Emotiva RPA-1 - Manual (Page 23)

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Turn-on and turn-off thumps
• Plug the amplifier into an un-switched AC outlet, and use the 2 wire Trigger Input connection with a trigger
between 5-12VDC from the source unit or preamplifier (such as the Emotiva RSP-1 Preamplifier). This should
allow the amplifier to turn on and off silently.
• If your powered subwoofer is the cause of the “thump” sound (not the other speakers connected to RPA-1), plug it
into a different 110VAC outlet than the RPA-1 amplifier so there is no power surge conflict.
• Install a line conditioning device. Contact Emotiva or a professional installation specialist for details.
“Hum” Noises in the Speakers
This problem is more than likely caused by a “ground loop” in your system, rather than a fault in the RPA-1.
Follow these steps to isolate the main cause of the hum, there may even be more than one. Remember
to turn off all components in your system, including the RPA-1, before disconnecting or connecting any
cables.
• Remember to turn off all components in your system, including the amplifier, before disconnecting or connecting
any cables during troubleshooting.
• Try to have all of your equipment on the same electrical outlet or circuit. Group all the low power components
(preamp, CD player, DVD etc.) on a single outlet or power strip. This is provided that the overall current draw
from your equipment does not exceed the rating of the outlet or breaker.
• Disconnect all cables which come from outside the room, and check if the hum goes away. This includes such
connections as cable TV, satellite TV, or roof top antennas. Make sure that they are disconnected where they
first enter the room, so they are making no connection to the preamplifier or the TV, or any other component. If
the hum is caused by the cable TV line, then you will need a “ground loop isolator.” This is an inexpensive device
fitted in line with the coaxial cable feed. Contact your cable company or your Emotiva Dealer for assistance.
• Disconnect all connections from the preamplifier to your TV, VCR or DVD.
• As a test, disconnect any other component which has a grounded power cord.
NOTE: Never remove the ground pin from any power cords (if present). This is very dangerous.
• If the hum persists, disconnect all the source components one at a time from the back of the preamplifier, until
you identify the problem.
• Try moving the speaker cables away from any power cords. Try just one speaker, connecting it to each amplifier
channel and see if one channel is bad.
• Check that the interconnect cables to the amplifier do not have any broken connections. The best way to do this
is to substitute a known good connection for the suspect connection. If you reverse the cables and the problem
goes away, the cable may be damaged or broken. This is possible even if you can’t physically see the break as the
strain for pulling on audio cables can sometimes break the wire internally.
Ground loop isolators are available for audio lines and video devices. If you need assistance, contact your
Emotiva Dealer. Although this is not always an ideal solution, the grounding differences between certain
home entertainment components sometimes require ground loop isolators. This is the exception rather than
the rule.