Shure SCM810 User Manual page 15

SCM810 Speech Gate for Mixing Console
The SCM810 can be used in conjunction with large mixing
consoles to provide automatic mixing for talk shows, panel dis-
cussions, and news shows. Large consoles have channel insert
jacks so that external signal processing devices can be patched
into individual channel signal paths. With this modification the
SCM810 can be placed into unbalanced insert jacks, and the
SCM810 used as a high-quality, external, 8-channel speech
gate. This arrangement allows the operator complete control of
each channel via the console's input control strip, while the
SCM810 keeps the number of open microphones to a minimum.
In this operational mode:
1. The Direct Out jack tip is the input from the mixing console, and
the ring is the output to the mixing console.
2. The SCM810 channel inputs, faders and EQ do not function.
3. NOMA does not function, channel Off-Attenuation is infinite.
4. The front-panel channel overload indicators indicate gating
and overload for each input.
5. The "Local" operating mode provides a non-automatic audio
signal at the output for use in external mixes.
6. If the insert point on the mixing console is pre-fader, the gain trims
should be set such that all microphone levels are similar.
MUTE IN Precedence to OVERRIDE IN Precedence
With this modification and when both MUTE IN and OVERRIDE
IN logic are grounded for a channel, the Override mode will take
precedence (as supplied, the MUTE IN takes precedence over
OVERRIDE IN).
Dead Zone on MUTE IN Defeat
As supplied, MUTE IN is intended for use as a momentary cough
button or privacy function (mute when necessary). However, if
the MUTE IN is intended to be used so that the talker must un-
mute microphones to enable speech pickup (unmute when
needed), this modification is needed. This removes the muted
channel from the MaxBus which eliminates "dead zones." A dead
zone is an area in which a microphone picks up a talker through a
muted microphone and other microphones do not activate for
that talker.
Change MUTE IN to Inhibit
As supplied, a channel will mute when its MUTE IN terminal is
grounded. The mute function can be changed to "Inhibit" by an in-
ternal modification for each channel. After the modification, a logic
"Low" at the MUTE IN terminal prevents that channel from gating
on if it is off, but allows it to remain on if it is already on.
IMPORTANT: To prevent high-frequency oscillation, never con-
nect a channel's GATE OUT to its own MUTE IN unless the "In-
hibit" modification has been made.
Change OVERRIDE IN to MUTE IN for Use with Filibuster Mode
This modification should only be performed with the Change
MUTE IN to Inhibit modification described above.
Change Off-Attenuation Level
This modification changes the off-attenuation level from -15 dB
to a selected value. Select from the following resistor values.
Off-Attenuation Level
10 dB
20 dB
30 dB
Resistor Value
18 kΩ
50 kΩ
150 kΩ
15
Procedure: Short jumpers X103, X107, X108 and X906 (in the
Master section). Remove resistors R1011, R1019, and R1020.
Procedure: Short jumper X114. Remove resistor R1046.
Procedure: Short jumper X115.
Procedure: Short jumper X111.
Procedure: Short jumper X113. Remove resistors R1046 and
R1058.
Procedure: Remove resistors R9088 and R9145. Install new re-
sistor at jumper points X904 and X908.