Stupid dangerous post, disregards *all* Electrical Safety rules valid anywhere.In most cases the voltages aren't lethal. They're definitely dangerous, but I've been hit a few times with 350-450vdc and it leaves a nasty mark, but I'm not posting from beyond the grave here. The lethality is overstated in mostguitar amps, as they tend to sit below 500vdc on the power supply. Old Ampegs, Musicman RP100's, Marshall Majors, etc on the other hand will hurt you badly and likely land you in the hospital.
Voltages greater than 50 V applied across dry unbroken human skin can cause heart fibrillation if they produce electric currents in body tissues that happen to pass through the chest area
Living human tissue can be protected from damage by the insulating characteristics of dry skin up to around 50 volts. If the same skin becomes wet, if there are wounds, or if the voltage is applied to electrodes that penetrate the skin, then even voltage sources below 40 V can be lethal. Accidental contact with high voltage supplying sufficient energy may result in severe injury or death. This can occur as a person's body provides a path for current flow, causing tissue damage and heart failure.