Rogue Audio ZEUS Owner's Manual page 7

triode operation. For loudspeakers that demand very high levels of power,
ultralinear should provide excellent sound and plenty of power.
The triode/ultralinear switch allows the user to operate Zeus in either of the two
modes. In general, the sonic differences are subtle but for a given loudspeaker one
mode is likely to sound better than the other. There is a complex relationship
between the output transformer and the crossover network so try both and see
which one works best in your system. This switch can be operated while the
amplifier is playing but you will hear a small relay noise through the loudspeaker.
Standby Switch:
The Zeus amplifier SHOULD NOT BE LEFT RUNNING WHEN NOT IN
USE. Unlike solid state amplifiers, tube amplifiers should be shut down when
not being used. This will greatly prolong tube life.
A standby switch has been provided for short-term use between listening sessions
so that the amp will remain in a "warmed up " state. If you will not be listening to
the amplifier for more than an hour, it is advised that the amplifier be turned off.
The standby switch lowers the voltage on the tubes and heater filaments to ½ of
normal operating voltage. Some output (distorted) will be heard so the source
material should be turned off when in standby mode.
Tools required: bias tool (provided with amplifier)
The output tubes (the big ones) need to be "biased' with a grid voltage that
controls the flow of electrical current through the tube. Tube biasing on the Zeus
amplifier has been designed to be both simple and effective. On some amplifiers
biasing is done for two or more tubes simultaneously. With this method, the total
current flowing through the group of tubes may be correct, but the current flow
through any individual tube may vary significantly from the optimal value. With
the Zeus amplifier the bias is set individually for each tube so that the correct
operating point is assured. An added benefit to this approach is that, should a
tube fail prematurely, the single tube can be replaced without having to purchase a
matched set. Use the following procedure to set the tube bias:
WARNING – There are dangerous and potentially lethal voltages inside this
amplifier. Do not touch any part of the amplifier other than as described
below. If you are uncertain about any of these instructions, please contact
your dealer and have them bias the amplifier for you.
SETTING THE TUBE BIAS
6