Mod 101 - Page 54

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T14
V4
V3
TR
1
TR
1
TR1
R(BIAS)
1650P
374BX
COLD
HOT
DANGER
HIGH VOLTAGE
MAY BE PRESENT
ON FILTER
CAPACITORS
DO NOT TOUCH!
22µF 500V
80µF 450V
80µF 450V
22µF 500V
22µF 500V
22µF 500V
COM V
mV
37.5
Start with pot turned
all the way to cold.
ON
OFF
POWER STANDBY
PLUGGED
IN
Connect
to
Speaker
Cabinet
BASS TREBLE VOLUME
0 10
5
2 8
3
4 6
7
1 9
0 10
5
2 8
3
4 6
7
1 9
0 10
5
2
8
3
4 6
7
1 9
Set for
mV(DC)
V
R
=
I
OHM’S LAW
V =
VR
=
I
OHM’S LAW
x
mV
56.1
Set for
mV(DC)
V =
COLD
6L6GC
BIAS
POINT
37.5 mV
1.6 Ω
=
23.4 mA
56.1 mV
1.6 Ω
=
35.06 mA
6L6GC bias range: 10 mA – 50 mA
(35 mA is used commonly)
(35 mA) (1.6 Ω)
x =
56 mV
Apply Ohm’s Law to find the corresponding mV
reading for your resistor value:
I = 35 mA
R = 1.6 Ω
V = ?
Higher Value: easily overdriven
Lower Value: cleaner
6L6GC’s
12AX7/
ECC83
12AT7/
ECC81
Drawing 24