Shure | SCM262 | User guide | Shure SCM262 User guide

Model SCM262 User Guide
SCM262
STEREO MIXER
MÉLANGEUR STÉRÉO
STEREOMISCHER
MEZCLADORA ESTEREOFONICA
MIXER STEREO
©2012 Shure Incorporated
27A15638 (Rev. 2)
Printed in U.S.A.
! IMPORTANT SAFETY INSTRUCTIONS !
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READ these instructions.
KEEP these instructions.
HEED all warnings.
FOLLOW all instructions.
DO NOT use this apparatus near water.
CLEAN ONLY with dry cloth.
DO NOT block any ventilation openings. Install in accordance with the manufacturer's instructions.
DO NOT install near any heat sources such as radiators, heat registers, stoves,
or other apparatus (including amplifiers) that produce heat.
DO NOT defeat the safety purpose of the polarized or grounding-type plug. A
polarized plug has two blades with one wider than the other. A grounding type
plug has two blades and a third grounding prong. The wider blade or the third
prong are provided for your safety. If the provided plug does not fit into your outlet, consult an electrician for replacement of the obsolete outlet.
PROTECT the power cord from being walked on or pinched, particularly at plugs,
convenience receptacles, and the point where they exit from the apparatus.
ONLY USE attachments/accessories specified by the manufacturer.
12.
USE only with a cart, stand, tripod, bracket, or table
specified by the manufacturer, or sold with the
apparatus. When a cart is used, use caution when
moving the cart/apparatus combination to avoid
injury from tip-over.
13.
UNPLUG this apparatus during lightning storms or when unused for long periods of
time.
REFER all servicing to qualified service personnel. Servicing is required when the
apparatus has been damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus
has been exposed to rain or moisture, does not operate normally, or has been
dropped.
DO NOT expose the apparatus to dripping and splashing. DO NOT put objects filled
with liquids, such as vases, on the apparatus.
The MAINS plug or an appliance coupler shall remain readily operable.
The airborne noise of the apparatus does not exceed 70dB (A).
Apparatus with CLASS I construction shall be connected to a MAINS socket outlet
with a protective earthing connection.
To reduce the risk of fire or electric shock, do not expose this apparatus to rain or
moisture.
Do not attempt to modify this product. Doing so could result in personal injury
and/or product failure.
Operate this product within its specified operating temperature range.
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This symbol indicates that dangerous voltage constituting a
risk of electric shock is present within this unit.
This symbol indicates that there are important operating and
maintenance instructions in the literature accompanying this unit.
WARNING: Voltages in this equipment are hazardous to life. No user-serviceable parts inside. Refer all servicing to qualified service personnel. The
safety certifications do not apply when the operating voltage is changed from the factory setting.
WARNING: This product contains a chemical known to the State of California to cause cancer and birth
defects or other reproductive harm.
SHURE SCM262
DESCRIPTION
The SCM262 Stereo Mixer is designed for restaurants, classrooms,
corporate training, aerobics classes, and other situations where a paging/
public announcement system is combined with background music or other program material.
The Shure Model SCM262 is a stereo mixer intended for sound reinforcement applications that integrate microphones with consumer stereo
products. It incorporates two active-balanced microphone inputs with
three unbalanced stereo aux level inputs.
FEATURES
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Designed to combine paging with background music.
One active-balanced, XLR microphone input channel.
One active-balanced XLR microphone and 1/4-in. TRS line input channel.
Three STEREO INPUT channels
Stereo AUX level OUTPUTs
Stereo MIC/LINE OUTPUTs
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BASS and TREBLE tone controls on the master output.
1/2-rack chassis.
12 V phantom power for condenser microphones.
Internal power supply.
Removable power cable.
Ducking function (defeatable).
Jukebox mute function (defeatable).
FRONT PANEL
2
1
3
� MIC Channel Gain Controls, 1-2. Control the gain levels of
the MIC channels and LINE IN 2 (MIC 2).
4
5
6
� POWER Indicator. Lights up to indicate when the unit is
plugged in and receiving power.
� STEREO Channel Gain Controls, 1-3. Control the gain levels from CD players, juke boxes, VCRs, or other consumer
stereo equipment connected to the STEREO inputs.
NOTE: The SCM262 does not have a power switch. To turn
the unit off, unplug the power cord or use an external power
strip with a switch. However, it can remain plugged in as it uses
very little power when idle.
� BASS and TREBLE Controls. Control the boost/cut of the
low- and high-frequency of the shelving filters.
� POWER Switch
NOTE: Country dependent
� MASTER Gain Control. Allows adjustment of the overall output gain.
