Simaudio i 3.3 - Manual (Page 11)

MOON i 3.3 Integrated Amplifier
Optional Balanced Input
The balanced input option provides for one additional line-level input on an XLR connector. The “B1” input uses a fully
balanced differential circuit and is intended for use with a source component that outputs a fully balanced differential signal.
The MOON i
3.3 optional balanced input takes full advantage of the benefits of balanced circuitry:
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 i
3.3, 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.
Rear Panel Connections
Figure 4: MOON i 3.3 Rear panel
The rear panel will look similar to Figure 4 (above). There are four (4) pairs of single-ended analog inputs on RCA connectors
labeled CD, A1, A2 and A3/P. The left channel inputs are located on top and the corresponding right channel inputs are
located directly below. In the event that your MOON i
3.3 is equipped with the aforementioned optional phono section, the
input labeled ‘A3/P’ must be used to connect your turntable interconnect leads to this integrated amplifier. If you don’t have
the optional phono section installed, then this input can be used in the same way as CD, A1 and A2 inputs.
The MOON i 3.3 integrated amplifier also has two pairs of non-amplified outputs labeled ‘FIX’ and ‘VAR’, located next to the
A3/P input. The ‘FIX’ output is intended as an input to a recording device such as a cassette tape deck or CD-Recorder Player.
Keep in mind that the output level is fixed and cannot be adjusted by the i
3.3’s volume control. The ‘VAR’ output is
designated for output to a power amplifier with single-ended RCA inputs in the event that you wish to use your MOON i 3.3
as a preamplifier only. Keep in mind that the output level is variable and adjusted by the i 3.3’s volume control.
In the event that your MOON i 3.3 is equipped with the aforementioned the balanced input option, you will find one pair of
XLR balanced inputs to the right of these non-amplified outputs. These are intended to be used with a source component that
outputs a balanced signal.
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Optional Balanced Input / Rear Panel Connections 11