User's Manual

Digital Plug-On Transmitter
Rio Rancho, NM
13
Selecting the Low Frequency Roll-off
It is possible that the low frequency roll-off point could
affect the gain setting, so it’s generally good practice to
make this adjustment before adjusting the input gain.
The point at which the roll-off takes place can be set
to:
• 25 Hz • 100 Hz
• 35 Hz • 120 Hz
• 50 Hz • 150 Hz
• 70 Hz
The roll-off is often adjusted by ear while monitoring
the audio.
.
Input...
Gain
Rolloff
Phase
Rolloff
70 Hz
Selecting Audio Polarity (Phase)
Audio polarity can be inverted at the transmitter so the
audio can be mixed with other microphones without
comb filtering. The polarity can also be inverted at the
receiver outputs.
Input...
Gain
Rolloff
Phase
Phase
Normal
Invert
Selecting Phantom Power Supply
Input...
Rolloff
Phase
Phantom
Phantom
15V
The transmitter input jack can provide phantom power
for the attached microphone if needed, with voltages
at 5, 15 or 48. Phantom power will consume a slight
amount of battery power, so it can also be turned off.
About the Phantom Power Supply
Three phantom voltages are selectable from the con-
trol panel. The voltages are:
• 5 Volts for lavaliere microphones,
• 15 Volts for some professional mics requiring high
current and for many common stage mics that will
operate over a wide phantom Voltage range of 12
to 48 Volts. With the proper adapter, this position
can also be used with T power microphones. See
our web site for details on finding or making the
proper adapter.
• 48 Volts for microphones that do in fact require
a supply greater than 18 Volts. (See below for a
discussion of why 42 and not a “true” 48 Volts.)
For longest battery life use the minimum phantom
voltage necessary for the microphone. Many stage
microphones regulate the 48 Volts down to 10 Volts
internally anyway, so you might as well use the 15 Volt
setting and save some battery power. If you are not
using a microphone for the input device, or are using a
microphone that does not require phantom power, turn
the phantom power off.
Phantom power should only be used with a fully float-
ing, balanced device, such as common microphones
with a 3-pin XLR connector. If you use the phantom
power with an unbalanced device or if pins 2 or 3 are
DC connected to ground, then you will draw maxi-
mum current from the power supply. The DPR is fully
protected against such shorts but the batteries will be
drained at twice the normal rate.
The transmitter can supply 4 mA at 42 Volts, 8 mA at
15 Volts, and 8 mA at 5 Volts. The 42 Volts setting actu-
ally supplies the same voltage to a 48 Volt microphone
as the DIN standard arrangement due to a dynamic
biasing scheme that does not have as much voltage
drop as the DIN standard. The 48 Volt DIN standard
arrangement protects against shorts and high fault
current with high resistance in the power supply feeds
to pins 2 and 3. This provides protection if the sup-
ply current is accidentally shorted to ground and also
keeps the microphone from being attenuated by the
power supply.
The DPR improves on those functions and is able to
use less power from the battery by using constant
current sources and current limiters. With this dynamic
arrangement, the DPR can also supply more than
twice the current of competing 48 Volt plug on units
and provide four times the current for some very high
end 15 Volt microphones.