C372说明书对于外接前级（包括解码前级）是这么说的：
9. MAIN IN
Connections to an external pre-amplifier or processor, such as a
surround-sound decoder. In normal use these are connected to the Pre-
Out 1 sockets (No. 8) with the links supplied. To connect your NAD
C 372 to external processor or pre-amplifier first remove these links. Use
a twin RCA-to-RCA lead to connect to the left and right 'Audio Output'
of the pre-amp or processor to the Main-In sockets.
NOTES: Always turn the C 372 and associated external power
amplifiers off before connecting or disconnecting anything to the PREOUT
1, 2 and MAIN-IN sockets.
The PRE-OUT 1&2 output signals will be affected by the NAD C 372's
volume and tone control settings.
.
