QSC Audio owner manual Installing the UF-3 on a BusCard, Installing the UF-3 on an input card

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). Be sure to practice standard ESD precautions and always ground yourself and your workstation before handling exposed circuit cards.

•Preparing the input board for installation of the UF-3 involves removing solder from feed-through holes on a two-sided circuit card. Excessive heat can easily 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 following procedure.

•Please contact the QSC Technical Services Group if you feel you might not be qualified to perform the installation yourself.

•One last warning: damage caused by an improper installation will void the warranty.

Installing the UF-3 on a BusCard

It is easier to configure and install the UF-3 Universal Filter with the BusCard removed from (or not yet installed in) the amplifier.

Turn off the amplifier and unplug it from the AC. Allow about 10 minutes or longer for the internal voltages to bleed down before you open the amplifier chassis.

If the UF-3 is to be installed on a BSC-6 BusCard (for the PowerLight 3.4, 3.8X, or 4.0), snap off the breakaway section of the UF-3 circuit board by flexing it at the pre-scored line.

Make sure you insert the UF-3 card on the correct side of the BusCard. Insert the UF-3 fully into the holes on the BusCard. Solder all 22 pins to the BusCard; make sure you don’t create any solder bridges. Then install the BusCard in the amplifier; see the BusCard instructions for details.

Installing the UF-3 on an input card

Turn off the amplifier and unplug it from the AC. Allow about 10 minutes or longer for the internal voltages to bleed down before you open the amplifier chassis. Disconnect all cables from the amplifier’s input panel.

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 11.

Begin the installation by locating and removing the screws securing both the upper blank and lower input panels to the rear side of the chassis (two screws on each mini panel). The upper blank panel will simply drop off when its screws are removed.

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.

Next, desolder and remove the wire jumper pairs W305/W306 and W405/W406 (W303/W304 and W403/W404 on MXa Series amplifiers). Under where the jumpers were are two rows of solder pad holes, one with 10 holes and another with 12. These make up the “Mini-Slot,” in which the UF-3 mounts. See Figure 12.

Input card

C H 1 LOW IMPEDANCE	AUDIO TRANSFORMER		C H 1
DIR . OUTPUT	0	7 0 10 0 ISOL . OUTPUT

B R I D G E	7 0 V	2 5 V
	10 0 V
M O N O

C H 2	12	10	8
14			6
18			4
2 4			2
		- d B	0

L E V E L

C H 2 I N P U T C H 1			12	10	8	C H 1
						6
G R O U N D	ST E R E O		14
			18			4
			2 4			2
				- d B	0
I N P U T	PA R A L L E L	B R I D G E		L E V E L

C H 2 LOW IMPEDANCE	AUDIO TRANSFORMER		C H 2
DIR . OUTPUT	0	7 0 10 0 ISOL . OUTPUT

B R I D G E	7 0 V	2 5 V
	10 0 V
M O N O

Figure 11—Location of the input card

8