QSC 1200 - Manual - manualsarea.com

Page 2 - CAUTION; AVIS; Series One Power Amplifier; INTRODUCTION

2 E X P L A N A T I O N O FG R A P H I C A L S Y M B O L S The lightning flash with arrowhead symbol, within anequilateral triangle, is intended to alert the user to thepresence of uninsulated “dangerous voltage” within theproduct’s enclosure that may be of sufficient magnitudeto constitute a risk o...

Page 3 - WARRANTY AND DISCLAIMERS; Warranty and Service Repair Instructions; We will determine if the product is under warranty:; OVERVIEW OF AMPLIFIER

3 I. INTRODUCTION 1.1 WELCOME Thank you for selecting a QSC Series One power amplifier for your audio system. Our goal is to ensure your completesatisfaction with your amplifier purchase. Please do not hesitate to call your QSC Dealer or QSC Audio Products if youhave any service problems or question...

Page 5 - II: BASIC INSTRUCTIONS; UNPACKING AND INSPECTION

5 AMPLIFIER PROTECTION Full Short Circuit, Open Circuit, Over-Temp, Ultrasonic andRF Protection. Stable into reactive or mismatched loads. SPEAKER PROTECTION DC Load Fault Protection3 Second Turn-on, Instant-off Muting COMPLEMENTARY OUTPUT DEVICES 4 8 16 32 POWER SUPPLY Single Transformer with Indep...

Page 6 - QUICK INSTRUCTIONS; Input Connections The input polarity is as follows:

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...

Page 7 - Please refer to Section 3 for more detailed instructions.

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 ...

Page 9 - INPUT CONNECTIONS; resistive dividers and the

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...

Page 10 - Figure 3.34b 3-Pin XLR Balanced Output Connection; Figure 3.35b 3-Pin XLR Unbalanced Output Connection

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...

Page 13 - Mono Bridge Precautions; SPEAKER CONNECTIONS

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...

Page 15 - PROTECTION FEATURES

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...

Page 16 - OPERATIONAL TROUBLESHOOTING; No Sound

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...

Page 18 - IV: SPEAKER PROTECTION; HORN DRIVER PROTECTION; Frequency

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...

Page 19 - RMS Power; USER RESPONSIBILITY

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 ...

Page 20 - V: MAINTENANCE AND SERVICE; OBTAINING SERVICE

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 ...

QSC 1200 - Manual

Table of Contents:

Summary

Other QSC Models