today i was messing around with my amp (traynor)when it was plugged into the variac. as i was holding my guitar, i reached for the variac to move the dial, and my finger brushed the variac chassis...i got a good tingle. so i got the MM out, and tried the amp chassis direct to the variac chassis- full voltage! the voltage measurements change in step with the variac dial, too...
then i flipped the "ground" switch that is on the back of the amp, and tried another measurement. this appeared to bring the voltage down into the millivolt range. it also made the amp a tiny bit quieter.
so, should i always leave the "ground" toggle in the up position? should i consider removing the ground toggle? as far as i know the outlet is wired correctly. the amp is from '74 and has a 3-prong plug.
i am thankful that i didn't grab the amp chassis and the variac at the same time or i guess i would have gotten 120v right across the chest; wonder what kind of current could travel through that path?
and i'm one of these people with clammy sweaty hands, so someday i'm gonna get a ripper if i keep playing around with these old amps