Top Panel
9
NOTE
◆ Be careful of the high temperature of the tubes during operation.
◆ Please replace the power tubes after switch off in 20 minutes, and follow the suggetion to unplug the
inset the tubes.
◆ Power tubes must be matched for well function.
◆ Forbidden to make the pointer of the bias meter out of the A zone when adjusting the power tube.
◆ Make sure the supply voltage is 230V before bias adjustment.
◆ Even under normal working state, the point of the bias meter could move for the voltage fluctuation.
① (845)
②Bias Adjustment (845)
Used to adjust bias of corresponding
power tube(845)
Bias Selector Switch(845)
Used to select corresponding tube for
bias adjustment.
.HUM Balance
.
.
.V1:6SL7 .A1:845
. . DE
.
③
④ ⑤
⑥V2:6SN7 ⑦V4:22 4
⑧V3:300B
86 74 52 3
1
BIAS ADJ.
845
845
845
HUM BAL.
BIAS SEL.
V3 300B
/
V2 6SN7
/
V1 6SL7
/
V4 22DE4
/
A1 845
/
How to adjust the 845 HUM:
Turn the volume knob to the minimum or mute,
adjusting the HUM BALANCE with the flat
screwdriver, until you hear the smallest HUM.
The same for adjusting the other channel.
Mount and dismount the 845 vacuum tube:
Clockwise rotation for mounting, and
counterclockwise rotation for dismounting.
Mount and dismount the 300B vacuum tube:
The thick pin is for the large hole on the tube
socket, and the thin pin is for the small hole on
the tube socket. And please insert and extract
vertically.
Diagram 三
Bias adjustment for the power tube:
Turn the Bias Selector Switch to its opposite
direction without releasing it, adjust the
corresponding Bias Adjustment Switch with
flat screwdriver, and inspect the Bias Meter
on the top panel to make sure the pointer
keeps in the center.
