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User Manual SMR 821a Mic/Line Program Audio Mixer
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Intended to alert the user to the presence of uninsulated “dangerous voltage” within the product’s enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons. Intended to alert the user of the presence of important operating and maintenance (servicing) instructions in the literature accompanying the product. C CA AU UT TI IO ON N: : Risk of electrical shock — DO NOT OPEN! C CA AU UT TI IO ON N: : To reduce the risk of electric shock, do not remove cover. No
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I IM MP PO OR RT TA AN NT T S SA AF FE ET TY Y I IN NS ST TR RU UC CT TI IO ON NS S W WA AR RN NI IN NG G: : When using electrical products, basic cautions should always be followed, including the following: 1. Read these instructions. 2. Keep these instructions. 3. Heed all warnings. 4. Follow all instructions. 5. Do not use this apparatus near water. 6. Clean only with a dry cloth. 7. Do not block any of the ventilation openings. Install in accordance with manufacturer’s instructions. 8.
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E EN NG GL LI IS SH H ™ The SMR 821a is a professional microphone and line level audio program mixer intended for D De es sc cr ri ip pt ti io on n: : fixed installation applications. This single‚ rack-mount unit is designed to provide high-quality audio performance using versatile control options and a simple user-interface. Engineered from the ground up with the commercial sound systems contractor in mind‚ the SMR 821a includes many features for easy operation‚ installation and servicing. With
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2 3 5 8 10 12 13 1 4 6 7 9 11 14 15 (1) Gain Control F Fr ro on nt t P Pa an ne el l This control may also be referred to as a trim control. It varies the amount of mic preamp gain at the first gain stage. (2) Status LED This bi-color LED illuminates green when a -20 dBu signal is present and red when the signal level is near clipping. (3) Level Control (Channels 1–6) This control adjusts the channel signal level sent to the mix buses. It functions identically on channels 1–6. (4) Level Control
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16 18 21 23 25 27 30 17 19 20 22 24 26 28 29 31 32 33 (16) AC Power Receptacle R Re ea ar r P Pa an ne el l Accepts standard IEC power cable (included). (17) Power Switch Applies power to the SMR™821a. (18) Left‚ Right and Aux Outs Main mix bus balanced outputs. (19) Remote Connector Used to control signal levels of the Left and Right outputs and Stereo Input Select from a remote location. (20) Bus Links Stacking connector for linking multiple SMR™821a mixers. (21) EQ Switch Places the 4-band
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The SMR™821a is designed to be installed in a standard EIA equipment rack. Since the depth of the I In ns st ta al ll la at ti io on n 3 unit is only 8 ⁄4"‚ you can use practically any size rack. Using only a single EIA rack space‚ the SMR 821a includes integral rack mounting ears and does not require any additional hardware for rack mounting…other than rack screws! All connections are made on the rear panel. It is recommended that you provide an additional 4" of clearance between the rear of th
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Stereo Inputs Channels 7 and 8 provide two inputs for each channel. These are intended for stereo use‚ as each input (Left‚ Right) has a fixed assignment to the Left and Right output buses. Additionally‚ a sum of both inputs is fed simultaneously to the Aux output bus. Although you cannot change the distribution of these inputs‚ you can determine if they are stereo or mono. The Mode switch‚ when enabled‚ will sum both connectors‚ feeding both to the Left and Right outputs simultaneously. These c
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Master Bus Output and Link Connections These connections allow you to expand your SMR™821a. The Bus Links connector has 5 pins for combining multiple units. Using a 4-pin conductor‚ shielded cable‚ you can easily connect between two or more units wiring pin-to-pin across multiple SMR™821a mixers. Note: Use only shielded cables. Refer to the following illustrations. Figure 4. Master Output & Bus Link Connections Audio Positive In a linked system‚ the Master mixer’s outputs Audio Negative would be
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External Control Connections The SMR™821a provides a powerful external control option. This feature allows you to configure remote controls for the Left and Right Level controls simultaneously and the Channel 7/8 select function. The Remote operation connector provides a simple way to make these connections. Note: Use only shielded cable. Refer to the following illustrations. Figure 5. Remote Volume Control Connections This example is used to simultaneously control the Left and Right Level Contr
