Quote Originally Posted by Steve Smith View Post
Isn't the 220v supply actually closer to 208v derived from connecting across two of the three phases rather than one phase to neutral?


Steve.
120, and 220 are just nominal values. Folks in the USA that are more hard core into guitar amp building and guitar tone than myself run a variac to set the voltatge. My workshop measures 117V with my RMS meter most of the time and I'm fine with that.

Here is Robben Fords rig. Notice the red Variac!