Connecting the 880m, Balanced operation – Simaudio 880M Amplifier User Manual
Page 9
 
 
880M Reference Mono Power Amplifier
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9
Connecting the 880M
 
Prior to making any connections or removing the 
XLR jumpers, the power amplifier must be turned off 
and the AC cable disconnected for at least 1 minute.
 
1. Connect the input cables running from your 
preamplifier’s outputs, whether balanced or
single-ended, to the amplifier’ s XLR or RCA 
input, respectively. We highly recommend that 
you use the balanced XLR input (provided that
your preamplifier has balanced outputs) to take
full advantage of 880M Power Amplifier’s
capabilities. Please refer to the next section, 
“Balanced Operation” on for further information. 
 
Do not connect cables to both the XLR and 
RCA inputs at the same time. Damage to
both the MOON 880M and the connected
equipment can result that is not covered 
by warranty. 
 
Don’t hesitate to use a high quality interconnect
cable*. A poor quality interconnect cable can
degrade the overall sonic performance of your
system. It is recommended, though not 
mandatory, to use balanced interconnects 
between your preamplifier and the MOON
880M when using long cable runs (i.e. more
than 3 meters in length).
2. Connect your speaker, with the cable of your
choice, to the MOON 880M’s speaker binding
posts. Take care to respect the polarity (“+” , “-
” ) of the outputs. Once again, don’t hesitate to 
use high quality speaker cables*. Poor quality
speaker cables can degrade the overall sonic
performance of your system. Both pairs of
speaker connectors are internally connected 
together. Consequently, it doesn’t matter which 
pair you use.
 
3. Connect the supplied AC power cable to the IEC 
receptacle, located on the amplifier’s rear panel.
Ensure that the AC wall outlet you use has a 
functioning ground. For the best sonic 
performance, it is preferable that you plug your
MOON 880M directly into a dedicated AC outlet
and avoid using an extension cord. If you have
the time and willingness, consider installing a
superior quality AC wall outlet such as a hospital 
grade Hubbell*. 
* Please speak with your MOON Authorized Retailer 
about the benefits of high quality cables for your 
system, and superior quality AC wall outlet.
 
 
Balanced Operation
When using an unbalanced interconnect, the audio 
signal runs through both the center wire and the 
shield/ground wire. Any noise picked up by this
interconnect (ie. nearby magnetic fields such as an
AC power cord) will be reproduced by the amplifier
and heard through the loudspeakers. Conversely, a
balanced interconnect has three separate 
conductors; one for the ground and two for the 
actual signal. These two signals are identical except
that one is 180 degrees out of phase with the other.
For example, when one conductor is carrying a 
signal of +5 Volts, the other will be carrying a signal 
of –5 Volts. When these two inverted signals on a
balanced line are input into a differential power
amplifier such as the MOON 880M, any noise
picked up by the interconnect will be eliminated
since a differential circuit amplifies only the 
difference between these two signals: Noise on a 
balanced interconnect will be equal on both
conductors and therefore cancel out.