Total number of people killed from home stereo, TV etc. is about 3 per year.
www.cpsc.gov/library/shock95.pdf
Chance of 1 in 100 million is not big but remember that ones who died had most likely something wrong with the wiring or grounding. What percentage of people have wrong grounding? Most of people buy equipment and don't modify it or use cheater plugs. Let say that one percent has wrong wiring or no grounding. Now your chances of fatal accident got 100 times higher - 1 in a million. Take into account that it is amount per year and we like to be alive for, let say, next 50 years - now your chance is 1 in 20 thousand. It might be still small but you would be ecstatic to play lottery at such odds. Don't play lottery with your life.
I have another problem with this attitude toward safety. I might be ignoring safety here and there, but would never ever tell anybody that it is OK to do so. That would be irresponsible and stupid of me. Would you recommend to your friends modifications to their car braking system claiming that only one car in so many millions have accident from malfunctioning of the brakes? No because it would place them in danger.
As for floating shields - they should be grounded. Non magnetic shield protects from electromagnetic pickup by means of skin effect. It means that current is induced, since non magnetic shield cannot stop it, but travels on the outside - shield because of skin effect. Equivalent field in the center of conductor is zero. Shield has to be grounded for this to work. At lower frequencies skin effect stops working but cable is too short to become effective antenna (below 1/10 of the wavelength).
Switching power supplies generate noise but it is noise at high frequency easier to filter out than 120Hz. For that reason Jeff Rowland uses switching supply in Capri preamp where efficiency is irrelevant. His newest class AB power amp model 625 has 1MHz switcher. It is difficult to say what a switcher is because every linear power supply is switching power supply operating at 120Hz where width of the current spikes is load depended. Properly executed SMPS switches at zero voltage/zero current and can be very quiet but they got bad rap from poorly designed cheap computer supplies. Don't forget that linear supplies are unregulated while SMPS are line and load regulated.
http://jeffrowlandgroup.com/kb/questions.php?questionid=145
www.cpsc.gov/library/shock95.pdf
Chance of 1 in 100 million is not big but remember that ones who died had most likely something wrong with the wiring or grounding. What percentage of people have wrong grounding? Most of people buy equipment and don't modify it or use cheater plugs. Let say that one percent has wrong wiring or no grounding. Now your chances of fatal accident got 100 times higher - 1 in a million. Take into account that it is amount per year and we like to be alive for, let say, next 50 years - now your chance is 1 in 20 thousand. It might be still small but you would be ecstatic to play lottery at such odds. Don't play lottery with your life.
I have another problem with this attitude toward safety. I might be ignoring safety here and there, but would never ever tell anybody that it is OK to do so. That would be irresponsible and stupid of me. Would you recommend to your friends modifications to their car braking system claiming that only one car in so many millions have accident from malfunctioning of the brakes? No because it would place them in danger.
As for floating shields - they should be grounded. Non magnetic shield protects from electromagnetic pickup by means of skin effect. It means that current is induced, since non magnetic shield cannot stop it, but travels on the outside - shield because of skin effect. Equivalent field in the center of conductor is zero. Shield has to be grounded for this to work. At lower frequencies skin effect stops working but cable is too short to become effective antenna (below 1/10 of the wavelength).
Switching power supplies generate noise but it is noise at high frequency easier to filter out than 120Hz. For that reason Jeff Rowland uses switching supply in Capri preamp where efficiency is irrelevant. His newest class AB power amp model 625 has 1MHz switcher. It is difficult to say what a switcher is because every linear power supply is switching power supply operating at 120Hz where width of the current spikes is load depended. Properly executed SMPS switches at zero voltage/zero current and can be very quiet but they got bad rap from poorly designed cheap computer supplies. Don't forget that linear supplies are unregulated while SMPS are line and load regulated.
http://jeffrowlandgroup.com/kb/questions.php?questionid=145