Toa VX-2000SF - Ground Lifting

Chapter 8: INSTALLATION AND SETTING PROCEDURES (HARDWARE)
5. VP-3154, VP-3304 AND VP-3504 POWER AMPLIFIERS
8-41
5.2. Ground Lifting
HumnoisemaybegeneratedbyagroundloopaccidentallycreatedthroughthePAlink’saudioinput.
In this case, the ground loop can be cut by setting the ground lift, which can be performed on the pc board of
PA link/BGM input board.
Step 1. Remove the top panel. (See Step 1 on
p. 8-40.)
Step 2. Take out the PA link/BGM input board to be set for ground lift.
Remove2screwsatthecorrespondingchannel’sboardontheamplier’srearwhileholdingtheinternal
PC board as show below.
Thegurebelowshowsanexampleofremovingchannel1’sboard.
PA link/BGM input board
PA link/BGM input board
Step 3. Cut the jumper J2 on the pc board.
Step 4. Replace the PA link/BGM input board and the top panel in the reverse procedures of removal.
Amplifier’s rear
BGM input PA link/BGM input board
J2 (Ground lifting)
Cut to make ground lifting.
Viewed from the parts mounting side