The A Input is via a standard female XLR-3 connector and it is set for
MICROPHONE sources. The input is electronically balanced and it is factory-
preset for around – 60 dB level.
The recessed GAIN A trimmer allows you to adjust in a very precise way the gain
of the „A‟ source. In conjunction with the GAIN potentiometer (see) this allows you
to adjust the overall gain to any desired figure within the available range.
The A PHANTOM jumper on the PCB (see par. 0) applies phantom powering
+48V to the MIC input A socket for condenser microphones.
WARNING: The Phantom power is used to power microphones with built-in
condenser or electrect preamplifiers. This system requires both conductors to
have the same D.C.potential. So, it’s indispensable that cables and connectors are
balanced and in perfect condition. If these rules are observed, Phantom power can
be applied even dynamic microphones are connected, although it’s preferable to
avoid doing so.
The B Input is via a standard female 1/4” Jack connector and it is set for signals
providing a signal LINE level such as tape machines, RadioMic receivers, ISDN
codecs. The input is electronically balanced and factory-preset for a 0 dB level.
Only one of the two inputs (Input A or Input B) will be active at any time,
depending upon the setting of the A/B switch (see)
An unbalanced INSERT socket (A) is provided which is a break point in the input
channel signal path. The insert point allows external piece of equipment such as
limiters, compressors and other signal processing units to be added as required to
particular input channels.
The Insert is a 3-pole 1/4” Jack Socket, which is normally by-passed. When a jack
plug is inserted, the signal path is broken at a point just after the preamplifier
stage, but before the Input Selection (A/B SEL key). The signal from the channel
appears on the TIP of the plug and is returned on the RING to continue through to
the final output.