•
50W & 100W model:
EL34: 30mV to 40mV
6L6: 36mV to 46mV
•
200W model:
KT88: 25mV to 35mV
8. If adjustment is necessary, turn the bias control with the small flathead screwdriver
while monitoring the number on the multimeter to obtain the desiered setting.
Changing Output Tube Bias:
1. If ON, turn the amplifier OFF and wait for tubes to fully cool. To remove, gently grab
the plastic or metal base and pull upwards, using a very slight circular motion if
necessary.
2. Insert the new tubes, minding the “key” on the bottom of each tube so that it matches
with the socket.
3. Turn the bias control to minimum (All the way counter-clockwise).
4. Follow steps 2-7 from the “Measuring & Adjusting Output Tube Bias” instructions
above.
1. Turn the bias control clock-wise with a small screwdriver until you reach the desired
bias setting listed above and also on the Tube Chart & Bias Diagram on pg. 12
2. Allow tubes to idle for 15 minutes, then recheck bias and adjust if necessary.
Safety
•
Always use a 3-prong cable into a grounded outlet. This makes sure the amplifier is
always grounded and safe during the rare occurrence the chassis should become "live"
(electrified).
•
Tubes become very hot during normal operation. Allow them to cool before handling
to prevent burns.
•
Never change tubes with the amplifier ON.
•
Always make sure the amp's vents are open, allowing heat to escape and air to flow
freely.
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