REAR PANEL
1
2
3
4
5
6
7
� Power Connector. Accepts 100-120 Vac (SCM262) or 220240 Vac (SCM262E).
� Left/Right STEREO INPUTS, 1-3. These phono jacks are
stereo inputs for connection to consumer stereo devices.
� Left/Right MIC/LINE Output Connectors. These 1/4-in. connectors are stereo, balanced outputs for use with professional
audio equipment. Controlled by DIP switch.
� MIC Channel 2 INPUT.
Microphone channel 2 has two
available inputs. There is a 1/4-in. connector for balanced/
unbalanced line-level connections, or an XLR connector for
balanced mic-level connections.
� Left/Right AUX Output Connectors. These phono jacks are
stereo, unbalanced outputs for use with consumer stereo
equipment.
� MIC Channel 1 INPUT. This is an XLR connector for balanced mic-level connections.
� DIP Switches. These allow you to adjust the SCM262 for
specific applications. See DIP Switches.
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UP
2
3
4
5
6
7
DIP
SWITCH
FUNCTION
POSITION
UP (default)
DOWN
1
LEFT OUTPUT MIC/LINE
Line
Mic
2
RIGHT OUTPUT MIC/LINE
Line
Mic
3
MIC 1 DUCKING
Off
On
4
MIC 2 DUCKING
Off
On
5
DUCKING LEVEL
–
–20 dB
6
STEREO 3 JUKEBOX MUTE
Off
On
7
12 V PHANTOM
Off
On
MIC
MIC
ON
ON
-20
ON
ON
1
OFF
OFF
LINE
LINE
OFF
OFF
-∞
DOWN
L OUTPUT
R OUTPUT
MIC 1 DUCKING
MIC 2 DUCKING
DUCKING LEVEL (dB)
ST. 3 JUKEBOX MUTE
12 V PHANTOM
DIP SWITCHES
LEFT/RIGHT OUTPUT MIC/LINE: DIP switches 1 and 2 adjust the left
and right outputs for line- or mic-level operation.
MIC 1/MIC 2 Ducking: When ducking is on, the SCM262 will automatically lower the gain of all STEREO inputs when someone is speaking into
one of the microphones.
DUCKING LEVEL: Adjusts the amount of STEREO channel gain reduction when ducking is activated.
STEREO 3 JUKEBOX MUTE: This DIP switch turns the Juke Box
Mute feature on or off. When on, any source connected to STEREO 3 will
mute STEREO 1 and 2 inputs.
PHANTOM POWER: When in the down position, this switch activates
a 12 V phantom power source for condenser microphones. Phantom
power does not affect the operation of balanced, dynamic microphones,
so one can be connected to the SCM262 in combination with a condenser
microphone.
APPLICATIONS
so the talker can be heard more clearly. Once the talker is finished, the
music resumes.
General Application
This is a general setup for most situations which require the combined
use of professional microphones and consumer stereo equipment. Using
this general setup, there are several other options available for further adjusting the SCM262 for your sound system. See the diagram on the facing page.
1. Turn all gain controls counterclockwise.
2. Connect L/R STEREO INPUTS of the SCM262 to the L/R stereo
outputs of the desired stereo audio equiment (CD players, VCRs,
televisions, juke boxes, etc.).
3. Connect microphone(s) to the MIC INPUTS on the SCM262.
4. For microphones which require phantom power, such as condenser microphones, place DIP switch 7 in the down position
(phantom power on).
5. Connect the L/R outputs of the SCM262 to the L/R inputs of the
amplifier.
NOTE: Use a microphone with an ON/OFF or pushbutton
switch for the Paging with Ducking Application. A microphone
without a switch will false-trigger, causing unwanted
interruptions in the program material.
1. Connect the SCM262 to the sound system as described in General Application.
2. Set DIP switch 3 or 4 to the down position to activate ducking for
microphone channel 1 or 2, respectively.
3. Set DIP switch 5 position. The Down position sets the ducking so
that the program sound is lowered 20 dB when someone uses a
microphone. The Up position sets the ducking so that the program sound is muted when someone uses a microphone.
Jukebox Mute Application
In this application, designed primarily for Jukeboxes, any sound
source connected to the STEREO 3 channels will automatically mute any
sound coming over the STEREO 1 and 2 channels. This way, a CD player can be playing music, and then when someone plays a song on the
Jukebox, the SCM262 will automatically mute the CD player channels
and switch to the Jukebox. STEREO 1 and 2 channels will remain muted
for about 30 seconds after program material is finished, to allow the jukebox time to move on to the next song.
