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1222
SRA
SRA 2422
SRA 3622
Studio Reference Amplifier
User Manual
*TD-000107-00*
TD-000107-00 rev.A
1
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IMPORTANT SAFETY INSTRUCTIONS & EXPLANATION OF SYMBOLS 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 ventilation openings. Install in accordance with QSC Audio Product’s instructions. 8- Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat. 9- Do not defeat th
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TABLE OF CONTENTS INTRODUCTION General Overview..........................................................................................4 Illustrations.............................................................................5 UNPACKING Unpacking and Inspection..................................................................................6 What is Included.............................................................................................6 SETUP Stand-alone Mounting..............
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INTRODUCTION- General Overview QSC’s SRA Series Amplifier Congratulations on your purchase of the SRA (Studio Reference Amplifier)Series power amplifier. To help you obtain the best results from your purchase, we encourage you to carefully review this manual. With information including connections, configuration and operation, it offers many useful guidelines. Building upon QSC’s widely recognized reputation throughout the cinema industry as “The Power Behind the Pictures,” the SRA Series of po
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INTRODUCTION- Illustrations Front Panel (gain control security cover removed) 1- Power switch 4- Channel 1 signal and clip indicators 2- Channel 1 gain control 5- Channel 2 gain control 3- Power “on” indicator 6- Channel 2 signal and clip indicators Note! Amplifiers are shipped with the gain controls set at maximum gain (+29 dB) and with gain control security cover installed. See page 10 for security cover removal and installation information. Rear Panel 11- Channel 2 Speakon output connector 1-
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UNPACKING AND INSPECTION The SRA amplifier is highly durable and carefully packaged. We recommend you inspect the unit carefully after removing it from the packaging, as occasionally there may be damage due to some unfortunate incident during shipment. Report any damage to the shipping carrier. We recommend saving the carton and packing material in case the unit must be shipped back to your dealer, distributor, or service center. Also note: some freight companies consider damage claims without t
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SETUP- Stand-alone mounting (cont’d.) Dimensions shown are useful for non-rack mount installations. Rack Mounting Rack mounting the amplifier Rack mounting is optional. The amplifier fits a 483 mm (19”) width equipment rack. To rack mount the amplifier: 1- Install the rack mount ears (see below and the following page for details). 2- Position the amplifier in the equipment rack and secure all four corners of the front panel using machine screws and washers. The size and thread type of the screws
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SETUP- Rack Mounting Continued, from previous page..... Attaching the rack mount ears: 1- Remove the two screws holding the front panel end cap in place. Use a #2 cross point screwdriver (Phillips). 2- Place the rack mount ear as shown, aligning it so the screws will go back into their original locations. 3- Insert the screws and tighten being sure to keep the rack mount ear properly aligned. 4- Repeat procedure for the other side When installing equipment into a rack, distribute the units evenl
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SETUP- Supporting the rear of the amplifier Supporting the rear of the amplifier If transporting the amplifier in a loaded equipment rack, support the rear of the amplifier using rear rack ears. They are optional and not included with the amplifier. QSC’s Technical Services Group has the rear rack ear kits for sale. The rear ear kit mounts two ways (shown below): - using machine screws to secure the amplifier to the rear ears - using a post and the notch to support the rear. Refer to the instruc
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SETUP- Removing the Gain Control Security Cover Gain Control Security Cover The amplifier is shipped with its gain controls at their maximum setting of +29 dB and a security cover installed to prevent tampering. To adjust gain settings, remove the cover. Reinstall the cover to prevent unintentional changes. Cover retaining tab detail (left) and corre- sponding chassis retaining slot (right). Removing the Security Cover 1- Using a 5/64” (or 2 mm) hex key, remove the cover’s retaining screw and se
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SETUP- Installing the Gain Control Security Cover 4- Gain controls exposed for adjustment. Installing the Gain Control Security Cover 1- Slide the cover into the front panel recess. Push it fully to the right and against the front panel. You should feel the cover’s retaining tabs drop into the slot in the front panel. 2- While lightly pressing the right side of the cover against the chassis, use the hex key tool (inserted into the plate’s screw hole) to slide the cover to the left until the LEDs