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Configuration Since the SMR™821a is an analog product‚ there is not a lot of configuration to worry about. No software‚ no data cables‚ no networks and no headaches. However‚ there are a few things to remember while you begin to use your new SMR™821a mixer. The SMR™821a is shipped from the factory ready to go. You should be able to follow the steps below and get audio through the unit. Figure 7. The first step is to calibrate your gain settings for the inputs. Each microphone input has a Gain I
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The next step is to configure the many rear panel switches for your applications. Figure 10. Although the unit is shipped from the factory with default switch values‚ you should Input Channel Bus Assign Switches and make sure that these settings are correct for your application. Let’s take a look at Input Connectors each one and describe how it works. First there are the Channels 1–6 Bus Assign Switches (See Figure 10). These switches provide the ability to assign each input to the Left‚ Right
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The SMR™821a offers optional features for specific applications. These options include transformers O Op pt ti io on na al l F Fe ea at tu ur re es s for the microphone inputs and the ability to defeat the functionality of the Channel 7/8 select switch. These options and modifications require access to the inside of the SMR™821a. It highly recommended that the installation of the optional microphone transformers and modification of the Channel 7/8 Select switch be performed by qualified service
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Figure 14. Cutaway of circuit board showing jumper locations for installation of optional microphone transformers. Cut Jumper Here Cut Jumper Here Cut Resistor Here Cut Jumper Here Note: Cuts are typical for each channel where the transformers will be installed. Do not cut these jumpers unless a transformers installed for that channel. BE CAREFUL! 14
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C Ch ha an nn ne el l 7 7/ /8 8 M Mo od di if fi ic ca at ti io on n This modification changes the functionality of the Channel 7/8 front panel select switch and the busing of the audio inputs. When this modification is complete‚ the front panel switch will act as a MUTE switch for all signals connected to the Channel 7 and 8 RCA connectors. In addition‚ both stereo channels (7 & 8) will simultaneously feed the Left‚ Right and Aux output buses. The Select action of the switch is defeated. Refe
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B Bl lo oc ck k D Di ia ag gr ra am m 16 Mute Threshold Level +48V Threshold Detection SIG/ CLIP Optional Transformer LEFT + LEFT OUTPUT LEVEL RIGHT FOUR BAND EQUALIZER CH 1 PAD PREAMP VCA EQ CH 1 AUX + BYPASS I LEVEL - GAIN LEFT LEFT OUTPUT - PRE +48V REMOTE LOW CUT CTRL LEFT RIGHT OUTPUT LEVEL HPF MIC MIX SIG/ Optional L MUTE CLIP Transformer POST + + R MUTE REMOTE RIGHT RIGHT CH 2 RIGHT PAD PREAMP OUTPUT - HPF I CTRL CH 2 AUX VCA LEVEL - GAIN FOUR BAND EQUALIZER RIGHT OUT MUTE L CH 3 R SHD B
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S Sp pe ec ci if fi ic ca at ti io on ns s D Di im me en ns si io on ns s 1.75" (H) x 19" (W) x 8.75" (D) (45mm x 483mm x 222mm) W We ei ig gh ht t 7.4 lbs (3.4 kg) M Mo ou un nt ti in ng g Single EIA Rack Mount C Co on nn ne ec ct ti io on ns s Removable Euro-type connectors for single channel audio inputs‚ outputs‚ bus link and external control. RCA single-ended female for channels 7 and 8 stereo inputs. IEC receptacle for AC power. T Te es st t C Co on nd di it ti io on ns s 120Vac 60 Hz mai
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N No oi is se e Output Signal/Noise (typical) Test Conditions 100 dB All level controls down 84 dB Master level controls nominal Channel level controls down Left Right 80 dB All controls nominal All channels assigned Mic gain minimum 95 dB All level controls down 92 dB Master level control nominal Channel level controls down Aux 81 dB All controls nominal All channels assigned Mic gain minimum G Ga ai in n Mic input range without pad: 10 dB to 60 dB 80 dB max Mic input to output without pad: -10
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E ES SP PA AÑ ÑO OL L ™ ™ La SM MR R 8 82 21 1a a es una mezcladora de audio para señales de línea y de micrófono diseñada para D De es sc cr ri ip pt ti io on n: : aplicaciones que requieren instalaciones permanentes. Esta unidad de un espacio de rack provee gran calidad de audio usando versátiles opciones de control y una interfase fácil de usar. Pensada desde el principio con el contratista de sistemas de audio comerciales en mente, la S SM MR R 8 82 21 1a a incluye muchas características pa
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2 3 5 8 10 12 13 1 4 6 7 9 11 14 15 (1) Control de Ganancia PANEL FRONTAL Este controlaría la cantidad de ganancia de preamplificador de micrófono en este primer paso de ganancia. (2) LED de Estatus Este LED bicolor se ilumina verde cuando hay una señal de -20 dBu presente y rojo cuando el nivel de señal está cerca de saturar. (3) Control de Nivel (Canales 1-6) Este control ajusta el nivel de señal del canal que se envía al bus de mezcla. Funciona de manera idéntica en los canales 1-6. (4) Co
