03-10-11: MagfanNot expensive at all. I have this one (not in my audio system), which I once had occasion to use experimentally. Only $119. Just one problem, though -- it is absurdly noisy every time it decides to run the motor, which was every few minutes at my location.
It would be wacky expensive, but couldn't a motor driven Variac be used to automatically control output voltage to 120, or whatever desired?
Best regards,
-- Al