After the amplifier has warmed up thirty minutes, the procedure just de-
scribed should be repeated. NOTE: It is normal for these LEDs to flash
or flicker when the amplifier is in use.
This biasing procedure should be performed whenever the amplifier’s
output tubes are replaced and after each six months of average use.
PLATE FUSE:
Your Premier 140 has been fitted with plate supply fuses
which are designed to protect the amplifier circuitry in the event of out-
put tube failure. The fuse holders are physically located near the
speaker connectors. The cap unscrews counter clockwise to remove
the fuse (a KTK-1). An LED near the fuse holder will light when the fuse
is blown.
What happens when the fuse blows? If one of these fuses should blow,
it usually indicates a marginal output tube (one of four for each channel -
odd numbered tubes for the right channel, even numbered tubes for the
left channel) and an attempt should be made to identify and replace it,
by either (a) replacing the fuse and turning on the amp while watching
the output tubes carefully; look for a bright white or blue flash inside the
tube. If nothing happens, then (b) lightly tap the output tubes one by one
with the plastic handle of a screwdriver while watching for flashes inside
the tube. If efforts to identify the bad tube fail, the best course of action is
to replace both tubes in the channel that blew the fuse. If the tubes are
over two years old, or have more than 1,500 hours on them, a complete
replacement tube set is probably in order.
The sonic effects of a blown fuse are very low, very distorted sounds
from the speaker being driven by that channel.
TO AVOID SHOCK, ALWAYS TURN OFF THE AMPLIFIER BEFORE
REMOVING THE FUSE HOLDER CAP.
Replacement fuses are available from conrad-johnson dealers.
Premier 140 Owner's Manual
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Содержание Premier 140
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