1. Connect the SCM262 to the sound system as described in General Application.
2. Connect the L/R audio outputs of the jukebox to the L/R inputs of
STEREO 3.
NOTE: If you are using a consumer stereo amplifier, use the
AUX OUTs. If you are using a professional audio power
amplifier, use the LINE OUTs. The MIC/LINE and AUX
OUTPUTs can be used simultaneously to feed two separate
amplifiers.
6. Apply power to the mixer by connecting the supplied power cable
between the power connector on the mixer and the appropriate
AC power supply. The green POWER LED will illuminate to indicate that the mixer is powered on.
*NOTE: The SCM262 has no power switch. It is designed to
be plugged into a power strip which supports the whole sound
system. A typical power strip will have a power switch, so that
when the power strip is powered on, the SCM262 is powered
on.
NOTE: This feature is designed especially for use with
jukeboxes, but will work for any equipment connected to
STEREO 3.
*Power Switch, country dependent.
3. Set DIP Switch 6 to the down position (Jukebox Mute on).
Paging with Ducking Application
NOTE: If the ducking application is used in conjunction with the
Jukebox Mute application, then activated microphones will
mute or duck the STEREO 3 input.
With Ducking on, the SCM262 will automatically sense when someone
is talking into one of the microphones and lower the volume of the music
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CONNECTIONS
MIC INPUT 2
WIRELESS MICROPHONE SYSTEM
MIC INPUT 1
MICROPHONE
AUX INPUTS
AUX INPUT 3
JUKEBOX
AUX INPUTS
TELEVISION
CD PLAYER
OR
AM/FM RECEIVER
L
OR
R
VCR
TAPE DECK
R
R
L
L
POWER SUPPLY
R
L/R AUX OUTPUTS
L/R MIC/LINE
OUTPUTS
VIDEO CAMERA
L
OR
PROFESSIONAL
AUDIO POWER
AMPLIFIER
OR
CONSUMER
STEREO
AMPLIFIER
R
OR
L
VCR
OR
TAPE DECK
LOUDSPEAKERS
LOUDSPEAKERS
7
INTERNAL MODIFICATIONS
WARNING! Voltages in this equipment are hazardous to life. No user-serviceable parts
inside. Refer all servicing and modifications to qualified service personnel.
DISASSEMBLY
To remove MIC 2/LINE 2 from the left outputs, remove R910. To remove MIC 2/LINE 2 from the right outputs, remove R911.
To access the printed circuit board (pc board) for internal modifications, use the following steps:
1. Unplug the power cord.
2. Remove the knobs and retainer nuts from the front panel.
Low-Cut Filter
To eliminate the 80 Hz, low-cut filter, remove resistor R501 (mic 1), or
resistor R519 (mic 2). Place a 10 to 33 F capacitor in X501 (mic 1) or
R502 (mic 2). The polarity of the capacitor does not matter.To change the
frequency of the low cut filter, remove resistor R501 (mic 1) or R519 (mic
2), and place the proper capacitor into X501 (mic 1) or X502 (mic 2) to get
the desired corner frequency.
The following tables list the low-cut frequency corners for some of the
most common capacitor values:
3. Remove the two screws at each bottom corner of the front panel.
4. Remove the four screws at each corner of the back panel.
5. Slide the back panel and pc board out from the rear of the chassis.
Capacitor
Value
.033 F
.047 F
.068 F
.1 F
.22 F
CAUTION: When reassembling the SCM262, DO NOT
OVERTIGHTEN the knob retainer nuts. Use a minimal amount
of force to secure the nut (0.6-0.8 Nm (5-7 inlb)). Damage to
the internal components will result if too much force is used.
Corner
Frequency
803 Hz
564 Hz
390 Hz
265 Hz
120 Hz
Capacitor
Value
.33 F
.47 F
.68 F
1.0 F
2.2 F
Corner
Frequency
80 Hz
56 Hz
39 Hz
26.5 Hz
12 Hz
Ducking Depth
This modification adjusts the level of ducking depth attenuation of the
input channels when ducking is activated.
The aux ducking depth may be changed by removing resistor R213
and inserting a resistor into jumper X202. Use the following tables to determine the proper resistor value for the desired ducking depth.
Mono Mixer Modification
This modification allows all the inputs to be mixed to a single mono signal sent over both the left and right outputs.
Short jumper X203.
Phantom Power Disable
Ducking
Depth
6 dB
9 dB
15 dB
20 dB
24 dB
29 dB
This modification disables the phantom power per channel.
To disable the phantom power from mic 1, remove resistor R121. To
disable the phantom power from mic 2, remove resistor R122.
