The 'Shinpong' post seems to be a random list of phrases, some from engineering text books and some from the writing's of people who don't have a good grasp of electrical theory.
But the major confusion in threads like this one comes from the words 'ground or earth'. These words have several meaning and often it's not at all clear which meaning applies.
Some of the more likely meanings for 'ground/earth' are:
a] a connection or path to Mother Earth.
b] a connection or path (Safety Ground/Protective Earth) to the power company Neutral.
c] a chassis connection to the Safety Ground/Protective Earth conductor.
d] the audio circuit/power supply common.
e] a shield connection to a chassis.
We should note that while all these are galvanically connected, each one has a different task.
We should also note that neither Mother Earth nor a large box will act as a sump or sink for leakage currents or noise currents.
As both leakage currents or noise currents are only interested in getting back to their voltage sources, which in both cases is the power company Neutral.
But the major confusion in threads like this one comes from the words 'ground or earth'. These words have several meaning and often it's not at all clear which meaning applies.
Some of the more likely meanings for 'ground/earth' are:
a] a connection or path to Mother Earth.
b] a connection or path (Safety Ground/Protective Earth) to the power company Neutral.
c] a chassis connection to the Safety Ground/Protective Earth conductor.
d] the audio circuit/power supply common.
e] a shield connection to a chassis.
We should note that while all these are galvanically connected, each one has a different task.
We should also note that neither Mother Earth nor a large box will act as a sump or sink for leakage currents or noise currents.
As both leakage currents or noise currents are only interested in getting back to their voltage sources, which in both cases is the power company Neutral.