Operation Manual, RA2400 & RA7300 Power Amplifiers
Page 20
Document # 9301H62800 Ver. 1.00
sequence provided. If proceeding from one step to the next does not eliminate the problem,
contact your installer.
Potential Ground Loops in a Complex A/V (audio visual)
System
Suggestion #1:
To determine if a cable TV connection is responsible for the hum, first turn all components off.
●
Disconnect the cable TV feed to your sound system at the first place where it connects to the
components.
●
Disconnect the cable TV wire where it is connected at the wall outlet.
●
Turn your system back on and listen if the hum has disappeared. If removing the cable TV feed
has eliminated the hum, you will need to insert a Ground Loop Isolator before reconnecting the
cable TV feed. If that does not help then contact your cable TV provider so they can better isolate
your cable feed.
Suggestion #2:
Turn off all components in your system.
●
Disconnect the input cables at the amplifier.
●
Turn the amplifier back on and see if the hum is still present.
●
If the hum disappears the fault may be in the input cables being used. Try replacing them with
cables that have better shielding and make certain that the input cables are not running on top of
any AC power cords.
●
Try disconnecting each cable one at a time to determine if one or all cables affect the noise.
●
If the hum disappears when the input cables are disconnected but returns after the cables are
changed and the sound system re-connected, then the problem may be caused by one of your
source devices. To check this, disconnect each device one at a time to determine which is causing
the problem.
Suggestion #3:
Ground loop problems may also be caused by poor grounding of the electrical system in your
home, particularly when there are multiple components with three-prong, grounded power cords.
●
Try unplugging these components one at a time and see if one or all of them is causing the
problem.
