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Shure Brothers Incorporated
222 Hartrey Avenue
Evanston IL 60202-3696 U.S.A.
Model SCM410/SCM410E User Guide
SCM410/SCM410E
FOUR CHANNEL AUTOMATIC MICROPHONE MIXER
1999, Shure Brothers Incorporated U.S. Patents 4,658,425; 5,297,210
27A8690 (SG) Printed in U.S.A.
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TABLE OF CONTENTS DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 OPERATING PRINCIPLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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DESCRIPTION The Shure Model SCM410/E is a four-channel automatic mi- Each input channel has a two-band equalizer and three logic crophone mixer designed for use in sound reinforcement, au- terminals. The equalizer reduces unwanted low-frequency au- dio recording, and broadcast applications. The SCM410 dra- dio pickup and makes different microphone types—lavaliers, matically improves audio quality in any application where mul- boundary and handheld—sound similar. The logic terminals tiple microp
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REAR PANEL MODEL SCM410 REAR PANEL FIGURE 2 1.Power Connector: Unit is energized when the power cord 4.AUX OUT Phono Connector: Feeds consumer-level audio is plugged into a 100–120 Vac (SCM410) or 220–240 Vac equipment, such as a tape recorder, VCR, or video camera. (SCM410E) power source. Can be internally modified.Refer Not affected by MIC/LINE switch. to the “Internal Modification” section. NOTE: There is no 5.MIC/LINE XLR OUTPUT Connector: Can be set for micro- power On/Off switch on this
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INSTALLATION SUPPLIED HARDWARE 4 rubber feet 10 bracket screws, 6 mm (1/4 in.) 1 rackmount bracket, long 4 rackmount screws, 2.54 cm (1 in.) 1 rackmount bracket, short 4 plastic washers 2 straddle brackets 4 wood screws, 1.25 cm (1/2 in.) RACK MOUNTING The SCM410 is supplied with hardware for mounting one or Dual Mixer (Full Rack) Installation two units to a 19-inch audio equipment rack. The hardware can 1.Place the two mixers side-by-side and connect them with also be used to r
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TABLE-TOP MOUNTING Adhere the four (4) supplied rubber feet to the bottom of the mixer at each corner, as shown in Figure 9. This will keep it from sliding and protect the table surface. ATTACHING RUBBER FEET FOR TABLE–TOP MOUNTING FIGURE 9 FIXED MOUNTING Top Mount Hanging Mount 1.Fasten the straddle brackets to the recessed edges of the 1.Fasten the straddle brackets to the top of the mixer, as chassis, using four (4) bracket screws, as shown in Figure 10. shown in Figure 12. INSTALLING STRADD
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SCM410 CONNECTIONS 1.Connect microphone signal sources to the Channel Input 3.Connect the SCM410 Mic/Line Level Output to the input of connectors, as shown in Figure 14. Use conventional 2-con- mixers, EQs, amplifiers or recorders. ductor shielded audio cables. 4.Connect the power cord to 100–120 Vac (SCM410) or 2.If any condenser microphones are connected, set the +12V 220–240 Vac (SCM410E). phantom power DIP switch to ON. SHURE OR SCM410 CONNECTIONS FIGURE 14 LINKING MULTIPLE MIX
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BASIC MIXER OPERATION 1.Adjust each channel level so that its Overload LED flickers 3.Adjust the Master level control for the required output level, only during very loud speech or noise. as indicated by the output peak meter. The SCM410 is now ready for use. 2.Adjust the Low-Cut and High-Frequency controls adjacent to each Input Gain control so that the microphones sound similar. NOTE: The sensitivity of the Intellimix circuitry may allow some channel gating due to static discharge or electri
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SPECIFICATIONS Measurement Conditions (unless otherwise specified): Line Input LEDs voltage 120 Vac, 60 Hz (SCM410) or 230 Vac, 50 Hz Green on channel activation, red at 6 dB below clipping (SCM410E); full gain; 1 kHz, one channel activated; source Phantom Power 12 Vdc open-circuit through 680 Ω resistors impedances: Mic 150 Ω; terminations: Line/Mic Aux 10 kΩ Operating Voltage Frequency Response (at 1 kHz, channel controls centered) SCM410: 100–120 Vac rated nominal, 50/60 Hz, 50 Hz to 20 kHz
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Replacement Parts Optional Accessories Knob, Master (white) . . . . . . . . . . . . . . . . . . . . . . . 95A8238 Line (Power) Cord, 230–240 Vac (UK) . . . . . . . . 95A8713 Knob, Channel Gain (blue) . . . . . . . . . . . . . . . . . 95B8238 External 50 dB Line Pad . . . . . . . . . . . . . . . . . . . . . . A15LA Line (Power) Cord (SCM410) . . . . . . . . . . . . . . . 95A8762 Service Statement Line (Power) Cord (SCM410E) . . . . . . . . . . . . . . 95A8778 For additional service or parts infor
