Hi guy's, I just got off the phone with Peter at Pass Labs so here's the facts regarding the new XA.5 series amps.
Peter shared the following information:
1) The XA.5 series amps will double down as impedance drops, unlike the present XA amps that do not.
2) The sonic signature of the XA.5 series will not qualitatively differ then the present XA amps, but will offer the XA sonics to audiophiles with much more difficult speakers to drive in their systems.
So, if your a present XA amp owner and have no problems driving your speakers, the new XA.5 series really would not offer an advantage sonicly to you. On the other hand if you love the sound of the XA series but did not consider these amps because of the mismatch with your speakers, the XA.5 series would remedy that concern.
Finally, to be as accurate as I can be regarding what Peter shared with me if there is any sonic differences between the XA/XA.5, there should be no difference if impedance does not matter, but it's still "theoretical" because no one has yet directly compared a XA-100 to a XA.5-100. However, what I got out out of the conversation was that I don't think I will be sending in my XA-100's for upgrading in the near future.
