Tube recommendation for Audio Research LS-2b?

The Chinese 6DJ8 drew a bit more heater current then the standard Russian 6922 if my memory serves me. So a different value resistor was used for the Chinese tube. The Chinese tube was stock at the time that preamp was manufactured.

I switched my LS2B to a Mullard Gold Pin and it sounded great.

I had an LS 2b. Have a LS 5b as a backup pre

You really need warm tubes for the LS2

nos telefunkens,mullards and amperex from the sixties worked like a charm for me

I own also a ls22 and i measured that my EI ecc88 have a fillament
current togheter of 1.6A[incl.relay circuit].that is already to high for 1.5A max.LM317!For example a 7308 have more current than that.

I had the LS2 a number of years ago, and it definitely needed the warmth and slightly softened highs provided by Amperex Bugle Boys. The BB tubes were also very dynamic. In contrast the tubes I bought from ARC, a Chinese 6DJ8 and a Sovtek 6922, were coarse, grainy and lacking in refinement.