PS Audio BHK lacking..


I bought a used PS Audio BHK preamp to replace my Rotel.  It sounds thin with no depth & bass compared to my Rotel so I let it run for over an hour with no change. I'm new to tubes so I'm looking for ideas. New tubes or what?
128x128fertguy
Next is what should I expect to pay. There is a set of Telefunken 12au7 on line, new for $400.
What kind of qualities do you enjoy most in your music and what music do you play most often?  Easier to recommend tubes knowing what you like....warmth, speed, soundstage, strong bass, lots of air, treble sparkle, etc...
I’d go with strong bass, soundstage & air.  Mostly old rock, country, & now classical because it is well recorded.
It should be better than a Rotel, I had the 250 for about 2 days and returned it.  In all fairness, I did purchase it used from The Music Room.  No problems returning.  It just is underpowered.  I had sold an old Adcom 555ii which would beat it hands down, no tubes too, and sounded sweeter.  I like PS Audio's marketing and return policy and the people - but the stuff is not high end in my opinion - right in there with MAC and Rotel.