Using The Df Switches; Df Switch Settings - VTL S-400 II series Owner's Manual

Using the DF switches

The variable DF is an adjustable Damping Factor control that allows the user to adjust the output
impedance of the amplifier.
The two DF switches, one per channel, are located on the deck of the amplifier below the 12BH7 tubes.
Please remove the top cover of the amplifier to access the switches. Always mute the amplifier prior to
changing the setting of the DF switches.
There are three possible settings of the DF switches: Low, Medium, and High. Please check to make sure
that the switches in both channels are in the same position. There is no right or wrong position, and the
switches are provided to allow adjustment to better suit the listener's taste and to offer better control to
loudspeakers that may need it.

DF Switch Settings

1. LOW: Both switches are positioned towards the left and right side of the amplifier. This is the
lowest damping factor setting, the least loudspeaker control, and most natural sound.
S-400 Amplifier Owner's Manual 27
VTL