User manual QSC AUDIO MODEL 1100

[. . . ] Series One v v v v Model 1100 Model 1200 Model 1400 Model 1700 Owner's Manual ® A U D I O *TD-000027-00* Rev. C 1 Series One Power Amplifier Operation Manual TABLE OF CONTENTS I: INTRODUCTION 1. 1 Welcome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. 4 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EXPLANATION OF GRAPHICAL SYMBOLS The lightning flash with arrowhead symbol, within an equilateral triangle, is 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 humans. 3 3 3 4 The exclamation point within an equilateral triangle is intended to alert the users to the presence of important operating and maintenance (servicing) instructions in the literature accompanying the product. II: BASIC INSTRUCTIONS 2. 1 Unpacking and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . 6 III: OPERATION 3. 1 Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] Octal Module Installation Peel away the protective cover and plug in the module, observing correct alignment of the guide post in the middle. The input bypass switches for that channel must be turned off (See Section 3. 5). Certain other switches may need to be set in accordance with the type of module and combination of channels desired. Input to the module occurs automatically through the amplifier's input jacks. 3. 43 3. 44 3. 5 INPUT SWITCHES AND MONO BRIDGING 3. 51 Input Programming Switch An 8-pole input programming DIP switch will be found on the rear panel of the amplifier. The switch functions are as follows: (move levers up to turn on, down for off) Switches 1, 2: Bypass the Octal Socket for Channel 2. Turn "off" when an octal accessory is plugged in (see the instructions with the octal accessory). Switches 3, 4: Connects the output from an octal accessory plugged into Channel 1 to both amplifier channels. Turn "off" for normal operation or for using separate octal accessories. If octal accessories are used, the inputs (not the outputs) of both accessories will be combined. This may be used in place of a Y-cord for feeding a common input signal to both channels. 3. 52 Mono Bridging Most stereo amplifiers have a method of combining both channels in series to give the combined power into a single load. This is a way to fully use both channels when only a single speaker is driven. To engage the bridged-mono mode of the Model 1100, a slide switch must be set through a hole in the bottom of the amplifier. Due to the danger of touching live terminals inside the amplifier, BE SURE TO REMOVE ALL POWER AND DISCONNECT THE AC PLUG before resetting the switch. In accordance with the label on the bottom, set the switch towards the front for bridged-mono use, and towards the rear for normal stereo use. To engage the bridged mono mode on the Model 1200, 1400, or 1700, there is a separate slide switch located below the barrier strip inputs on the rear panel. Follow the directions on the label to engage the switch in the "Bridge" position. 12 Connect the amplifier input to Ch. An 8 or 16 ohm speaker load should be connected across the two red speaker terminals, using the red terminal of Ch. 1 as the "+" or "hot" terminal, the red terminal of Ch. Minimum load impedance is 8 ohms, which will be the equivalent, to the amp, of 4 ohms per channel. If a fourohm load is used, the amp will have to work very hard and may overheat. Be sure there is no ground or other circuit connected to either side of the speaker cable. [. . . ] Extreme cases such as lead guitar work may require speaker ratings of twice the RMS power of the amplifier to withstand the full peak power. The average power of signals where some attempt is made to prevent overdrive distortion will be less than the amplifier RMS rating; how much less depends on the dynamic range and headroom allowance. In live-performance situations where feedback and high-energy artists can push the system to its limits, it would probably be wise to match the RMS ratings of the speakers and the amplifiers. 4. 5 POWER LIMITING There are several ways to limit the power to safe levels without operator intervention. Fuses can be added which will blow in case of overloads; the problem is to select a fuse with the correct time lag and overload characteristics to match the speaker limitations. [. . . ]