about (TYPE J) AC power plugs

[nylon]

tanong ko lang po, ano ang advantage at disadvantage ng may ground plug ang power plug sa walang ground plug, yung pangatlong plug? Type J yata ang tawag dun sa plug na ganun db usually pinuputol natin ito para magkasya sa standard wall socket natin yung power plug factor ba ito para malessen o mawala ang hum ng amp?

ganito po yung itsura ng plug

http://www.kelseyweb.co.uk/site/m6/tech/World_Power/image/J%20plug.jpg

[sl1200ltd]

read this...  
http://talk.philmusic.com/board/index.php/topic,201951.0.html

http://www.prosoundweb.com/article/stopping_hums_buzzes_and_shocks_on_stage_part_1_volts/

[nylon]

thanks sir