Owners Manual
A Few Words About Hum and Noise
Potential Ground Loops in a Complex A/V Systemtical and expensive. In some cases, the use of an approved AC Power Isolation
Transformer of sufcient capacity may solve this problem.
Suggestion #1
To determine if a cable TV connection is responsible for the hum, rst turn all Warning: if you suspect that the grounding system in your home?s electrical
components off. Disconnect the cable TV feed to your system at the rst place wiring is causing the hum problem, it is important that you do not make any
where it connects to your components. Alternatively, disconnect the cable TV changes to the wiring yourself. Only a licensed electrician should make any
wire where it is connected at the wall outlet. Turn your system back on, and changes to household wiring, and they must be made in full compliance with
listen if the hum has disappeared. If removing the cable TV feed has eliminated all local building, safety and electrical codes.
the hum, you will need to insert a Ground Loop Isolator before reconnecting Suggestion #4
the cable TV feed, or contact your cable TV operator to see if they can better Hum may also be caused by faulty earth grounds in your home?s electrical
isolate your cable feed.system. In the past, cold water pipes were often used for the earth ground, so
Suggestion #2it is important to make sure that your ground connection is still valid and has
Turn off all components in your system, and then disconnect the input cables not become loose or corroded. The cold water pipe method may no longer be
at the amplier. Turn the amplier back on, and see if the hum is still present. valid in some locations due to requirements that the water meter be isolated
If the hum disappears, the fault may be in the input cables used. Try replacing from the water mains with a length of PVC pipe, thus interrupting the ground
them with cables that have better shielding, and make certain that the input circuit. The safest, and most reliable, approach may be to provide your own
cables are not running on top of any AC power cords. Change the cables one ground. This can be accomplished by having a licensed electrician drive at
at a time to determine if one, or all cables is responsive. If the hum disappears least ve feet of copper-jacketed steel grounding rod into the earth, and using
when the input cables are disconnected, but returns after the cables are changed
that for your grounding connection.
and the system re-connected, the problem may be caused by your processor,
receiver or preamplier.Suggestion #5
If you have hum in your video display device (bars that roll up through image
Suggestion #3
Ground loop problems may also be caused by poor grounding of the electrical at 12-14 second intervals), this may be related to hum you also experience in
your audio system. The previous suggestion tips may help with this also. If not,
system in your home, particularly when there are multiple components with
three prong, grounded, power cords. Try unplugging these components one try isolating the ground in the projectors video signal cable with a base-band
video isolation transformer, such as the Jensen VB-1BB.
at a time, and see if one or all of them is causing the problem. The ultimate
solution to this type of problem is to re-wire your house with an isolated, star If the hum persists after all of the above suggestions have been tried, contact
type grounding conguration. We recognize, however, that this may be imprac-the Outlaw Audio customer service department for assistance.
Ground Loop Diagram
Set-top Box
Coax Cable
Cable Feed
A/V
Cables
60Hz AC60Hz AC
Ground LoopGround Loop
AC LineAC Line
AC Ground
Main House
Grounding
Seven-Channel P9ower Amplier |
ACEC
