Problems getting the best out of my Berning

Hello fellow Agoners,

I beckon for help from experienced users of the Berning ZH270! I just received mine new a week ago, and although it is an incredible amp, it is not meeting my expectations. HELP!

First the good news:

This is the fastest amp I have ever head, and it has virtually no noise floor. I am truly impressed with these aspects. It handles most everything with ease and clarity.

Now my system:

Proac 2.5 loudspeakers
Cary CD308 and Arcam FMJ CD23
Kimber PBJ Interconnnects
Audioquest Type 4 cables

(I've also used Dynaudio Audience 72's and all MIT cables, and Triangle Titus + Audioquest Slate cables and PBJ IC's).

OK - now to the problem:

On all three setups mentioned above, the amp seems strongly biased towards the midrange and upper midrange, resulting in a fatiguing presention. There is a significant decrease in bass (not detail, but the actual movement of air) from the other amps I have used for comparison (Classe CAP 101, Pass Aleph 3, Adcom GFA 5400). While the detail and fastness are truly amazing, the midrange emphasis is getting the worst of me!

I've spoken with David Berning and Frank S (FS Audio.com) and both encourage some tweaking to get rid of this perceived (psycho?) acoustic bias. Frank is going to send me some interconnects to try. David mentioned that others have changed the tubes. He doubts anything is wrong with the amp.

Is this all in my head, or have others had similar problems and needed to make adjustments to get it right? While all my other amps are currently SS, I have trouble believing that this is the "tube sound" (I've heard other tube amps). Other threads mention system tweaking to get rid of a "glare" with the ZH270, changing tubes, sensitivity to cabling. My perception of the sound is pretty strong - currently I like my Aleph 3 a whole lot more with the existing setup.

I'm willing to put some time and money into making this work - because in all other respects, this is an absolutely amazing amp. Perhaps it doesn't suit my ear - but I want the advantages of this amp without the disadvantages I just mentioned. Please - suggestions on what to do from all you experienced Berning fans... so many high commendations cannot be that far off (right?).