Model PX. Paragraphic Equalizer With Electronic Crossover. Owner s Manual A.R.P.A. OF AMERICA CORP. MADE IN MODESTO, CA U.S.A.

Transcription

1 Model PX Paragraphic Equalizer With Electronic Crossover Owner s Manual A.R.P.A. OF AMERICA CORP. MADE IN MODESTO, CA U.S.A.

2 Contents Introduction 2 Installation Instructions 3 PX Equalization Modules 5 Input Gain Adjustment 6 Technical Assistance 7 Manufacturing 8 1

3 Introduction The ZAPCO model PX is a programmable four-band equalizer and 12dB per octave electronic crossover housed in an attractive anodized aluminum chassis designed to be mounted either indash or under-dash. The PX is comprised of two pieces: the PX Main containing all of the audio circuitry and PSi, an isolated power supply that provides the audio circuitry with + or - 15V supply rails. A master volume control and four filter control knobs are readily accessible on the PX front panel. The filter controls have a maximum boost or cut of 18dB at either extreme of rotation. Independent left and right channel INPUT GAIN adjustments are made via access holes in the lower left hand corner of the front panel. A main power ON indicator and three OVERLOAD indicators are provided to aid in system troubleshooting and calibration. Signal inputs and outputs are made to the rear of the unit by way of gold plated RCA connectors. The back panel also contains the controls for the electronic crossover. The crossover frequency is continuously variable in a range of 70Hz to 1.6 khz by using the CROSSOVER FREQUENCY control pot. Separate LOW / HIGH PASS OUTPUT LEVEL controls are provided for system balancing. An auxiliary FULL RANGE output is provided for possible use with full range satellites or 600 ohm earphone. The modular phone DC POWER INPUT connector at the upper right hand corner of the back plate is used to connect the PX Main to the external power supply, the PSi. The power supply, model PSi, is a highly efficient and compact switching power supply that provides the PX Main with all necessary operating voltages. An extra modular output connector is provided for use with an additional PX. A fifteen foot interconnecting cable is supplied to allow for remote mounting of the supply. The PSi is used to trigger on/off operation of the PX Main. A plug-in barrier strip is used to terminate the necessary +12V, GND and TURN ON connections to the unit. 2

4 Installation Instructions Careful thought and planning is a must in installing a mobile audio system. Extra consideration is always recommended when routing the signal cables to guard against injecting noise into the system. NEVER mount any piece of ZAPCO equipment in the engine compartment. Avoid routing signal and power cables together in one bundle; isolate these lines on opposite sides of the vehicle if at all possible. Keep the above thoughts firmly in mind when determing a suitable mounting location for the PX Main. It may be mounted underdash using the supplied bracket or in-dash using the four countersunk mounting holes in the front panel. If mounting indash, allow sufficient slack in the cabling to and from the unit as access to the back panel controls may be necessary in fine tuning the crossover point or output levels. The PSi can be mounted virtually anywhere within the vehicle that is free from moisture. Its compact design, plug-in barrier strip and power connections enable the installer to mount the unit in potentially hard to reach locations. While the stock, fifteen foot cable length should be taken into consideration when determing the mounting location, custom length cables can be ordered from A.R.P.A. of America Corp. The plug-in barrier strip is used to terminate all necessary power and turn-on connections. The connector is polarized and will only plug into the unit one way. Care must be taken to insure that each connection terminates to the proper position on the plug! Note that when looking at the screw side of the plug-in module all connections are reverse of the label on the top of the unit. BEFORE INSTALLING ANY PIECES OF EQUIPMENT: LIFT THE NEGATIVE (GROUND) BATTERY LEAD. 3

5 The +12 INPUT must be connected to the PSi through an AGC 2A in-line fuse. Although the PSi is internally fused, an additional fuse should be placed as close to the 12V source as possible to protect system wiring in the event of short to chassis ground from a pinched power input lead. The PSi GND connection should be securely attached to the car chassis ground using a suitable lug to terminate the connection to bare metal. Bare wires do not make adequate, permanent connections. The PSi TURN ON can be connected to any switched 12V sources such as a tape deck, power antenna," or CD switched to 12V output. ONLY wire sizes between AGW 12 and 22 gauge should be used when making these connections. Strip 1/4 inch of insulation from the end wire, insert into the proper position in the barrier strip and tighten screw securely. It is always recommended that wiring be securely terminated BEFORE APPLYING VOLTAGE. This will eliminate the possibility of damage to the vehicle wiring by shorting +12V to chassis ground. PX TURN ON PX power up is initiated by application of +12V to the TURN ON terminal located on the plug-in barrier strip of the PSi. Note that the PSi will not turn on unless the power cable is securely connected to the DC INPUT connector on the rear of the PX Main. The POWER indicators on the PSi and the PX should both illuminate upon power up. 4

