QSC 1100 - Manuals

6 2.27 High voltages can be present on the speaker terminals. Always connect speaker terminals with the power off, anduse heavy gauge cable with no frayed strands or damaged insulation. 2.28 Please be aware that power amplifiers have high power circuitry inside with potential for fire and shock haza...

7 2.39 Operation and Indicators Note that the Gain controls are calibrated in dB. As you turn the Gain down, it takesmore input signal to reach full power, so the Gain should be kept in the upper 12 dB of its range for full power outputfrom normal signal sources. The “0 dB” reference indicates that ...

9 3.12 The Model 1200 uses an internal heat radiator, top ventilation slots, and the faceplate for cooling. The faceplatewill get quite warm in severe usage, but this heatsink system will serve adequately when the amp is used in theopen air. If the amps are mounted in tightly confined racks, we reco...

10 mismatches will result in slight loss of common-mode rejection, but will still have much greater noise rejection thanunbalanced inputs. 3.34 Balanced Inputs For proper balanced-line operation, the cable shield should be connected at the power amplifierend only and kept separate from both signal c...

13 Connect the amplifier input to Ch. 1 only, and use only the Ch. 1 Gain control, which now controls the entireamplifier. Do not feed another input into Channel 2. The Ch. 2 Gain control should be kept off for safety. An8 or 16 ohm speaker load should be connected across the two red speaker termina...

15 3.7 25 AND 70 VOLT SYSTEMS 3.71 Introduction Commercial sound systems commonly use dozens or even hundreds of speakers for sounddistribution. Special methods for connecting and controlling many separate speakers have been worked out bycommercial sound contractors. 3.72 25 Volt lines 25 volt distr...

16 3.83 Thermal Protection In case of blocked ventilation, improper loading or prolonged short-circuit operation, thetemperature of the power transistors can rise to excessive levels. If the temperature of the heat sink rises to 85C,a thermostat will remove power to that channel. Power will be autom...

18 that stage. Assuming that the hiss has not always been there, this indicates defective electronics. Certain special-effects units are rather noisy, so compare with other users. Crackles—defined as a “popcorn” noise. If the crackle persists during pauses in the program material, thisindicates defe...

19 You may have some problems finding the larger value capacitors in the preferred film-type construction. Ifnecessary, several can be paralleled; simply add the individual capacitances together to get the total rating. Youwill probably have to locate non-polar electrolytics for values greater than ...

20 V: MAINTENANCE AND SERVICE 5.1 CLEANING The faceplate and chassis can be cleaned with a soft cloth and mild non-abrasive cleaning solution, such as Windex. Avoidcleaning powders or scrubbing pads, as these will scratch and dull the paint. Be sure to unplug the unit prior to cleaning.Do not apply ...