The left front side of my Ayre AX-7e integrated amplifier states it is the Evolution model. Unfortunately, it is too difficult for me to look at the back panel (too many wires to pull). If needed, I suggest you call Ayre and ask them. Many people believe the AX-7e sounds better when using balanced connections (XLR) instead of unbalanced ones (RCA).
The article below describes the differences between the AX-7 and the AX-7e amplifers.
http://www.stereophile.com/content/ayre-ax-7-integrated-amplifier-wes-phillips-march-2008
The article below describes the differences between the AX-7 and the AX-7e amplifers.
http://www.stereophile.com/content/ayre-ax-7-integrated-amplifier-wes-phillips-march-2008