6 PX Equalization Modules The equalizer section of the PX Main features plug-in modules that enable the user to select both the center frequency and bandwidth of the four front panel FILTER controls. The stock PX comes equipped with the following modules: Filter # Frequency Q-(Bandwidth) 1 35Hz Hz Khz Khz 1.3 These stock filters are found to be effective in most applications and are a good starting point in the process of equalizing the typical system. If it is determined that there are acoustic problems that the stock filters do not effectively cover, there are 120 additional filters from which to select. Contact Technical Assistance at the factory for ordering information. Please specify center frequency and Q when ordering additional filter modules. NOTE: Q is a numeric expression of the effective width of a filter. In general the larger the Q the narrower the effective bandwidth. For example, a filter with a Q of 4.5 would be a spike filter effecting a very narrow band of frequencies while a filter such as the stock #3 centered at 1.1Khz with a Q of 0.6 effects virtually the entire midrange. 5

7 Input Gain Adjustment The pre-amp circuit built into the PX is capable of 26dB of gain. Separate left and right channel INPUT GAIN adjustments are made via two access holes in the lower left hand corner of the front panel. Adjustments to the INPUT GAIN may be necessary to match the source (TAPE DECK, TUNER, OR CD) output level to the input sensitivity of the system amplifiers. If this adjustment is set too low, the source may distort before the system is able to achieve full power. If the INPUT GAIN is adjusted too high, the internal circuitry of the PX and/or system amplifiers may distort. Three OVERLOAD indicators located on the front panel of the PX are supplied to aid in the gain adjustment procedure. Each of these are WARNING indicators and should NOT illuminate with any degree of regularity once the system gains have been properly adjusted. The red indicator labeled PRE is calibrated to illuminate when the internal circuitry of the PX is within 1dB of clipping. The yellow indicators labeled LO & HI are calibrated to ZAPCO power amplifiers with an input sensitivity of 2.5V RMS and indicate the onset of amplifier clipping. Insert tape or compact disc recorded at high level into the source unit. If the source unit has a balance control, ensure that it is set to center. Set the PX filter controls flat (white strip on control knobs completely vertical). Using a small plastic screw driver included with the PX adjust the INPUT GAIN trim pots fully counterclockwise. These trim pots are 20 turn pots and will ratchet at the end of their throw. Turning each pot more than 20 turns counterclockwise (or until ratcheting can be heard) will ensure that left & right channels are matched before the gain adjustment procedure begins. If the source has a volume control, set it from approximately 1/2 to 3/4 full output. With the PX volume control rotated completely counterclockwise, begin by turning only one INPUT GAIN pot clockwise (count the number of turns) until PRE indicator flashes, rotate 1 to 2 turns counterclockwise or until flashing ceases. Rotate the other INPUT GAIN trim pot the same number of turns as the first. Turn up the 6

8 PX volume control and adjust LOW & HIGH OUTPUT levels to achieve an overall system balance. Minor INPUT GAIN adjustments may be necessary to achieve left/right balance or for louder tapes or compact discs. Setting filter controls at a high boost position may also cause the PRE indicator to flash, necessitating reduction in INPUT GAIN. If LO or HI indicators flash, adjust LOW or HIGH OUTPUT level controls accordingly. Technical Assistance Should you experience a problem with your PX, please contact the dealer that sold you this product. If your dealer is unable to solve your problem, you may contact the factory customer service department directly. Phone: (209) Monday-Friday 8am-5pm Pacific time Fax: (209) If you need to return this product for repair, please call the factory for a return authorization number. We will ask you for information which will include your name, return shipping address, daytime phone number, model and serial number, and a detailed description of your problem. A photocopy of your original purchase receipt is necessary to determine warranty status and should also be included. Once we issue you a return authorization number, please write it in a highly visible area on the package. Zapco will not accept any packages that do not have a valid return authorization number clearly marked on the outside of the package. Send all repairs to: A.R.P.A. of America Corp. Attn: Service Department 413 S. Riverside Drive, Suite D Modesto, CA

9 Manufacturing This product is designed and manufactured in the USA. The following operations are ENTIRELY performed in our Modesto, California plant. 1. PC Board insertion The components are inserted into American made printed circuit boards. 2. PC Soldering The printed circuit board assembly is wave soldered. 3. Testing The PC board is 100% tested to design specs. 4. Extrusion Machining American made aluminum extrusion is cut and machined to precise tolerances. 5. Assembly The product is assembled. 6. Final Test Every product is tested with the highest quality audio test equipment to meet or exceed their published specifications. 7. Inspection and final packaging. *Many companies claim that their products are built in the USA, but only a few of the above steps are actually performed in America. Many of these companies only do the final assembly, with steps 1-4 being done outside the USA. 8

10 A.R.P.A. of America Corp. 413 S. Riverside Drive, Suite D Modesto, CA (209) Fax (209) PX Rev. G 12/96