Troubleshooting | or the first component the cable is connected to (i.e. the | |
cable box, or VCR). If the hum is no longer present, you | ||
Use the troubleshooting notes above to solve common | must insert a “75Ω ground loop isolator” before reconnect- | |
situations that don’t require professional attention. If the | ing the line. You should check with your ADCOM dealer to | |
steps stated in possible solution do not resolve your prob- | obtain one. If the “75Ω ground loop isolator” works only | |
lem, then please contact your ADCOM dealer or call the | partially or not at all, then please read note 2 to complete | |
ADCOM customer service department. Any problems not | the troubleshooting procedure. | |
covered here should be brought to the attention of your | Note 2: Make sure that the power amplifier is at least 6” | |
ADCOM dealer or ADCOM customer service department. | from processor or other equipment using microprocessors. | |
A special note on “hum:” When there is a | Usually putting another component between them is suf- | |
“hum” audible throughout your speakers, even with the | ficient to minimize the hum. If this does not reduce the | |
main volume turned all the way down, you have a com- | hum, turn the system off and disconnect all Inputs from | |
mon phenomenon known as a “ground loop.” A ground loop | the amplifier. If the hum still persists, then your dealer or | |
is basically a difference in ground voltages between two | service center must examine the unit/system. If the hum | |
or more components which are connected electrically and | disappears, try another set of RCA cables. Connect one RCA | |
which creates multiple current paths where there must only | cable at a time to see if one specific cable is responsible. | |
be one. This difference in potentials creates a 60Hz low- | If any or all cables cause the hum to appear, then the unit | |
level sound (approximately a low A), that seems to “hum.” | should be evaluated for proper operation by your dealer or | |
It can be caused by adding new components to your system, | authorized service center. Please see our website or call us | |
for a list of authorized service centers in your area. | ||
but that does not imply there is anything electrically wrong | ||
| ||
with any new component. With the advent of audio/video | Servicing | |
and home theater systems, the problem has become com- | ||
monplace. Generally, the cause is the | ADCOM has a technical service department to answer | |
signal line. This new incoming line may add an additional | questions pertinent to the installation and operation of your | |
ground at a different potential to the AC line ground of | unit. In the event of difficulty, please contact us for prompt | |
your other equipment (refer to note I and 2, to trouble- | advice. If your problem cannot be resolved through our | |
shoot a hum problem). | combined efforts, we may refer you to an authorized repair | |
Note 1: Cable TV systems can sometimes contribute to | agency, or authorize return of the unit to our factory. To aid | |
ground loop problems which cause “hum.” To determine | us in directing you to a convenient service center, it would | |
if your cable system is the contributing factor, disconnect | be helpful if you indicate which major city is accessible to | |
the | your home. |
may exhibit occasional anomalies arising from AC line surges, etc. If you experience unexpected behavior, or if the
This unit is manufactured under license from Dolby Laboratories Licensing Corporation. It is additionally licensed under one or more of the following patents: U.S. number 3,959,950, Canadian numbers 1,004,603 and 1,037,877. Dolby® Pro Logic®, and Dolby Digital® are registered trademarks of Dolby Laboratories Licensing Corporation.
Manufactured under license from Digital Theater Systems, Inc. US Patent Number 5,451,942 and other world- wide patents issued and pending. “DTS,” “dts,” “DTS Digital Surround,” are trademarks of Digital Theater Systems, Inc. Copyright 1996 Digital Theater Systems, Inc. All Rights Reserve
