www.lectrosonics.com
11
Input gain
control
Some transmitters from brands other than Lectrosonics can also be used
if the appropriate compatibility mode set is set in the receiver. Observe the
audio level meter on the LR receiver LCD as you adjust the input gain on the
transmitter to see the modulation level. Some models may have limiters on the
input to suppress overload distortion, and others may not. Monitor the audio,
preferably with headphones, as you adjust the input gain to find the maximum
level that can be set without audible limiting or overload distortion.
6) Set Receiver Audio Output Level
The audio output can be adjusted from -50 dBu (mic level) to +5 dBu (line
level) in 1 dB steps. The signal to noise ratio of the audio output does not
change across the range of adjustment. Therefore, it is best to use an output
level high enough to drive the connected device to full level without the need
for additional gain. If the receiver is set to full output and the level is still not
sufficient to drive the connected device to full level, then some gain will need
to be applied by the connected device.
A built-in tone generator makes matching the output level to the connected
device easy and accurate.
1) Navigate to
Audio Level in the LR receiver menu and press MENU/
SEL to enter the setup screen. Use the arrow keys to reduce the level to
minimum (-50 dBu).
2) Turn on the 1k tone (MENU/SEL + UP arrow) in the
Audio Level setup
screen.
3) On the connected device, set the input to “line level” if available. Turn the
input gain control (e.g. record level) all the way down.
4) Gradually increase the output level on the receiver while observing the
input level meter on the connected device. Increase the level until a full
scale reading is indicated on the input level meter.
5) If a full scale reading cannot be achieved, increase the input gain control
on the connected device gradually until a full scale reading is achieved.
Once this level match has been set, leave these settings alone and make
adjustments from one event to another with the input gain control on the
transmitter.
NOTE: If your camera or recorder does not provide limiting on the
input, set the level as described above a few dB below a full scale
reading (3 or 4 dB is usually enough).
The UM400A transmitter shown here is typical of
many legacy Lectrosonics models.
LECTROSONICS
UM400a
OFF ON
AUDIO
LEVEL
–10
–20
ANTENNA
Modulation
level LEDs
