Hafler 9130 - Manual (Page 13)

CLEANING/
MAINTENANCE
SPECIAL NOTE ON VIDEO CABLE “GROUNDS”: As mentioned above, the ground conductor of
cable service and antenna feeds should be connected to earth ground. Often, however, due to long
feed lengths, especially in apartment distribution systems, this ground will be of poor quality and could
be a source of noise. This interference is usually characterized by a high frequency noise, rather than
a hum or a buzz. If such interference is experienced, a separate earth ground connection should be
made from the cable outlet nearest the audio/video equipment to a known good earth ground.
If ground loops exist due to potential differences in the interconnects in rack mounted systems, then
it is advisable to isolate the preamplifier chassis from the rack rails. This may be accomplished by
sandwiching a thin sheet of insulating material (i.e., plastic washers or several layers of electrical tape,
etc.) between the rack and the preamplifier, and securing the unit with non-metallic (i.e., nylon, etc.)
hardware. It may be necessary to insulate other components so that only one component is directly
connected to the rack rails.
If the faceplate should become soiled, it may be cleaned with a slightly damp, soft cloth and, if
necessary, a mild detergent. Do not use any abrasive cleaners or solvents. Unplug the power cord
before attempting any cleaning operations.
Except as specifically detailed in the owners manual, there are no user serviceable parts or
adjustments inside the 9130 Amplifier, and all servicing should be referred to qualified, authorized
personnel.
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