@tablejockey
The PL is really a wonderful preamp- and yes I do switch out NOS tubes a lot...I'v been going between Brimar's, Amperex, and Telefunken's- and they do all sound different. The first sound more lush and full, the Amperex more defined in the reproducing the sound stage, and the Telefunken's somewhere in between. I cannot say which sounds better vs the other as it really depends on the source material ; I would probably say the 1st two are my favorite. I have yet to try Mullard's. What I can say is that I just love the whole experience.
I would like to try to upgrade from the PL just to see what a preamp with an upgraded volume control could do vs alps pot. If I where to identify where my system falls short is soundstage depth- it is there but I think it could be significantly deeper- and slightly better soundstage placement. I think this may indeed be related tin part to the volume control and other better internals.
That said, right now I am focusing more on the phono.
After doing a little more research I think the PS Audio for SS is a worthy alternative- with my current phono as a trade in it would be $2k.
As for tube option I am not quite sure which way to go.
And then between the two- SS or tube- I am still pondering. A lot of other members are suggesting the Allnic is the way to go.