Mad Professor OLD SCHOOL 21RT Owner's Manual

Do not try to open the amplifier chassis – there are no serviceable
parts. Only a qualified service technician should remove the chassis.
Do not expose the amplifier to rain, moisture, or any kind of liquids.
Never use the amplifier in wet or damp conditions.
TUBES ARE HOT. DO NOT TOUCH DURING OR SHORTLY AFTER
OPERATION.
Plug the amp only to correct AC voltage, the voltage can be changed
to 100/120 or 230/240V from the back panel of the amp. The fuses
must be changed to correct rating if voltage is changed.
The fuses should be replaced only with identical ratings and only
when the power cord has been disconnected from its power source.
Never plug the amp into an ungrounded outlet. Tube replacement
and amp biasing can be done only by a qualified service technician.
FRONT PANEL
BACK PANEL
OLD SCHOOL 21RT
OWNERS MANUAL
PLEASE read this instruction manual carefully before switching on.
Vacuum tube amplifiers generate heat. Ensure proper ventilation.
Keep away from curtains or any flammable objects. Do not block
ventilation.
This guitar amplifier can produce high volume levels. Exposure to
high volume levels may cause hearing damage.
Protect the amp from physical knocks or bumps especially when the
tubes are hot. Let the amp cool down after use before you move it.
Never operate the amplifier without a connected speaker.
Use high quality cables only, instrument cable between guitar and
amplifier and speaker cable between amp and a speaker.
Don't take any risks, if there are any doubts, consult your dealer
and/or a qualified technician.