Emotiva MPS-1 - Manual (Page 32)

Page 32 Page 33
speakers play the full range. Make sure that the preamplifier has been correctly set. If you are not using
a subwoofer, set the speaker options to “Large” where possible.
• Check that the speaker wires have been connected correctly: Make sure that the positive of each speaker
connects to a positive output of the amplifier, and the negative of each speaker connects to a nega-
tive output. If one speaker is wired incorrectly, than it will be “out of phase” with the others, resulting
in poor bass performance.
• If you have connected the amplifier using the XLR inputs, make sure that the XLR cables are wired cor-
rectly. If one has the hot and cold reversed (pins #2 and #3), then this will also cause a speaker to be
out of phase.
Turn-on and turn-off thumps
• Plug the amplifier into an un-switched AC outlet, and use the SIGNAL position of the turn on switch at
the back of the amplifier. This will allow the amplifier to turn on and off silently.
“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
MPS-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 MPS-1, before disconnecting
or connecting any cables.
• If your preamplifier has XLR balanced outputs, use them because they offer greater immunity to noise
fields.
• 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 com-
ponents (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 (unless purchased through AV123) 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 preampli-
fier, 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.