Manual

860A Dual-Mono Power Amplifier
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9
Connecting the 860A
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
inputs, respectively. We highly recommend that
you use the balanced XLR inputs (provided that
your preamplifier has balanced outputs) to take
full advantage of 860A Stereo 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 860A and the connected
equipment can result that is not covered
by warranty.
Don’t hesitate to use high quality interconnect
cables*. Poor quality interconnect cables can
degrade the overall sonic performance of your
system. It is recommended, though not
mandatory, to use balanced interconnects
between your preamplifier and the 860A when
using long cable runs (i.e. more than 3 meters
in length).
2. Connect your speakers, with the cables of your
choice, to the 860A’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.
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
860A 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 860A, 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.