Installation and Maintenance Manual
For 25 Vrms line-operated speakers, connect them directly to the balanced signal output of the 300VSC.
Connect the speakers in parallel to terminals TB1-4 and TB1-5 of terminal block TB1 on the 300VSC.
Unlike the unbalanced line output, this output is not switched.
IMPORTANT: Use the balanced signal output only if there are no SelecTone system devices connected
to the unbalanced signal output (across TB1-1 and TB1-2).
Unbalanced Line Application
See Figure 3. For existing SelecTone systems using the 300CK Connector Kit, use the unbalanced signal
outputs on the 300VSC. A 300CK Connector Kit is required to connect a 300GC, 300GCX, 300X,
302GC, 302GCX, 302X or 50GC to the unbalanced signal lines. The 300CK properly terminates the
signal lines to the amplifier in the 300GC, 300GCX, 300X, 302GC, 302GCX, 302X and 50GC. Connect
the blue wire on the 300CK to the
300CK to the
Connecting a Low-Level Audio Output
The 300VSC also has a 1-volt peak-to-peak audio output that can be coupled to the audio input of
another amplifier. This low-level output is available across terminals TB1-1 and TB1-2. It can also be
connected to an analog fiber optic transmitter so that audio can be transmitted over a fiber-optic link in
an electrically noisy environment.
12
Figure 2 Model AM25CK connections (balanced line)
300GC
AM25CK
SIG COM
SIG HI
wire from the 300VSC.
Figure 3 Model 300CK connections (unbalanced line)
300GC
300CK
YEL
TERMINAL BLOCK (TB1)
ON REAR OF 300VSC
Model 300VSC-1 and Model 300VSC-1044SB SelecTone Command Units
300GC
AM25CK
4
5
SHIELDED TWISTED-PAIR
SIGNAL LINE TO ADDITIONAL
SELECTONES
TERMINAL BLOCK (TB1)
ON REAR OF 300VSC
wire from the 300VSC. Connect the yellow wire on the
300GC
300CK
BLU
YEL
1
2
SHIELDED TWISTED-PAIR
SIGNAL LINE TO
ADDITIONAL SELECTONES
COM
SIG
HI
290A7324
BLU
290A7318