I do some rolling with my Audio Research LS5 Mk II preamp.
This unit runs on ten (!) 6922 / E88CC tubes. The first and second gain stages use 4 tubes each. The cathode follower stage uses 2 tubes.
When I first got the LS5, it came with steel pin JJ Teslas. After that I tried German-made Audio Research NOS from the 1980s. Nice improvement. In its latest configuration I am using Siemens 7308/ E188CC tubes in the first stage and Amperex military grade 7308/ /E188CC tubes in the second stage and the cathode follower. This last set of ten tubes set me back over $500 and that was a great deal.
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