VTL S-400 II series Owner's Manual page 17

If you are connecting to the power amplifier using single-ended interconnects, connect the preamplifier's RCA/single-
ended channel output to the amplifier's single-ended input, making sure the left channel of the preamplifier is
connected to the left amplifier, and so on.
Step 4: Connect the amplifier to the AC outlet
Before connecting to the AC, make sure that the Power rocker switch on the back of the amplifier is turned OFF.
Locate the 20A IEC power cord included with this unit, and connect the square end of the power cord to the AC
Power inlet located in the back of the amplifier (near the bottom) and the other end of the power cord to the AC outlet
on the wall. The plug should seat all the way into the connector, as loose connections can cause intermittent operation.
Step 5: Select the correct input
Set the Input Select switch on the back of the amplifier to either XLR or RCA, according to the type of interconnect
cable being connected, as shown above.
Warning:
It is critical for proper sonic and noise level performance of this component that it be
properly configured for the correct mode of operation. If a balanced signal is applied to the inputs
the unit must be configured for XLR/balanced operation, and vice-versa.
Step 6. Power on the Preamplifier and source(s)
Power on the preamplifier. Make sure that your preamplifier is either in the mute state or turn its volume to the zero position.
Before turning on the System, make certain that all connections are made firmly, with the
correct channels connected and phase settings, and that all switches are in the correct
position.
Step 7. Turn on the Amplifier
Locate the Power rocker switch at the back of the Amplifier on the bottom right hand corner next to the AC power
inlet. Turn the switch up to the "ON" position. For the first 10 seconds, you should see four dots scrolling on the
display window indicating that the amplifier is checking its internal status and when it is ready to go into the standby
mode, four blue bars"----" will be displayed in the amplifier's numeric Display window, indicating that the amplifier is
now in standby mode ready for the power on command.
Locate the red POWER button on the front panel located beneath the display window in the center of the Amplifier.
Push and release the POWER button once to turn on the amplifier. The blue light above the red POWER button will
start to blink, and the display window indicates the power on countdown sequence, starting from 240.
During the power up countdown period, the amplifier is in MUTEd mode and has no output, as indicated by the red
MUTE light. The amplifier goes through its internal warm-up stage and the output tubes are automatically biased
during this period, until all tubes reach their optimum bias value.
At the end of the power-on countdown period, the POWER light changes to a steady blue and the MUTE light is
turned off, indicating that the unit is now ready to receive signal.
The Mode LED is steady green if the amplifier is in Tetrode mode (red if in triode mode). The default Mode setting is
green for Tetrode mode.
If optimum bias values are not reached by countdown 000 then the mute led will start to blink, and the 000 will stay on
the display until proper bias values are reached, after which time both the 000 display and the MUTE light will be
turned off, indicating that the amplifier is ready to receive signal.
S-400 Amplifier Owner's Manual 13
VTL