15 dB Mic Preamplifier Pad
When a microphone has an extremely high signal, getting the desired
gain might be difficult -- a small turn of the gain control might change the
sound from a whisper to deafeningly loud. This modification adds a 15 dB
Mic preamplifier pad to allow more accurate gain adjustment with extremely high microphone signals.
Remove R160 (mic 1) or R183 (mic 2).
Resistor
Value
4,000 
5,000 
7,500 
10,000 
12,000 
15,000 
Ducking
Depth
36 dB
42 dB
47 dB
50 dB
55 dB
Resistor
Value
20,000 
25,000 
30,000 
33,000 
40,000 
Ducking Threshold
This modification adjusts the threshold for activating the ducking circuit.
The ducking threshold can be raised or lowered by first removing resistor R333, and then placing a resistor (R) at jumper X303. To lower the
ducking threshold, use a resistor value (R) less than 2k ohms. To raise
the ducking threshold, use a resistor value (R) greater then 2k ohms.
Hard Panning MIC Channels
To remove MIC 1 from the left outputs, remove R912. To remove MIC
1 from the right outputs, remove R913.
8
INSTALLATION
SUPPLIED HARDWARE
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•
2. Attach the short rackmount brackets to the outsides of the combined units with eight (8) of the bracket screws.
4 rubber feet. For stand-alone installation.
1 rackmount bracket, long. For half-rack (single unit) installations.
1 rackmount bracket, short. For half-rack (single) or dual-mount installations.
2 straddle brackets. For dual-mount or fixed installations.
12 bracket screws, 1/4-in. (6 mm). For securing the brackets
to the chassis.
4 rackmount screws, 1 in. (2.5 cm). For mounting the unit in
a rack.
4 plastic washers. For use with the supplied rackmount
screws.
4 wood screws, 1/2 in. (1.25 cm). For fixed installations
3. After attaching the brackets, mount the unit in an equipment rack
using the supplied rackmount screws and plastic washers.
Bracket Screw
Rackmount Screw
Wood Screw
STAND-ALONE INSTALLATION
RACKMOUNT INSTALLATION
1. Adhere the four (4) supplied rubber feet to the bottom of the unit
at each corner. This will keep it from sliding and protect the table
surface.
The SCM262 can be mounted as a single unit or dual-mounted with either another SCM262 or another Shure half-rack unit such as the
SCM268 or DFR11EQ. Attach the rackmount brackets using one of the
following methods:
Single unit (half-rack) installation:
1. Attach the short and long rackmount brackets to the SCM262 with
eight (8) of the supplied bracket screws.
FIXED INSTALLATION
To permanently affix the SCM262 above or below a table, shelf, or
counter top, use the following steps:
1. Fasten the straddle brackets to the recessed edges of the chassis
using four (4) bracket screws.
Top mount: Fasten the straddle brackets to on the bottom of the unit
Hanging mount: Fasten the straddle brackets to the top of the unit.
Dual-mounted installation:
2. Fasten the straddle brackets to the surface using the four (4) supplied wood screws.
1. Connect the two units together side-by-side using two (2) straddle
brackets. The brackets should straddle the recessed edges on on
the top and bottom of each chassis. Fasten them using eight (8)
bracket screws.
NOTE: Be sure to use both straddle brackets-one on the top
and one on the bottom.
TOP MOUNT
HANGING MOUNT
9
SPECIFICATIONS
Measurement Conditions (unless otherwise specified):Tone controls
centered; Line voltage 120 Vac, 60 Hz (SCM262) or 230 Vac, 50 Hz
(SCM262E); full gain; 1 kHz, one channel activated; source impedances:
Mic 150 ; Line/Aux 40 , terminations: Line/Mic/Aux 20 k
Ducking
Mic channels 1 and 2 Levels .................................... –20 dB or – dB
Activation time ............................................................. 10 ms (typical)
Mic Deactivation time ........................................................ 2 s (typical)
Jukebox Mute Deactivation Time .................................... 30 s (typical)
Phantom Power
Frequency Response (Ref 1 kHz, channel and master controls
centered)
12 Vdc open-circuit through 680  resistors
Operating Voltage
MIC/LINE Inputs: 150 Hz to 20 kHz 2 dB
AUX Inputs: 20 Hz to 20 kHz 2 dB
SCM262: 100—120 Vac, 50/60 Hz, 60 mA
SCM262E: 220—240 Vac, 50/60 Hz, 30 mA
Low-Cut Filter (Microphone inputs only)
Temperature Range
3dB down at 80 Hz, 6 dB/octave
Operating...............................................–7 to 49 C (20 to 120 F )
Storage .................................................–29 to 74 C (–20 to 165 F)
Voltage Gain (typical, controls full clockwise)
Overall Dimensions
Output
Input
Mic
Line
Aux
Low-impedance mic
(150 )
32 dB
72 dB
60 dB
Line
–9 dB
31 dB
19 dB
Stereo
–5 dB
35 dB
23 dB
43 x 218 x 162 mm (1.72 x 8.60 x 6.37 in.)
