Operating Instructions - Lectrosonics AM8 Instruction Manual

AM8

Operating Instructions

Setup of the AM8 consists of choosing rear panel dip
switch options, setting front panel levels, and adjusting
the compressor/leveller (if used). Using the Remote
Level Control capability of the AM8 is addressed in the
next section. When the power is turned on to the AM8,
it will display its LecNet address on the Channel On
LEDs for 1.5 seconds before entering normal operation.
Channel 8 On LED represents the most significant bit of
the binary address, while Channel 1 On LED represents
the least significant bit.
1) Select Auto or Direct mode using dip switch 1 on
channels 1-8. Normally, all speech microphones
would be in the Auto mode. Microphones used for
music (e.g. choir mics in a church sound system),
or inputs attached to line level devices like tape
players or VCRs are best used in the Direct mode.
The Remote Level Control terminals may be used
to manually turn off Direct mode microphones when
they are not in use.
2) Turn Phantom power on or off as needed, using dip
switch 2 on channels 1-8. Dynamic microphones
need no phantom power, but electret types will
need phantom power to operate properly.
3) Set up the preamplifier gain using dip switches 3
and 4 on channels 1-8. The 0dB position is used
for line level sources like tape players or VCRs. The
30dB position works well for higher output micro-
phones like electrets. The 50dB position is best for
dynamic microphones, or electret types where the
distance from the talker to the microphone is more
than 3 feet or so.
4) Set the Main Level control between 5 and 6. While
speaking into each microphone in turn, adjust the
Channel Level to give adequate volume level. The
normal operating position of the Channel Level
control should be between 10 o'clock and 2 o'clock.
Try to adjust all microphones to about the same
volume level, as this will result in the most optimum
automatic action.
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5) If the compressor/leveller system is to be used,
switch the In/Out front panel switch to the In posi-
tion. With a normal talker, adjust the Threshold pot
until the 3dB Gain Reduction LED flickers on. The
system volume level may need to be readjusted at
this point using the Main Level control. Next, check
that a loud talker turns on most or all of the remain-
ing Gain Reduction LEDs. Finally, with a soft talker
such that no Gain Reduction LEDs are lit, be sure
there is no feedback or ringing in the system.
The system is now ready for use.
Note: Be sure to set the AM8 back to "Local"
mode after using the software-based control panel
on a PC. If the unit was left in "Remote" mode and
there is no PC available, it will be necessary to
perform a "Reset to Local" procedure.
1. Turn off the power to the AM8.
2. Short Pin 10 to pin 15 on the rear panel DB15
connector while turning on the power switch.
3. Remove the short from pins 10 and 15.
All subsystems are now in "Local" mode and control-
lable from the AM8 front/rear panel.
There are three subsystems that can be effectively
disabled if they are left in "Remote" mode:
1. The Compressor/Leveller subsystem. If this func-
tion is in "Remote", the symptoms will be no re-
sponse from the Threshold control and the In/Out
switch.
2. The Auto/Direct function. If this function is in
"Remote," the AM8 will ignore the state of the rear
panel
dipswitches.
3. The Remote Level Control subsystem. If this func-
tion is in "Remote", there will be no response from
the remote level control.
LECTROSONICS, INC.