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MAINTENANCE
Chassis Care:
Although your VAC chassis and faceplate are extremely durable, their finish can be
scratched, chipped or damaged if improperly treated. Cleaning with a soft, damp cloth while
the amplifier is switched off and unplugged should restore the finish to its original lustre.
Never clean this component with harsh or caustic cleansing agents.
When shipping your unit, be certain to wrap the amplifier in the cloth, tissue or plastic wrap
in which it was originally packaged. Given the high gloss of the lacquered finish, make sure
there are no ridges or sharp surfaces in those parts of the cloth which contact the faceplate.
Use of a coarser cloth or failure to otherwise protect the faceplate may result in damage to
the finish. VAC is not responsible for cosmetic damage resulting from improper care or
packing.
Installing New Tubes:
Original Equipment Replacement tubes are available from VAC. These tubes ensure your
Sigma Preamplifier will meet or exceed all factory performance specifications.
DANGEROUS VOLTAGES EXIST WITH THIS COMPONENT. YOU MUST FOLLOW
THESE STEPS TO PROTECT YOUR SAFETY.
Before replacing tubes, all power must
be turned off. Unplug the power cord from the wall, and remove all audio interconnect
cables. Wait 15 minutes before removing the top cover. Install the new tubes fully firmly in
their sockets, taking care to make sure that pin pattern corresponds to holes in tube socket.
Reinstall the top cover before reconnecting the unit.
NEVER INSTALL OR OPERATE THIS UNIT WITHOUT ALL COVERS IN PLACE.
In the event that trouble is encountered, check all signal, speaker and power connections.
If the problem persists, follow all safety precautions stated earlier in this section, and check
that all tubes are correctly seated in their sockets. If possible, try another tube. If the problem
persists, please consult your VAC dealer or contact the factory directly.
