User manual

9.3 Tube Change
Tube changes are only to be undertaken by authorized service personnel. If power tubes
with different values then the original ones are to be installed, then the amplifier must be
re-biased before operation can be resumed. The amplifier uses a three circuit bias
system. It is quick and easy to accomplish biasing, but involves removing the chassis and
use of specialized equipment for measuring currents inside the amplifier. Only trained
professionals should attempt this procedure.