QSC SRA 1222 - Manuals

5 INTRODUCTION- Illustrations Front Panel (gain control security cover removed)1- Power switch 2- Channel 1 gain control 3- Power “on” indicator Rear Panel1- DataPort connector 2- Channel 1 RCA input connector 3- Channel 2 RCA input connector 4- Channel 1 XLR input connector 5- Channel 2 XLR input c...

6 The SRA amplifier is highly durable and carefully packaged. We recommend you inspect the unit carefullyafter removing it from the packaging, as occasionally there may be damage due to some unfortunateincident during shipment. Report any damage to the shipping carrier. We recommend saving the carto...

7 Rack Mounting 1- A #2 size cross point (Phillips) screwdriver. 2- The rack mount ears included with you SRA amplifier. To attach the rack mounting ears, you will need: Dimensions shown are useful for non-rack mount installations. SETUP- Stand-alone mounting (cont’d.) Continued, top of next page......

8 SETUP- Rack Mounting Dimensions for rack mount installations. Note: Some dimensions are taken from the front surface of the rack rail. Continued, from previous page..... 1- Remove the two screws holding the front panel end cap in place. Use a #2 cross point screwdriver (Phillips). 2- Place the rac...

9 SETUP- Supporting the rear of the amplifier If transporting the amplifier in a loaded equipment rack, support the rear of the amplifier using rearrack ears. They are optional and not included with the amplifier. QSC’s Technical Services Group hasthe rear rack ear kits for sale. The rear ear kit mo...

10 SETUP- Removing the Gain Control Security Cover Gain Control Security Cover The amplifier is shipped with its gain controls attheir maximum setting of +29 dB and a securitycover installed to prevent tampering. To adjust gain settings, remove the cover. Reinstallthe cover to prevent unintentional ...

11 SETUP- Installing the Gain Control Security Cover Installing the Gain Control Security Cover 1- Slide the cover into the front panel recess. Push it fully to the right and against the frontpanel. You should feel the cover’s retainingtabs drop into the slot in the front panel. 2- While lightly pre...

12 SETUP- Cooling Requirements The amplifier has a rear-mounted variable-speedfan. Speed is determined by the temperature ofthe amplifier’s internal heat sink assembly. Cooling air enters the rear of the amplifier andexhausts from the front vents. If mounting in an enclosure, be certain not torestri...

13 SETUP- AC Power Requirements AC Power Verify operating voltage before pluggingamplifier into AC mains. Make sure the ACmains voltage is the same as specified on theserial number plate. Do not use a smaller gauge cord than suppliedwith the amplifier! 120 Volt models are sup-plied with a #14 AWG co...

14 SETUP- Operating Mode Selection Stereo Mode Mode Switches The mode switches are located on the rear panel.The switches are recessed to prevent accidentalchanges. It is best to set the switches as re-quired before mounting the amplifier in anequipment rack as they may become difficult toaccess. Ch...

15 Biamp Applications- Use Stereo Mode 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 CH1and the other to CH2. Use the XLR or RCAconnectors. •Output connections: using the binding postsor the Speakon connectors...

16 Parallel Mode SETUP- Operating Mode Selection: Parallel In parallel mode, channel 1 andchannel 2 XLR inputs are connectedin parallel. Applying an input signalto either XLR input will drive bothchannels. Each channel still has independentgain control, clip limiting, andoutput connection, just like...

17 Bridge Mode In bridge mode, both outputchannels are interconnected intoone, higher power output. Theresult is one output with about 4times the peak power and about 3times the sustained power of asingle channel. Use CH1’s gain control, clip limiter,and LF filter. Use channel 1’s XLR orRCA input. O...

18 SETUP- Clip Limiter CLIP LIMITER ON: To turn the limiter on, slide the switch to the right (Sw.1: Ch.1, Sw.10: Ch.2). CLIP LIMITER OFF: To turn the limiter off, slide the switch to the left. Clip Limiters The SRA has separate clip limiters for eachchannel which respond only to actual amplifiercli...

19 SETUP- Low Frequency Filter Channel 1’s low frequency filter is operated by switches 2 and 3. Channel 2’s filter is operated by switches 8 and 9. FILTER ON: To turn the filter on, slide the switch to the right (Sw.2: Ch.1, Sw.9: Ch.2). FILTER OFF: To turn the filter off, slide the appropriate swi...

20 Audio Input Connections CONNECTIONS- Inputs, General Information Input connections to the SRA can be made withbalanced XLR connectors for all operating modes,or unbalanced RCA connectors for Stereo andBridge mode. We recommend using the balancedXLR connectors whenever possible. Unbalancedconnecti...

