[haarvi]

New Discovery:
I pulled the plug on a headpnone amp I have connected to the same line as the tv.
And the hum stopped.
The headphone amp has a grounded plug.
And when I attached a cheater plug (eliminating the ground connection) and reattached
the amp to the line, the tv hum did not reappear.
So I solved my hum problem.
But I have the headphone amp attached without a ground connection.
Is that a problem?
Also noteworthy is that with the headpone amp connected to the line without the
cheater plug, I would hear hum through the attached headphones.
Until I disconnected the cable to the cable box.
At which point the hum disppeared from the headphones.
As a further peculiarity, I have a second headphone amp connected to the same line,
and this amp, though it has a grounded plug, gives me no hum either to my attached
headphones or to the tv.
I am thinking that the hum problem which appears when the problematic headphone amp
is connected with a grounded plug, but not when it is connected ungrounded, may be an
indicator that there is a problem in the ground wiring on the line.
Any ideas or suggetions?