Nice! What tube did you put in... and what did it replace... So many of the 12AU7 varieties, and they, most all, sound different enough to make a choice.

Careful! If that bug grabs you, you could end up like some of us with lots and lots of tubes, seeking the great synergy in our different systems and environments! In my main system, there are 5 tube types in the amp, three in the CSP3, one in the DAC, and one in the Zstage. Each matter enough to notably change the whole. But also, having been tuning this system for a long time, I have a really nice, sort of tried and true baseline to work from.

From there, I don't "need" to adjust tubes, but I really enjoy changing up the sound a little... in the grand quest for ever developing refinements toward letting the music be more alive and musical across recordings.... But as much, playing with relatively subtle variations on the long developed sonic theme, a nice tube change gives a different window into the music, waking up a different experience and stimulating hearing/feeling more into the music.

My pretty heavily modified Zstage lets tubes show really transparently and musically, modifications potentially similar to tube refinement in terms of shaping the resolution, speeds and tonal tendencies. And though I like to adjust the broader tube set in different positions, I guess the Zstage and DAC probably get their tubes changed more than anything else these days for me... All else pretty solidly tuned, just nice places to adjust the whole with different characters of quality tubes I prefer, some more resolved, fast, dynamic, and clear; some tending bigger and warmer, but still highly resolved and fastish; and all in between.

I love what tubes can do in my systems!