Owner’s Manual UF-3 Universal Filter *TD-004031-00* *TD-004031-00* Rev.
UF-3 UNIVERSAL FILTER I. DESCRIPTION The UF-3 is an embedded dual-channel universal filter accessory for use with select QSC power amplifiers. Compatible amplifier models and lines, both current and discontinued, include: • All PLX, two-channel CX, and two-channel DCA models (with a BSC-3 or BSC-5 BusCard installed) • All four-channel CX and DCA models (with a BSC-7 BusCard installed) • PowerLight models PL 1.0, PL 1.0HV, PL 1.4, PL 1.5X, PL 1.6HVX, PL 1.8, and PL 2.
III. PROGRAMMING THE UF-3 The UF-3 circuit board has six 3-pin headers and four SIP resistor network sockets (see Figure 2). All are used for programming the module. The circuitry for the two channels is identical, so the headers and sockets are divided between them: those designated by a three-digit number starting in a “1” (headers J101, J102, and J103; and SIP resistor network sockets RN102 and RN104) are for Channel 1, while those with a three-digit number starting in a “2” are for Channel 2.
Programming the High-Pass Filter and CD Horn Equalization To use either the high-pass filter or the constant-directivity horn equalization, or both, set the jumper on Jx02 across pins 2 and 3, which are the lower two pins on their header. If, however, you do not wish to use either one and want to bypass them instead, set the jumper across pins 1 and 2. To set the corner frequency (at which the output is 6 dB down) of the high-pass filter, choose the appropriate value for RNx04; use the table at right.
Use only these three digits to determine resistance code. Disregard the other numerals and letters. Figure 4—SIP resistor network identification RESISTANCE 270 470 560 1.2K 1.5K 1.8K 2.0K 2.2K 2.7K 3.3K 4.7K 5.6K 6.8K 8.2K 12K 15K 18K 20K 22K 27K 33K 47K 56K 68K 82K 120K CODE 271 471 561 122 152 182 202 222 272 332 472 562 682 822 123 153 183 203 223 273 333 473 563 683 823 124 IV.
Ultrasonic Filter An ultrasonic filter is useful for minimizing RF interference, oscillations, leakage or aliasing from digital devices, and other signals that are too high in pitch to hear but may wreak havoc in an amplifier system. Program settings: 1. Set the jumper on Jx01 to enable the low-pass filter (across pins 2 and 3). 2. Set the jumper on Jx02 to bypass the high-pass filter (across pins 1 and 2). 3.
2-Way Active Crossover This configuration routes the frequencies below a particular frequency to amplifier Channel 1, which shall drive the low-frequency speakers, and the frequencies above to Channel 2, which shall drive the high-frequency speakers. Using the UF-3 as a crossover requires that you drive both amplifier inputs with the same full-band signal. HF Driver Fc Channel 2 Amp Channel 2 Channel 1 Channel 1 SPA-2 LF Driver Figure 9—UF-2 as a 2-way active crossover Program settings: 1.
Multi-way Crossover System The UF-3 allows you to set up 3- and even 4-way systems. Of course, this also requires that you use more than one amplifier and more than one UF-3. The other basic requirement of using the UF-3 as a crossover is that you must feed each amplifier with the same full-range signal and use the UF-3 to filter the signals in the individual channels. Figure 9 depicts an example of a 4-way system.
Tools and materials you will need: Soldering iron Desoldering iron or other suitable desoldering equipment Phillips screwdriver Wire cutters Rosin-core solder CAUTION: • Do not use desoldering braid because it may damage the solder pads on the BusCard or input board, and it also might not adequately remove solder. • The UF-3 contains active components which can be damaged by electrostatic discharge (ESD).
Figure 12—The legacy CX (left) and EX Series (right) input cards Continue preparing the PC board by removing solder from all 22 in-line socket holes. Once this is done, you are ready to install the UF-3. With the input panel facing you and the component side of the UF-3 board facing away from you, carefully insert the header pins of the UF-3 fully into the socket holes. Turn the assembly over and solder the UF-3 in place. Make sure all the header pins are well soldered.
VII. TECHNICAL ASSISTANCE & SERVICE Servicing your QSC product requires a trained and qualified technician. There are no user serviceable components inside, and the danger of electric shock exists. Additionally, some of the components are QSC-specific parts that require QSC replacements. Comprehensive service manuals for most models are available from QSC.
QSC Audio Products, Inc. 1675 MacArthur Blvd., Costa Mesa, California 92626 USA Tel: +1 714 754-6175 Fax: +1 714 754-6174 Web: www.qscaudio.
