Pass X150.5 vs. X250.5

Ccanino,

Have you assessed your power delivery? I owned an X150.5,
and it drove my Avalon Avatars to acceptable levels on music. It did sound somewhat worse when I drove it very loud. I decided that the (1) 15 amp breaker servicing my living room wasn't enough.
This is already after I ran a beefy extension cord from the kitchen, and put my front end and Video on that breaker.
I'm planning on dedicated lines, soon..
I have (2) James EMB-1200 subs. I'm only using (1), until my dedicated lines are in.
You may be experiencing dynamic compression, due to lack of power to your system...

Does not seem like an issue that will be solved by going from 150 to 250 watts (not much of a difference in dbs)and I think the 3As are fairly easy to drive and your room is not all that large. Is what you are hearing so apparent that it must be something other than a Class A versus B issue?

Where the meter sits is completely arbitrary, some sit at 12, some sit at 11, others wherever. What matters is if it moves. If it sits and does not move, then there is no leaving Class A. If it bounces all over the place then you need more power. The X250.5 is definitely a jump in power, but as many have pointed out it is doubtful that is your problem, it is most likely something else in the chain. Is the X250.5 a better sounding amp, to me yes, but if you have fatigue it is probably something else.

What is your source?

Acurus makes a very important point and I agree 100%.
What is the location of your volume control knob?
Does your meter move from class A to AB?