User manual DOD FX747

[. . . ] Replacement fuses are 13 amps and MUST be ASTA approved to BS1362. Safety Instructions Notice for customers if your unit is equipped with a power cord. The cores in the mains lead are colored in accordance with the following code: Green and Yellow - Earth Blue - Neutral Brown - Live As colors of the cores in the mains lead of this appliance may not correspond with the colored markings identifying the terminals in your plug, proceed as follows: ·The core which is colored green and yellow must be connected to the terminal in the plug marked with the letter E, or with the earth symbol, or colored green, or green and yellow. ·The core which is colored blue must be connected to the terminal marked N, or colored black. ·The core which is colored brown must be connected to the terminal marked L, or colored red. [. . . ] ·This device must accept any interference received, including interference that may cause undesired operation. ·Operation of this unit within significant electromagnetic fields should be avoided. CONDUCTOR L N E LIVE NEUTRAL EARTH GND WIRE COLOR Normal BROWN BLUE GREEN/YEL Alt BLACK WHITE GREEN Warning: If the ground plug is defeated, certain fault conditions in the unit or in the system to which it is connected can result in full line voltage between chassis and earth ground. Severe injury or death can then result if the chassis and earth ground are touched simultaneously. SR Crossover SR823 / SR834 INTRODUCTION The DOD SR834 is a stereo 3-way, mono 4-way crossover, and the SR823 is a stereo 2-way, mono 3-way crossover. These high-quality crossover networks are designed to extract maximum sound quality from your multiamped sound system at a price working musicians can afford. Accurate 24dB/octave Linkwitz-Riley state-variable filters prevent peaks or dips in the output at crossover points, ensuring good driver protection by rolling off crossover frequencies rapidly. A 4-pole, 24dB/Octave Butterworth filter may be electronically inserted at 40 Hz using a switch on the front panel (834 only), and a variable low frequency summed output is available for mono subwoofer applications. The rear panel of the SR834/SR823 is clearly labeled for stereo and mono operation, and all outputs on the SR834 except the mono Low Frequency Sum output include phase switches. ADVANTAGES OF A MULTIPLE AMPLIFIER SYSTEM Multi-amped systems use separate amplifiers for each frequency band, allowing each amplifier to deliver maximum efficiency within a specified range. This method of amplification yields a cleaner overall sound and a significant decrease in the amount of power needed to drive the system to the same levels as a full-range amplified system with more power. The greatest power demands in a sound system are made by the low frequencies of the program material. This is because music and voice signals contain mostly low frequency information, and low frequency drivers are generally less efficient than high frequency transducers. If below 180Hz is desired, press the ÷10 switch** on the rear panel. If the desired frequency is below 180 Hz, the ÷10 switch must be engaged (LED indicator lit). If the desired frequency is above 180 Hz, the Range switch must be disengaged (LED indicator off). When the ÷10 switch is engaged, the frequencies marked around the LOW/MID (LOW/HIGH for SR823) frequency control are divided by 10. In other words, if the LOW/MID (LOW/HIGH for SR823) frequency is set at 250Hz and the range switch is engaged, the actual crossover frequency is 25Hz. When using the crossover in stereo mode, use the lower frequency markings to set the MID/HIGH crossover point. WARNING: BEFORE PRESSING THE ÷10, LF SUM OR STEREO/MONO SWITCHES, LOWER THE OUTPUTS OF YOUR POWER AMPLIFIERS TO AVOID DAMAGE TO DRIVERS AND LOUDSPEAKERS. 4 SR Crossover · Connect the outputs of the crossover to the appropriate amplifiers. Check to see that all crossover level controls are set to -12, and that both gain controls are set to 0 dB. · Send a broadband signal into the crossover and slowly bring up the LOW level control. SR834: Apply power to the mid frequency amplifier and turn up the MID level control to the desired level. SR834/SR823: Finally, apply power to the high frequency power amplifier and bring up the HIGH level control to the desired level. [. . . ] THE PHASE INVERSION SWITCHES ARE MECHANICAL SWITCHES AND SHOULD ONLY BE CHANGED WHEN THE POWER AMPLIFIER FOR THAT OUTPUT IS OFF. Turning down the level controls will not prevent transients from appearing at the outputs when changing the phase switches while the crossover is on. STEREO OPERATION USING A MONO SUBWOOFER This mode of operation provides: SR834: Channel 1 and Channel 2 high frequency outputs, Channel 1 and Channel 2 mid frequency outputs, and one summed low frequency output. SR823: Channels 1 and 2 high frequency outputs and one summed low frequency output. [. . . ]