Solid state or Tubes preamp phono stage.

Soko, I’m sorry but your summary dismissal of tube phono stages and those who prefer them is ridiculous. One could as well say exactly the same about solid state and those who love it, and be just as pointless. And the parting shot about running hot is equally beside the point. That’s how tubes work, by heating up a filament that then gives off electrons. Class A solid state gear runs hot too.

But the 12BH7 will sound better, by all accounts (see TubeDIY Asylum).  I haven't tried that type myself. Now, if the 12AU7 is being used as a cathode follower, then it does not do so much sonic damage and can probably be tolerated as is. In my own search for the "best" 12AU7, I ended up with genuine Amperex Bugleboys, because I had a few in my stash, purchased new by me in the early 80s. But even those were bested by the 12FQ7.

I agree with Mulveling. 12BH7 is another tube type that is said to be a good sub for the 12AU7, which is to say, an upgrade.

Yogiboy said "5914, 5963,6189 and ECC82 are all replacements for the 12AU7 tube".  ECC82 is definitely only a 12AU7 by another name. In the case of "5914" in Yogi's quote, I think that's a typo and he meant 5814.  The open question is whether 5814 is only yet a third name for a 12AU7, i.e., the same tube with a different alphanumeric code, or actually a different tube electrically that can be freely substituted for a 12AU7/ECC82.  As to the 5963 and 6189, all bets are off so far as I am concerned but one can look up the specs in any good tube manual to see whether they are identical to 12AU7/ECC82.  I'd preferentially go with a 6CG7, provided a 6.3V filament supply and the ability to reconfigure the socket or with the 12FQ7, provided a 12V filament supply, that requires no soldering.  But both of those latter tubes may require a bit more filament current than the 12AU7/ECC82.  Most gear can handle it.  And I feel very strongly that the sound will improve.

Isn’t 5814 a 12AU7 by another name? Anyway, sorry for being so dogmatic but there are actual data to support my view.

The best 12AU7 is no 12AU7.  Replace them with 12FQ7/6FQ7 (depending upon the filament voltage supplied to the socket) or with 6CG7 (which requires a minor re-wiring of the socket for the filament supply only and requires a 6.3V filament supply).  Then you've got something.

The point remains; each of us has to spend the time listening to a variety of components in order to figure out for onesself what constitutes audio Nirvana.  A bunch of opinions from strangers might provide an idea where to start, at best. Sometimes that means you have to spend some money that may take you in the wrong direction.  That's why we have Audiogon and other marketplaces.

Bliss, I wasn’t sure of your meaning. Your statement could have been taken either as a characteristic of the Trumpet or as a blanket characteristic of tube phono stages. Thank you for the clarification.

I take issue with Bliss’s comments on tube phono stages in general, unless he’s referring specifically to the Trumpet, which I’ve never heard. Modern tube phono stages in general are not rolled off and lacking in resolution at all. Tubes inherently produce very low distortion and very wide bandwidth, more than an order of magnitude greater than the audio spectrum. A good designer can make full use of these attributes in a phono stage. In tube amplifiers, the coupling transformer can be blamed for adding harmonic distortion and limiting the frequency response. A good tube phono stage can compete on equal footing with solid state, where lab measurements are concerned, except possibly in SN ratio. So I advise the op to listen for himself.