05-09-10: KeithrThat's a good point. Certainly worth checking with Zu Audio, but be certain to tell them specifically which amp is being used.
you might ask Zu (Sean) to make sure the impedance is correct for OTLs---as I recall, you can have this adjusted at the factory.
As I recall from a dealer who once sold Zu Audio and still sells Atma-Sphere, the tweaked Zu impedance was more important for use with an Atma-Sphere S-30 amplifier. The output impedance of the M-60 amps is lower than the S-30.