21 XLR Connector Pinout CONNECTIONS- Inputs: XLR and RCA Connector Pinouts RCA (phono plug) Connector Pinout Balanced Unbalanced pin 2 pins 1 and 3 Jumper pin 2 pin 1 pin 3 Signal (+) Ground Daisy Chain Example (parallel mode only) All amplifiers being daisy chained must be in parallel mode. Input s...

22 Connecting the Outputs to the Loudspeakers There are two basic speaker connectionconfigurations for the SRA amplifier. Stereoand parallel modes use two separate outputconnections (two loudspeaker loads). Bridgemode uses one output connection (one loud-speaker load). Use either the binding post or...

23 CONNECTIONS- Outputs: Binding Posts Using the Binding Posts The binding posts support several connection methods;banana plugs, spade lugs, or direct wire connection.European models do not support the use of bananaplugs. If using banana plugs, plug into the binding postdirectly. If using spade lug...

25 CONNECTIONS- Outputs: Speakon connectors Speakon Outputs The Speakon connectors offer quick, reliable connection and disconnection of the speakers.Although more expensive than banana or spade-lug style speaker cable termination, the speed,convenience, and reliability make Speakon use popular with...

27 CONNECTIONS- Outputs: Speakon Biamp Application Biamp Operation In biamp, one channel is used for lows, while theother channel is used for highs. It requires the useof signal processing equipment between thesource material and the amplifier. Always test thesystem at the lowest practical power lev...

28 CONNECTIONS- Remote on/off (remote trigger) Remote turn-on and turn-off capability is provided by the remotetrigger jacks on the rear panel. Remote trigger can be operated bytwo methods, 12 Volt DC or contact closure (switch, relay). The INand OUT jacks can be used interchangeably as they are wir...

29 CONNECTIONS- Remote on/off (remote trigger) 12 VDC Type 12 Volt DC Remote Trigger For 12 Volt DC remote triggeroperation, use a mono (2terminal) 3.5 mm mini-plug.Do not use a stereo (3 termi-nal) plug. Connect a suitable two-conductor cable to the plug.Connect the tip of the plug tothe + (or posi...

31 CONNECTIONS- DataPort DataPort is located on the left side of the rear panel. A typical DataPort application shown with a program- mable QSC DSP-4 signal processor. The PC is required only for programming the DSP-4 and is not required to remain connected. The DataPort is a QSC-specific connection...

32 LED indicators. USE- Front Panel Controls and Indicators Gain Controls A gain control adjustment is provided for eachchannel. The voltage gain of the amplifier (in dB)is marked around each control. Rotating the control clockwise increases the gainapplied to the signal. Rotating the control counte...

33 APPLICATION EXAMPLE- 7.1 Surround 7.1 Surround Application The block diagram, atright, shows how SRAamplifiers might beconnected in a 7.1home theater applica-tion. The connectionsshown are simplifiedso as to convey thesignal routing scheme.All amplifiers shownare operated in stereomode. Amplifier...

34 TROUBLESHOOTING The amplifier “cuts-out” when I really crank it up (intermittent operation)- • Make sure the AC power source is rated for the required current! Avoid using extension cords! If required, use only the shortestpossible 10-gauge heavy-duty extension cords. • If the AC power source is ...

35 TROUBLESHOOTING I am using the amp for a subwoofer application and it sounds “rubbery”, what’s up?- • Verify that the Clip Limiters are OFF. Why? The Clip Limiter is set to respond as quickly as possible after clipping is detected. Onlow frequency material, this may be perceived as a “rubbery” ef...

36 SRA1222 SRA2422 SRA3622 Output Power: (watts per channel, stereo/parallel mode) 8 ohms, 20Hz to 20kHz, 0.03% THD 200 425 725 4 ohms, 20Hz to 20kHz, 0.05% THD 350 725 1100 2 ohms, 1kHz, 1.0% THD 600 1200 1800 Output Power: (watts, bridge mode) 8 ohms, 20Hz to 20kHz, 0.10% THD 750 1550 2400 4 ohms,...

37 SPECIFICATIONS- SRA Series Specifications subject to change without notice! ALL MODELS Voltage gain: 28× (29 dB) Controls: Front- AC switch, Recessed Ch. 1 and Ch. 2 gain knobs Rear- DIP switch (Ch. 1: clip limiter on/off, LF filter on/off,LF filter freq select—20 or 50 Hz; Ch. 2: clip limiter on...

38 Disclaimer QSC Audio Products, Inc. is not liable for any damage to speakers, or any other equipment that is caused bynegligence or improper installation and/or use of this amplifier product. QSC Audio Products 3 Year Limited Warranty QSC Audio Products, Inc. (“QSC”) guarantees its products to be...