Quite frankly, your desire to have a preamp that sounds less "muddy" than the CAP150, uses tubes, and costs less than $1000 might be one of those situations where you can "pick 2 of those 3 things".
Aside from the Quicksilver mentioned above, there are very few tube preamps that might not sound "muddy" to you relative to the Classe. A Marsh P2000t might work for you at around $600 used. (It was a steal even for its list price, IMHO.)
You might actually do better with solid state in that price range, such as a Classe DR5 or Musical Fidelity A3cr.
Better yet, though, you might be best off selling the integrated and getting a different integrated amp. Maybe a used Electrocompaniet or Plinius, for example.
That's probably what I would do with my money, as I feel it would be the best bang for the buck upgrade towards your stated goal.
Michael
Aside from the Quicksilver mentioned above, there are very few tube preamps that might not sound "muddy" to you relative to the Classe. A Marsh P2000t might work for you at around $600 used. (It was a steal even for its list price, IMHO.)
You might actually do better with solid state in that price range, such as a Classe DR5 or Musical Fidelity A3cr.
Better yet, though, you might be best off selling the integrated and getting a different integrated amp. Maybe a used Electrocompaniet or Plinius, for example.
That's probably what I would do with my money, as I feel it would be the best bang for the buck upgrade towards your stated goal.
Michael