WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
Same tube amp :
House 1 neutral- phase 230v -ground
no noise ultra clean less than 1mv A.c. residual
House 2 two phase without neutral phase 115v phase 115v - ground. Very noise 10mv residual noise,
On 97db speakers.
