BAT VK-600 vs Pass XA100.5

07-08-10: Madfloyd
Much better (to my ears).

In comparison, the Pass don't control the woofers of my Wilson Sophia 2's as well. The Pass is much warmer sounding and rolled off on top.

It was well established in another post that there was an improper preamp match with the Pass Labs amps in Madfloyd's system. The preamp he used had a very high output impedance of over 2k ohms. Therefore, what he heard in his system was not the fault of the Pass Labs amplifiers, but with a poor impedance match.

I imagine one will be hard pressed to find another person who hears Pass Labs XA-.5 series amps as being rolled off on top and not in control of the bass when the amps are matched with an appropriate preamp (not hard to do).

Sure would like to see your system posted w/some pics!

Tvad- have you heard the VK600 to compare top ends?

impedance mismatch i thought would only be an issue on the bass, not on the top end.

07-09-10: Keithr
Tvad- have you heard the VK600 to compare top ends?

I have not had VK600 in my system.

impedance mismatch i thought would only be an issue on the bass, not on the top end.
Keithr (System | Threads | Answers | This Thread)

Not necessarily. Regardless, has any other owner commented about a rolled-off top end on XA-.5 series amps? I haven't found any, but I'm interested to read comments from XA-.5 owners who have experienced this (along with accompanying equipment).

Tvad, when I compare these two amps, input inpedance had nothing to do with it.

My main SS preamp is an H20 Fire, which has no problem driving the Pass.

My other SS preamp is a Parasound JC-2. I've used many other preamps with the Pass as well, including the Pass XP-20.

When I say 'rolled-off', I mean in comparison to other amps, i.e. the Pass is slightly darker sounding than my Bat, or other amps that I've owned (Theta Citadel 1.5 comes to mind). This is with solid state preamps, NOT tubes.

Yes, I tried a couple tube amps that were not good matches with the Pass (Ref 3, Audio Valve Eklipse), but that hardly means EVERY preamplifier I've tried has been a mismatch.

No amp does everything well. Pass amps are biased towards great midrange and in my humble opinion, aren't the last word in bass control.