Shure AMS8100 User Giude page 17

SUGGESTED LOGIC APPLICATIONS
This section contains suggestions on the uses of the
AMS8100's logic capabilities. Note that uses of these func-
tions are not limited to the listed applications. The user is limit-
ed only by individual imagination and creativity. For additional
suggestions and solutions to installation problems, contact
Shure's Applications Group at 847--866--2525.
In the following paragraphs, the wiring diagrams refer to
the DB-25 connector pins shown in Figure 10.
Cough Button
The talker can turn off his or her microphone during
coughing or private conversations by installing an SPST push-
button switch between the MUTE IN and Logic Ground pins for
each channel to be modified (see illustration COUGH BUT-
TONS—Channels 1, 2 and 3 modified). When a channel is
muted, no audio is passed. (See "Dead Zone on MUTE IN De-
feat" in Internal Modifications section for more information on
MUTE IN logic.)
M1 M3
M2
COUGH BUTTONS
Chairperson-Controlled Muting
The chairperson can, by activating a switch, silence all
other microphones and be heard without interruption. For op-
eration in this mode, connect all the MUTE IN pins together ex-
cept that of the chairperson's channel, and wire an SPST
pushbutton or toggle switch between those MUTE IN pins and
Logic Ground pin (see illustration CHAIRPERSON—CON-
TROLLED MUTING—the chairperson is shown as Channel
1).
An alternative to a switch is to connect the chairperson's
GATE OUT to the MUTE IN of other channels. When the chair-
person's microphone activates, all other microphones mute.
NOTE: If the chairperson's microphone activates for any rea-
son (cough, sneeze, etc.) all other microphones will be muted.
CH. 1
M3
M2 M4
CHAIRPERSON--CONTROLLED MUTING
LOGIC
GROUND
LOGIC
GROUND
M5 M5 M7
M6
English --
Remote Channel-On Indicators
Remote indicators can be used to indicate when a talker's
microphone is on. Connect the LEDs and a 5-volt supply to the
GATE OUT pins as shown in the illustration REMOTE CHAN-
NEL-ON INDICATORS (Channels 1, 2 and 3 shown modified).
To avoid switching clicks in the audio output, do not ground the
power supply negative terminal in the audio system or rack
ground. IMPORTANT: If a single cable is used for the micro-
phone audio signal and the LED dc power, separate shielded
pairs must be used. Failure to carry the dc power on a shielded
pair may result in audible clicking due to capacitive coupling
between the dc power lines and microphone lines.
+
R
R
G1 G3
G2
REMOTE CHANNEL--ON INDICATORS
Disabling the Gating Function (Bypass)
To keep certain microphones on at all times, wire the de-
sired microphone channel's OVERRIDE IN pins together to
the Logic Ground pin. The selected channels now function as
they would in a non-automatic mixer (see illustration GATING
BYPASS—Channels 1, 2 and 3 modified).
O2
O1 O3
GATING BYPASS
Inhibiting Gating for Unwanted Sounds
As described in the Operating Principles section, MaxBus
attempts to activate only one microphone per sound source.
Muting a microphone channel prevents its audio from appear-
ing at the mixer's output. However, the muted microphone still
communicates with other mic channels via MaxBus. A sound
source picked up by a muted microphone will not activate other
microphones.
Sound sources that may cause unwanted microphone
channel activation include:
·
A noisy fax machine or printer
·
A squeaky door
·
A paging system loudspeaker
·
An audio teleconferencing return signal loudspeaker
18
--
5 V POWER
SUPPLY
LOGIC
GROUND
R = 470 W , 1/4 W
LOGIC
GROUND