I nearly killed myself playing with tubes in the early 90s. The 6.3v heater circuit got a short in the transformer winding and delivered a rather painful 220v b

I nearly killed myself playing with tubes in the early 90s. The 6.3v heater circuit got a short in the transformer winding and delivered a rather painful 220v between one hand and the other, through the table to earth. Was in hospital for 3 days with arythmia after being knocked out cold for about 5 minutes. Still they are one of the coolest devices ever :) I just have a lot more respect for them and mains now.