JBL Professional MPC-XU User Manual

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III. Programming the MPC-XU

The MPC-XU board has four switches, six 3-pin headers, and four SIP resistor network

sockets (see Figure 3). All these are used for programming the module. The circuitry for the

two channels is identical, so the switches, headers and sockets

are divided between them: those designated by a 3-digit

number starting in a 1 (switches S101 and S102, headers J101,

J102 and J103; and SIP resistor network sockets RN102 and

RN104) are for Channel 1, while those with a 3-digit number

starting in a 2 are for Channel 2. The following instructions

will use an x in place of  the first digit, except where a specific

channel reference is necessary.

Setting input operating mode on amplifier or input card

The input board or accessory on which the MPC-XU is installed has provisions—switches or

headers—for setting the operating mode of the amplifier. In the signal flow, the MPC-XU is

located after these switches or headers, so its operation is affected by the mode setting.
Stereo or Parallel Mode Operation—If  the amplifier is to be used in stereo or parallel

modes, configure both channels of the MPC-XU accordingly.
Bridged Mode Operation—If  the amplifier is to be used in bridged mono mode, bypass

Channel 2 of the MPC-XU and use only Channel 1’s input and processing.

NOISE SHIELD

TAB

#4-40 NUT

CH. 1 GAIN CONTROL

NOISE SHIELD

INPUT PANEL PCB

8 If  you need to make any adjustments to the MPC-XU settings or if you need to record

them, do so now, because the MPC-XU will be inaccessible once the noise shield is

installed and the input panel is re-installed into the amplifier chassis. See Section III,

“Programming the MPC-XU,” below.

9 Using a ¼-inch (6.3 mm) nutdriver, remove the outer 4-40 nut from the stud in the panel

mounting bracket, next to Channel 1’s gain control potentiometer. Place the noise shield

over the circuit board of the MPC-XU (Figure 3) and bend the grounding tab down so its

hole goes over the stud. Re-install the nut, and tighten it securely (Figure 4).

10 Reconnect the ribbon cable to the input board connector. Press the locking clamp wings

of  the connector closed. You will feel them snap into place.

11 Carefully reposition the input board/MPC-XU assembly into the amplifier chassis and

secure it by fastening the two mounting screws. Make sure the screws are tightened snugly,

but do not over-torque them. Re-install the upper blank panel.

Installation of the MPC-XU is now complete, and the amplifier is now ready to be installed

into the system.