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SETUP- Cooling Requirements Cooling Air Inlet and Exhaust Vents The amplifier has a rear-mounted variable-speed fan. Speed is determined by the temperature of the amplifier’s internal heat sink assembly. Cooling air enters the rear of the amplifier and exhausts from the front vents. If mounting in an enclosure, be certain not to restrict airflow. Warm air exhausts through the front panel Cool air is vents. pulled into the rear of the amplifier. Fan Amplifier Equipment Rack Do not obstruct cooli
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SETUP- AC Power Requirements AC Power Verify operating voltage before plugging amplifier into AC mains. Make sure the AC mains voltage is the same as specified on the serial number plate. Do not use a smaller gauge cord than supplied with the amplifier! 120 Volt models are sup- plied with a #14 AWG cordset. 220 Volt models 2 are supplied with 1.0 mm cordset. The serial number plate is affixed to the rear panel, bottom right corner, adjacent the AC cord entry. Do not use improper AC mains voltage
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SETUP- Operating Mode Selection Mode Switches The mode switches are located on the rear panel. The switches are recessed to prevent accidental changes. It is best to set the switches as re- quired before mounting the amplifier in an equipment rack as they may become difficult to access. Change switch positions by sliding the switch left or right. Operate the switches with a small, flat-tip screwdriver or similar tool. Do not use a pencil or other item that could break and fall into the amplifier
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SETUP- Operating Mode Selection: Stereo Stereo Mode Notes: To operate in stereo mode, set switches 4, 5, 6, and 7 to the left position. Input connections: connect one input to CH1 and the other to CH2. Use the XLR or RCA connectors. Output connections: using the binding posts or the Speakon connectors, connect CH1 and CH2 outputs to their respective speakers. Stereo Mode: mode switches 4, 5, 6, and 7 to the left. Biamp Applications- Use Stereo Mode Biamp Notes: Switch settings are the same
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SETUP- Operating Mode Selection: Parallel Parallel Mode In parallel mode, channel 1 and SRA amplifier channel 2 XLR inputs are connected CH1 XLR Input in parallel. Applying an input signal to either XLR input will drive both CH1 Output channels. Each channel still has independent Full range Mode switches loudspeakers gain control, clip limiting, and set for parallel output connection, just like stereo mode. Do not use CH2 input! CH2 input is CH2 Do not use the RCA inputs if connected internally
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SETUP- Operating Mode Selection: Bridge Bridge Mode SRA amplifier In bridge mode, both output channels are interconnected into CH1 Input one, higher power output. The CH1+ XLR or RCA result is one output with about 4 Output times the peak power and about 3 times the sustained power of a Mode switches single channel. set for bridge Do not useCH2 Use CH1’s gain control, clip limiter, Single, high power CH2+ input! CH2 input loudspeaker Output is internally and LF filter. Use channel 1’s XLR or bri
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SETUP- Clip Limiter Clip Limiters The SRA has separate clip limiters for each channel which respond only to actual amplifier clipping. Amplifier clipping generates internal error signals which cause the clip limiter to quickly reduce amp gain and minimize the overdrive. To preserve as much of the program dynamics as possible, limiting occurs only during actual clipping. Each channel has its own clip limiter switch that can be operated independently. Switch 1 operates CH1’s clip limiter and switc
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SETUP- Low Frequency Filter Low Frequency Filters Unless you already have filtering in the signal path preceding the amplifier, use the low frequency filter to protect your speakers from cone overexcursion caused by frequencies below the speaker’s limits. The speaker’s documentation will specify the low frequency limit. Generally, match the frequency selection to your speaker’s low frequency capability. This improves speaker performance by limiting subaudio cone move- ment, making more power a
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CONNECTIONS- Inputs, General Information Audio Input Connections Input connections to the SRA can be made with circuitry inserts a small impedance between the balanced XLR connectors for all operating modes, RCA connector’s “ground” and the chassis ground. or unbalanced RCA connectors for Stereo and Bridge mode. We recommend using the balanced If the mode switches are set for parallel mode, the XLR connectors whenever possible. Unbalanced XLR input connectors are directly wired in parallel. conn
