Classe Audio CA-M400 Owner's Manual page 17

Technically, balanced audio interconnections provide two distinct
benefits: they double the signal's strength as it travels from one
component to the next, increasing the potential signal to noise ra-
tio by 6 dB; they also do an excellent job of rejecting noise and
interference that might otherwise be picked up between the com-
ponents, due to either EMI (electromagnetic interference) or RFI
(radio frequency interference). In our modern world of wireless
telecommunications, there is more potential interference floating
around us than ever before—it makes sense to keep it all out of our
music and movie soundtracks.
For this reason, we strongly recommend using the balanced analog
interconnections between your Classé components wherever
possible.
The pin assignments of these XLR-type female input connectors
are:
Pin 1: Signal ground
PUSH
Pin 2: Signal + (non-inverting)
2 1
3
Pin 3: Signal – (inverting)
Connector ground lug: chassis ground
These pin assignments are consistent with the standards adopted by
the Audio Engineering Society.
If you are using your Classé amplifier with a Classé preamplifier,
you're all set. Just buy a standard balanced interconnect and plug it
in. Then engage that input on the power amplifier by configuring
it as described in Initial Setup.
If you are using another brand of preamplifier, please refer to the
operating manual of your balanced-output preamplifier to verify
that the pin assignments of its output connectors correspond to
your amplifier. If not, have your dealer wire the cables so that the
appropriate output pin connects to the equivalent input pin.
2 Single-Ended (RCA) Input
Single-ended cables using RCA connectors are the most common
form of analog connection used in consumer electronics. When
implemented carefully and with use of high quality interconnect-
ing cables, this standard can provide excellent performance. Classé
has gone to extraordinary effort to ensure that the single-ended
(RCA) inputs of your power amplifier are as good as possible.
However, this connection standard cannot offer the immunity from
interference that balanced interconnection does—hence our
recommendation to use the balanced inputs when possible.
If you elect to use the single-ended input of your Classé power
amplifier, you need to engage it by configuring the amplifier as de-
scribed in Initial Setup.
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