FRANÇAIS
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IT
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9
Top view
BIAS ADJ.: Bias adjustment screws for tubes V3 and V4.
BIAS ADJ.: Bias adjustment screws for tubes V1 and V2.
BIAS ADJ.: Bias adjustment screws for tube V5.
1
2
3
In order to make the machine work condition of the best, it is
recommended to use about 150 hours, according to the above
method to test the working state of power tube.
Adjustment method: noise when the machine appear hum noise,
adjust the V1, V2, V3, V4 potentiometer noise, and listening to the
corresponding channel speaker to minimize noise.
If you have any questions, please contact a local maintenance
service or your local dealer.
Bias adjustment for 845 tubes.
Notes: You do not need to perform the bias adjustment when using the amplifier for the first time.
Turn on the amplifier and wait for about ten minutes.
WARNING :
When making adjustments, be careful not to burn yourself with tubes that are very hot.
V1, V2, V3, and V4 tubes are auto-biased and you do not need to adjust the bias. You can read the bias level from
the bias meter and see whether they are at the same level or not. If they are not at the same level it means there is
something wrong with the working current of the tube. Input, Driver and Power tubes must be matched for the best
results.
Inspect the ampere meter on the front panel and make sure the needle is in the area shown on this diagram (below)
ia=70mA.
V1 to V4: Power
845 tubes
V5: Driver
300B tube
V6: Preamp stage
12AX7 tube
V7: Driver
310A tube
V1
V5
V7
V6
HUM BALANCER
V1
V2
V3
V4
V2
V3
V4
HUM BALANCER
HUM BALANCER
2010.10.12
2
1
3
V1
V5
V7
V6
HUM BALANCER
V1
V2
V3
V4
V2
V3
V4
HUM BALANCER
HUM BALANCER
2010.10.12
