MOON P-7 Dual-Mono Preamplifier
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 both the
preamplifier and amplifier, then 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 +10 Volts, the other will be carrying a
signal of –10 Volts. When these two inverted signals on a balanced line are output from the MOON P-7, 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 not be processed.
Remote Control Operation
The MOON P-7 Dual-Mono preamplifier uses the ‘FRM-2’ full function, all aluminum
remote control (figure 4). It operates on the Philips RC-5 communication protocol and
can be used with other MOON components.
The ‘FRM-2’ remote uses three AAA batteries (included). To install them, use the
supplied Allen key to remove the three screws located on the back plate; insert the
batteries in the correct direction and then screw the back plate back into place.
To operate the P-7 with this remote control, you must first press the button labeled
‘Preamp’ in the top right corner.
The POWER button switches the P-7 between ‘Standby’ and ‘On’ mode.
The INPUT button temporarily assigns the and buttons to perform the same
function as the “+” and “-” input buttons located on the controller’s front panel; allowing
you to sequentially scroll through each of the preamplifier’s inputs. After five seconds of
inactivity, the and buttons will again control channel balance (see below).
The VOL+ and VOL– buttons increase and decrease the volume level. From 30 to 80dB,
holding either button down results in 1.0dB volume changes; repeatedly pressing either
button very briefly results in 0.1dB volume changes.
The and buttons control channel balance; Pressing the left arrow button causes a
decrease in the volume level of the right channel; pressing the right arrow button causes
a decrease in the volume level of the left channel. The balance adjustment operates in
1% increments. When the balance is equal for both channels, “ 00 ” will appear in the
front panel display. The range for the balance control varies from “ 100” for left
channel only to “100 ” for right channel only.
The MUTE button, located in the middle of the volume and balance buttons, performs the
identical function as the ‘Mute’ button located on the P-7’s front panel.
Figure 3: FRM-2 Remote Control
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Balanced Operation / Remote Control Operation 13