According to Stereophile measurements...
I assume the other amps in the XA.5 series will be similar in this respect, but I don't know that for sure.
Bryon
While the XA30.5 may give 30Wpc into 8 ohms in class-A (14.8dBW)...the amplifier doesn't actually clip (defined as the THD reaching 1%) until a much higher power level: 130Wpc into 8 ohms (21.14dBW). Even higher powers were available into lower impedances before clipping: 195Wpc into 4 ohms with both channels driven (19.9dBW), and 332W into 2 ohms with one channel driven (19.2dBW).
I assume the other amps in the XA.5 series will be similar in this respect, but I don't know that for sure.
Bryon