I think Madfloyd already summed up a lot of my thoughts on the sound differences between the XA30.5 and MA-1's, so there really isn't much more for me to add on that front. Simply put, the system lost a good deal of its "magic" when the MA-1's were taken out and replaced by the XA30.5. For the majority of my listening, I didn't see the meter move on the XA30.5, so I don't think it was running out of gas or being pushed out of Class A mode. As such, I don't think it was an "unfair" comparison with the MA-1's.
While Tvad is certainly entitled to his opinion (and I do respect his opinion) I am in full agreement with Madfloyd in
that we both heard so much of the Pass sound of his XA100.5's when the XA30.5 was put into my system. While Madfloyd would have no issue with bringing his amps over to my place, I did indeed tell him that I didn't think it was necessary. Maybe one day I will take him up on the offer, but for now my curiosity has been satisfied.
Getting back the to the Atma-Sphere amps...I don't think the improvement of the MA-1's over the M-60's is so much about the extra watts, as it is about the ability to work better with a 4 ohm load. With the M-60's, I felt that I had to use the Speltz Autoformers with the 5A's to sound their best, while the MA-1's didn't require them.
I plan on talking to Ralph next week about upgrading my MA-1's to Mk 3.1 status (from Mk 3) and will ask him his thoughts on this subject.
George