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Anleitung Zusammenfassung
Description The MPC-XU is a dual-channel universal crossover filter accessory for use with JBL MP. and MPA power amplifiers. The MPC-XU is user configurable to fulfill these functions. . active crossove. . bandpass filte. . subsonic filte. . ultrasonic filte. The MPC-XU allows independent filtering o. the two audio channels. The choices are. . high-pass filtering (selection of 19 frequencies. . low-pass filtering (selection o. 17 frequencies. . bandpass filtering (selection o. any combination of the high-pass or low-pass frequencies. Each channel has an electronically balanced input and bypassable low-pass and high-pas. sections. Each filter circuit uses a 4-pole (24 dB/oct) Linkwitz-Riley alignment. An alternative to the MPC-XU, the MPC-X100 is preset at 100 Hz for use only as . subwoofer crossover. The MPC-XU installs onto the amplifier.s input card, where its settings are not easily acces. sible to the user. This makes the MPC-XU ideal for installed or rental sound systems, since i. practically eliminates the danger of unauthorized tampering with crossover setting o. incorrect crossover output connections, as well as the loudspeaker damage that may resul. from such user tampering. Installing the MPC-XU involves soldering a 10-pin and a 12-pin header into correspondin. holes on the input card, a process that only qualified technical persons should attempt. W. recommend that you enlist an authorized JBL service center to perform the task. See th. installation section o. this manual for more information. Figure 1 shows a block diagram of one channel o. the MPC-XU. Programmable Linkwitz-Riley Low-Pass Filter Programmable Linkwitz-Riley High-Pass Filter Figure 1. One channel of the MPC-XU *TD-000082-00* TD-000082-00 Rev. B 2 II. Installation CAUTION: The MPC-XU contains active components which can be damaged by electrostatic discharge (ESD). Be sure to practice standard ESD precautions, and always ground yourself and your workstation before handling exposed circuit cards. Installing the MPC-XU requires PC board soldering skills. Only qualified service technicians should attempt it. Any authorized JBL service center can perform the installation. The MPC-XU installs on the amplifier input board of any JBL MPA or MPC amplifier. Tools needed: Soldering iron .-inch (6.3 mm) nutdriver Phillips screwdriver Wire cutters Rosin-core solder Desoldering iron or other suitable desoldering equipment (Do not use desoldering braid; it can damage the solder pads on the input board and might not remove solder adequately.) CAUTION: Preparing the input board for installation of the MPC-XU involves removing solder from feed-through holes on a 2-sided circuit board. Excessive heat can damage the solder pads you will be working on. Proper equipment and experience with desoldering delicate PC board circuitry is essential to successfully perform the procedure. Damage caused by improper installation is not covered under warranty. 1 Turn off the amplifier and disconnect the AC power cord from the AC source. Disconnect all cables from the amplifier.s input panel. 2 Position the amplifier so the rear of the chassis is facing you. The input panel is located on the left side of the rear panel. See Figure 2a. CH1 CH2 CH1 CH2 BRIDGE MONO BRIDGE MONO LOW IMPEDANCE LOW IMPEDANCE DIR. OUTPUT DIR. OUTPUT ISOL.OUTPUT ISOL.OUTPUT AUDIO TRANSFORMER AUDIO TRANSFORMER 70V 70V 25V 25V 100V 100V 0 70 100 0 70 100 -dB 0 -dB 0 10 8 10 8 6 6 4 4 24 2 24 2 18 18 14 14 STEREO 12 CH2 INPUT CH1 12 CH2 CH1 LEVEL PARALLEL BRIDGE LEVEL GROUND INPUT 3 Locate and remove the screws securing both the upper blank and the lower input panels to the rear side of the chassis (2 screws on each mini panel). The upper blank panel will simply drop off when its screws are removed. 4 Gently pull the lower input panel out from the amplifier. Once it is removed, you will notice a ribbon cable connecting the input PC board to the amplifier. Disengage the locking wing clamps on the ribbon header and carefully remove the ribbon head from the socket on the board. Now the input panel assembly is completely free from the amplifier. 5 Desolder and remove the wire jumper pairs indicated in Figure 2b or 2c. 6 Under where the jumpers were located, you.ll find two rows of solder pad holes.one with 10 holes and another with 12 holes. Remove the solder from all 22 holes. 7 With the input panel facing you and the component side of the MPC-XU board facing away from you, carefully insert the header pins of the MPC-XU fully into the socket holes. Turn the assembly over and solder the MPC-XU in place. Make sure all the header pins are well soldered. Visually inspect for cold solder joints and verify that you have sufficient clearance to re-install the ribbon connector on the top side of the assembly. Finish by trimming the MPC-XU header pins as required. Figure 2a. The input panel’s location on the rear panel of the amp Figure 2b. The input panel (MPC) Input panel Wire jumpers: W303/304 and W403/...