Lamm L2 Reference tube recommendation

I rolled some RCA 12AX3 in place of the stock Sylvania 12AX3. I thought I detected a slightly more natural presentation with less grain, but I could be fantasizing. The difference was not profound by any means. Nothing like what I experienced when I installed Mullard tubes in the LL2 Deluxe in place of the stock tubes.

The thing is there is swapping signal tubes and swapping power supply tubes. The LL2 is a tubed pre with a tubed signal path. The L1 and L2 are solid state with tubed power supplies. So in a well designed circuit, there is less of a difference with swapping tubes in the ps.
But in my case with the L1, the difference was easy to identify albeit small.

Nutella, would you discuss which tubes you prefer and why?

I am trying to eliminate as much grain as possible.

I realized after rereading Rodman9999's post that I installed an RCA 5651A rather than a 5651.

I dont think you'll find much improvement tube rolling with the L2. The most important thing is to check the voltage output of the power supply as specified in the manual. Slight deviations, usually loss in power will make it sound dark and veiled. Unfortunately I found myself making this adjustment weekly and replacing the tube monthly making it too high maintenance for my taste.

Between the RCA and Raytheon, I prefer the Raytheon. It is just slightly more natural in its presentation. The difference is small.