Rocky,
While I don't know of any places to listen to the Yam/Zu combo, there are places in the Bay Area to listen to SETs and high efficiency speakers.
There are several dealers in the area that have SET amps.
try Pitch Perfect Audio in SF, Taurus Tube audio in Newark, and Witch Doctor Audio in Oakland.
You should be able to get a feel for the SET sound.
Also, the Bay Area Audiophile Society is having some kind of Zu demo in October.
While I don't know of any places to listen to the Yam/Zu combo, there are places in the Bay Area to listen to SETs and high efficiency speakers.
There are several dealers in the area that have SET amps.
try Pitch Perfect Audio in SF, Taurus Tube audio in Newark, and Witch Doctor Audio in Oakland.
You should be able to get a feel for the SET sound.
Also, the Bay Area Audiophile Society is having some kind of Zu demo in October.