Pass Labs xa - .5 amps

The Pass Labs XA-30.5 and XA-60.5 don't display the shortcomings in my system that you describe, and since I'm not familiar with your system, room or listening preferences, I can't offer an alternative based on experience.

Just for something to research...I've never heard the amplifier myself...you might do some reading about the new Modwright KWA 150.

Soren,
I have the XA100.5. I used to have the XA160. In my system, Eggleston speakers 87dB/6ohm, the 160s were a little slow/heavy in the bass as you describe. The XA100.5 has much faster, more articulate and defined bass and are better balanced overall. Great control over the woofers. The mids on voice and strings are exceptionally involving - lots of body and presence. I have not heard the XA30.5 or XA60.5. Matching a pre to Pass amps is very important. I auditioned a very well regarded tube preamp which sounded terrible in the bass region with my amps but great in other systems.

It's possible the output impedance of the Accuphase C-275 is too high for the XA-.5 series. This would possibly cause less than optimal bass performance from the Pass Labs amplifier. I couldn't find an impedance spec on the web for the C-275, however. Perhaps the owner's manual lists it.

Hi

The output impedance is 50 Ohms. Is that too high for the XA30.5?

50 ohms should produce excellent bass on the XA-30.5.