dbx Pro 480 - Manual (Page 113)

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The 480, 481 and 482 DriveRack™ units offer you the option of changing the input gain level settings. There are 3 hard-
ware configurable gain settings. They are: +14 dBu, +22 dBu and +30 dBu. For these cases, use the following pro-
cedure to change the gain level settings. Please be advised however, that once the gain level has been changed from
the factory settings, the output meters will no longer be calibrated correctly.
To change the gain level, move the jumpers to the pins that are marked with the desired gain setting
1) First, ground yourself prior to opening the DriveRack™ chassis to prevent ESD damage.
2) Open the chassis by removing five screws on each side of the chassis and the top two center screws on the rear panel,
as well as the top center allen screw located on the front panel
3) Locate the jumper block shown in the illustration below:
4) Set the jumpers to the desired input and output gain settings. Note that to change settings on inputs 3 and 4 and out-
puts 5-8 of the 480 and 482, the top board must be removed.
5) Once the desired settings have been made, replace the chassis lid.
481 Top Board
Input Jumpers Output Jumpers
+22dBu
Ch1
+30dBu +30dBu
Ch1
Ch2
Ch1
Ch2
+14dBu Ch2
+14dBu
+22dBu +22dBu
Ch3
+30dBu +30dBu
Ch3
Ch4
Ch3
Ch4
+14dBu Ch4
+14dBu
+22dBu
+14dBu
+22dBu
+30dBu
+14dBu
+22dBu
+30dBu
+14dBu
+22dBu
+30dBu
+14dBu
+22dBu
+30dBu
+14dBu
+22dBu
+30dBu
+14dBu
+22dBu
+30dBu
+14dBu
+22dBu
+30dBu
+14dBu
+22dBu
+30dBu
480 and 482 Top Board
Input Jumpers
Output Jumpers
+22dBu
Ch1
Ch1 Ch2 Ch3 Ch4
+30dBu
+14dBu
+14dBu +22dBu +30dBu +14dBu +22dBu +30dBu +14dBu +22dBu +30dBu +14dBu +22dBu +30dBu
+22dBu
Ch2
NOTE: Inputs 3 and 4 are located directly beneath inputs 1 and 2 on the underside of the board.
Outputs 5-8 are located directly beneath Outputs 1-4 on the underside of the board.
+30dBu
+14dBu
CAUTION: These servicing instructions are for use by qualified service
personnel only. To reduce the risk of electric shock, do not perform any
servicing other than that contained in the operating instructions unless you
are qualified to do so. Refer all servicing to qualified service personnel.
Disconnect mains power before servicing.
A.8 Gain Level Jumpers
Appendix A
DriveRack ™
DriveRack™ User Manual 105