Almost 3 weeks ago my WBA HPA-03 Reference arrived.Yes, the production took a month, the guy builds them on order....
After unpacking, my first move was to connect it to the line out of my Sonneteer amp and switch power on. The next step was selecting a number of bass-heavy songs on "Anouk is alive", a great live rock cd, and connect my AKG K-400.
And than let it play... a few hours at low volume, the next few hours at medium volume and about 24 hours at high volume. This should be enough, I thought, for the "resurrection" of the K-400, bought in 1994 but still as new, not more then 20 hours and not used for at least 13 years.
The White Bird tubes also got used to labour life this way... 
And now... how does it sound after a few weeks? Who says K-400's have no bass? A serious, solid and tight fundament, clear and open mids and great airy highs without harshness (OTL amp...?) The soundstage is also pretty good.
Music just "flows". It is fun when it is to be fun and intimate when it is supposed to sound intimate.
This combination sounds great, mainly with my favorite menu: jazz. Extremely musical, fluid, lifelike. Listening to "Jazz at the Pawnshop" (vinyl) I just got shivers... Sara K, Norah Jones: stunning!
This AKG handles classical music well, it doesn't get lost in complex big orchestral works. Rock sounded surprisingly fullbodied and controlled. With BASS...!!!
The old K-400, fed by an unexpensive OTL just sings and is in my view a real stunner!
Edited by AnalogEars - 4/5/11 at 4:25pm