Carot One Ernestolone, Руководство пользователя

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5.1 DC Bias Voltage Tuning
Since each tube might derivate a bit in parameters, especially from different
series, it needs to re-tune the DC bias voltages to guarantee the machine is
working in the best point and performing the best sound quality.
There are two blue precise adjustable potentiometers (P1, P2) for tuning the
DC bias voltage of each channel. The DC bias has been tuned in factory. But
after run-in for a period or changed another tube, it would be deviated that the
fine-tuning is needed.
Before you tune these, you need a screwdriver (take off the case), a small
screwdriver. (Turn the screw of the potentiometer) and a (digital) multi-meter
to detect the DC bias voltage:
1. Use screwdriver to take out the two upper level screws in the front panel &
another two screws in the back panel. Then, open the upper case.
2. Power ON the machine with no audio signal input.
3. Wait at least 5 minutes for the machine to run in.
4. Use the multi-meter to detect the DC voltage between the test point A (L)
[red] in the PCB & the GND [black] (e.g. the ring of the power switch or the
outer ring of those RCA sockets) of the LEFT channel.
5. Turn the screw on the top of the P1 potentiometer by a small screwdriver
clockwise or anticlockwise until the voltage as close as to +6~+8V.
6. Then, repeat step 4 and 5 for the RIGHT channel by changing the test point
to A (R) [red] and turning the screw on the top of the P2 potentiometer.
7. Power OFF the amplifier.
8. Cover back the upper case and tighten the screws.