Net Weight:1.1 kg (2 lbs, 5 oz)
Certifications
SCM262: UL, cUL listed by Underwriters Laboratories.
SCM262E: Conforms to European Union directives, eligible to bear CE
marking; Certified to EN 60 065; meets European Union EMC Immunity
Requirements (EN 50082-1: 1992, EN 50082-2: 1992)
Inputs
Conforms to European Regulation (EC) No. 1275/2008, as amended.
Impedance
Input
Designed
for use with
Actual
(typical)
The CE Declaration of Conformity can be obtained from Shure
Incorporated or any of its European representatives. For contact
information please visit www.shure.com
Input
Clipping Level
Mic (XLR)
<600 
1.4 k
–16 dBV
Line
<10 k
155 k
+24 dBV
Stereo
<2 k
21 k
>28 dBV
Output
Designed for
use with
Actual
(typical)
Output
Clipping Level
The CE Declaration of Conformity can be obtained from:
ww.shure.com/europe/compliance
Authorized European representative:
Shure Europe GmbH
Headquarters Europe, Middle East & Africa
Department: EMEA Approval
Jakob-Dieffenbacher-Str. 12
75031 Eppingen, Germany
Phone: 49-7262-92 49 0
Fax: 49-7262-92 49 11 4
Email: info@shure.de
Outputs
Impedance
Mic
> 600 
3
–22 dBV
Line
>5k 
300 
+18 dBV
Aux
10 k
1.5k 
+5 dBV
Replacement Parts
Knob, Master (blue) ............................................... 95B8752
Knob, Channel Gain (white)................................... 95A8752
Line (Power) Cords:
SCM262: 100—120 Vac (US/Canada) ............. 95B8762
SCM262E: 220—240 Vac (EU)......................... 95B8778
Fuse:
SCM262 (5x20 mm, 250V,
100mA, time delay) ............................................ 80Z730
SCM262E (5x20 mm, 250V,
40mA, time delay) .............................................. 80M258
Hardware Kit .......................................................90AW8100
Link Bars (Bracket) ................................................ 53B8443
Single Mount Bracket............................................. 53A8484
Dual Mount Bracket .............................................. 53E8484
Optional Accessories
Line (Power) Cord, 230—240 Vac (UK) ................. 95A8713
Service Statement
Total Harmonic Distortion
<0.25% at +4 dBu output level, (through 22 Hz—22 kHz filter; MIC Input
1 and Master at center, all other controls full counterclockwise)
Equivalent Input Noise (150  source; A-Weighted)
–128 dBV
Output Noise (channel controls full counterclockwise,
A-Weighted)
Master full counterclockwise .................................................. –95 dBV
Master full clockwise .............................................................. –59 dBV
Common Mode Rejection
>70 dB at 1 kHz
Polarity
All inputs to all outputs are non-inverting.
Overload and Shorting Protection
Shorting outputs, even for prolonged periods, causes no damage.
Microphone inputs are not damaged by signals up to +10 dBV; Line and
Aux inputs by signals up to +28 dBV
For additional service or parts information, please contact Shure's
Service department at 1-847-600-8699. Outside the United States,
please contact your authorized Shure Service Center.
Equalization
Bass (Low-frequency shelving,
corner frequency at 250 Hz)  6 dB
Treble (High-frequency shelving,
corner frequency at 4 kHz)  6 dB
10
United States, Canada, Latin
America, Caribbean:
Shure Incorporated
5800 West Touhy Avenue
Niles, IL 60714-4608 USA
Phone: 847-600-2000
Fax: 847-600-1212 (USA)
Fax: 847-600-6446
Email: info@shure.com
www.shure.com
©2011 Shure Incorporated
Europe, Middle East, Africa:
Shure Europe GmbH
Jakob-Dieffenbacher-Str. 12,
75031 Eppingen, Germany
Phone: 49-7262-92490
Fax: 49-7262-9249114
Email: info@shure.de
Asia, Pacific:
Shure Asia Limited
22/F, 625 King’s Road
North Point, Island East
Hong Kong
Phone: 852-2893-4290
Fax: 852-2893-4055
Email: info@shure.com.hk
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