red base RCA 5692 and 2-Mullard ecc-34
tubes. I would like to know where to to find
back up tubes.These tubes aren't stock but do
make the amp sound better.(to my aers at least)
Where do I start? Thanks

Kevin Deal at Upscale Audio. Great person to conduct business with and extemely knowledgeable about tubes.

Enjoy your BAT!!!! or
Dont' bother with Upscale - unless you bought your BAT piece there, they won't sell any decent 6SN7s to you. (just their policy.) the Red Base 5962 are pretty sought after, though a lot of people dont' think they are the best of the 6SN7 types. Also, the ECC34 are not really a direct 6SN7 substitute - I'd check with BAT on those... if they work - great, but be aware there are differences, electrically, between 6SN7 and ECC34...(I think CV1988 is more the direct mullard substitute for 6SN7). Have fun, tube rolling can be one of the best parts of owning tube gear.

I really don't think you need to find or buy any back-up tubes. The RCA 5692 rated at 10,000 hours. I don't think you can outlast them. They are not output tubes and they will last a long long time.
My best advise is to sit back, relax and listen to some good music...........
I have had good luck with Triode Electronics,, and Radio Electronics Supply,
A fellow named Bill Bittle, who does a lot of HH Scott restoration for me, recommended both of these.
Hope that helps.
You might try Andy Bauman/Vintage tube services or Advantage tube service.Andy is in Michigan,Advantage in Florida.Good luck! Tom