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-20dB attenuator. Adjust the recorder input control for the optimum
recording level.
2. INSTALLATION
A. AUDIO TERMINATIONS
1. Input connections are made via female XLR connectors with pin 2
positive, pin 3 negative and pin 1 ground. 48V phantom power is
supplied on pins 2 and 3.
2. Output connections are made via male XLR connectors with pin 2
positive, pin 3 negative and pin 1 ground. If the output is to be used
unbalanced, pin 1 should be connected to signal ground and pin 2 to
signal hot. Due to the nature of the balanced output stage, pin 3
should be left open for unbalanced operation. See figure below.
Note: This will provide a signal of positive absolute polarity when the
preamplifier is being used with a microphone which produces a
positive voltage on pin 2 with positive air pressure on the front of the
diaphragm. While a vast majority of microphones conform to this
standard a few do not. Use the phase reverse switch to compensate if
necessary.
Figure 2. Unbalanced output cable termination
3. The balanced output driver is capable of driving a matched 600
Ω
line.
This type of termination can be very advantageous for driving very
long lines because it provides maximum power transfer through the
cable. With a higher power music signal, aberrations caused by
distributed capacitance and inductance in the cable are minimized
which improves transient performance and harmonic integrity. To
create a 600
Ω
balanced line, simply connect a 301
Ω
1% metal film
resistor between pins 2 and 3 at the destination end of the cable. This
termination combines with the preamplifiers 300
Ω
output impedance
to provide a matched 600
Ω
line.
1
2
3
SHIELD
HOT
XLR FEMALE
