Re-tubing my ARC reference 1 preamp

What type of tube are talking about? 6922?

Sorry Yes, it has the 6922 tubes, it has 4 tubes per channel.

I've not listened to the Ref 1. But, FWIW, the two tubes I loved in my SP10II but which, unfortunately, were not rugged enuf to survive, were Amperex Bugleboys and EI6922's. The former are a tad pricy now and the latter kind of hard to find. I'd probably go with the Amperex.

Something else to check out also. In my pre-amp only the front two tubes are critical noise wise. The last two positions are not noise sensitive so you can get a lower grade of tube and save some money. I've never played mix and match but that is a possibility.

Oh, FWIW, I've been using 6h23eb in the line stage of my SP10 - they are, esentially NOS Sovtek's - maybe a tad warmer but not much, but much better tonally than the new production Sovteks.

For "warm" versions of the 6922 type you might want to consider some NOS Mullards, probably the warmest of the lot, next in warmth would be Amperex. I think the Siemens and Telefunken tend to be the most neutral and linear. I agree about the 6H23 which you can get from Upscale Audio, they did sound better to me the current production Sovtek, and they are not too expensive.