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ADVANCED FUNCTIONS CAUTION: Use of Advanced Functions is recommended only for qualified audio technicians. LOGIC CONNECTION SPECIFICATIONS The SCM410 logic functions expand the range of installation and control options. Logic can be used for everything from sim- ple cough switches to elaborate computer-controlled room systems. (Shure’s AMS Update publication contains addition- al applications of advanced logic. This publication is available by contacting the Shure Applications Department.) The f
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SUGGESTED LOGIC APPLICATIONS This section contains suggestions on the uses of the Remote Channel-On Indicators SCM410’s logic capabilities. Note that uses of these functions Remote indicators can be used to indicate when a talker’s mi- are not limited to the listed applications. The user is limited only crophone is on. Connect the LEDs and a 5-volt supply to the by imagination and creativity. For additional suggestions and GATE OUT pins (See Figure 22). To avoid switching clicks in solutions to
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Inhibiting Gating for Unwanted Sounds D = 1N4148 MaxBus attempts to activate only one microphone per sound source. Muting a microphone channel prevents its audio from DD + appearing at the mixer’s output. However, the muted micro- phone still communicates with other mic channels via Max- 12 V Bus. A sound source picked up by a muted microphone will not POWER SUPPLY activate other microphones. – Sound sources that may cause unwanted microphone chan- nel activation include: • Heating, ventilation,
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Inhibit Function External Logic Devices For information on the inhibit function, refer to the Internal SCM410 logic levels are directly compatible with TTL and 5V Modifications section. CMOS logic families. Mixer logic may be used with 15V CMOS logic if a pull-up resistor is used with each GATE output. See Remote Volume Control Figure 28. The level of the Aux or Master output can be controlled from an NOTE: For information on logic gate use, refer to the TTL external VCA (Voltage Controlled Amp
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INTERNAL MODIFICATIONS • For Channel modifications, the first character of the refer- WARNING: Voltages in this equipment are hazardous to ence designator indicates the channel number,(i.e., R1027 life. No user-serviceable parts inside. Refer all servicing refers to a Channel 1 resistor, X2001 refers to a Channel 2 to qualified service personnel. jumper, etc.). Modifications affecting the Master section are preceded by a “9” (i.e., X9001). NOTE: • All Channel modifications in this section use Ch
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INSERTING AN INPUT LINE PAD To insert a 40 dB line pad for a given microphone input, remove the resistors specified in the following table. Channel Remove Resistor 1 R1005, R1006 2 R2005, R2006 3 R3005, R3006 4 R4005, R4006 DISABLING THE MASTER LEVEL CONTROL The Master gain control can be disabled to prevent tampering. Procedure: Refer to the following table for gain levels and resistor values. 1. Remove resistor R9203. Master Section Gain Resistance 2. Install new resistor at jumper R9173. -6
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When both MUTE IN and OVERRIDE IN logic are grounded, Procedure: the Override mode will take precedence (as supplied, the 1. Short jumper X1005. MUTE IN takes precedence over OVERRIDE IN). 2. Remove resistor R1087. DEAD ZONE ON MUTE IN DEFEAT As supplied, MUTE IN is intended for use as a momentary Procedure: cough button or privacy function (mute when necessary). Short jumper X1002. However, if the MUTE IN is intended to be used so that the talk- er must unmute microphones to enable speech pic
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This modification is equivalent to shorting one of the channel Procedure: OVERRIDE IN to the LOGIC GROUND pin via the high density Short jumper X1003. DB-15 logic connector. With this modification, a channel is al- ways on. SHORTING MUTE IN TO LOGIC GROUND INTERNALLY This modification is equivalent to shorting a channel MUTE IN Procedure: to the LOGIC GROUND pin via the high density DB-15 logic Short jumper X1004. connector. With this modification, a channel is always muted. DISABLING AUTOMATIC