Re-tubing my ARC reference 1 preamp

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.

Slates, on the more affordable front, the 6H23 NOS Russian Military tubes should give you what you're looking for. You can get them from Upscale Audio(get Platinum grade) or if you want the same tubes but the cryo version, the ATSI Advantage Tube Services sells them. Personally, I'd go for a regular version from Upscale. They sounded smoother, more natural with better bass and soundstage than both the Sovteks and the Upscale Audio EH6922 tubes I have. They are reall good tubes for the money.
Very close to the Mullard 6922 tubes I use in my LS-25.
If you want some good NOS tubes like the Mullard or Amperex, you can check out Brent Jessee Recording and Supply.

I recently retubed my ARC Ref.1 with the 6H23's from Upscale and have been very happy. These tubes are quiet with great bass and midrange. I previously used NOS Amperex tubes purchased from ebay with mixed success. Many of them were noisy and produced microphonics. There is no such problem with the 6H23's.

Randy