Quote:
Originally Posted by nosebleedaudio  Yes you are correct with respect to the 60's grounding; they did not exist back then.
I did not mention the cap being switched because I would NEVER use them with a properly grounded cable/chassis.
One more note about the cap being switch; it can be a very dangerous thing, have seen those caps shorted and then you have a full 120V on the chassis.
The caps can and do leak current into the chassis, and if not bleed off via a real ground you can have 120V on the chassis.
Today with NEW unbalanced 2 prong gear you can simply reverse the AC plug and can change the ground noise, if that is a problem.
It changes the AC phase going to the power transformer which sometimes helps with hum/noise.
The internal grounding is usually floating, since it has no REAL AC ground point, and when the unbalanced signal is plug in to something that IS grounded is uses THAT for its ground also.
Hope this makes sense |
Let's deduce what we are actually dealing with.
a 0.05µf cap has a capacitive reactance ( i.e. impedance) of 53K at 60 cps..
This cap will flow 2.2milliamps of current. Not enough to hurt you but will give you that instant reminder that the 'ground' switch is in the wrong position!
You can still use this when employing a 3 wire plug, as it *willl* reduce RF and other A.C. induced noises....