Dynaco SCA 80 Q Schematic

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TAPE OUT
0 i 1

SPARE . I" _I ' "I G H
O F 4
I : i i CO REAR
TAPE AMP 12 I I I R26 MMON
o II I. 2 I C19 R27 i H
I
10 I - I
. TUNER , FRONT I i PC 7 . i T m
9 SIDE I I comiONN
PHONO 8 ' f '
II :01 9 1 ° ° Hm
SPECIAL I CIB I _-
- II ' + 49 ' - - '
| I REAR
SELECTOR SWITCH IS SHOWN I R25 b I OWL.
IN THE COUNTERCLOCKWISE i I I MAIN
I OUTPUT
C13 POSITION. REAR WAFER I I . 6 II -L- -O
I SHOWN(LEFT). I R23 I RI 5' R9 R20 I
2 I I
__ R29 R30 I' I R2 ( C8
- '° N: 3 i I | Q I"
.II ° ifi " ' 6 ' k
I. 8 we I I
6 . =- C2 R4 R14
I I l
I R33 ' 4"
R45 S.S. VIEWED FROM KNOB END I R34 [- --------------------------------------- -'
- ? . C26 ________________ __
I r
I
I 1-..- £27- VIO U T I PC'I9
I I'- L .
r - I @ GREE 9
N
FILTER I I 05
MO N I T O R l I BLACK-WHITE
TO R46(RIGHT) 0 I '-
C15 I C] 5 I Q VIOLET-WHITE
I: r; OI I I H- 3 W3 38 °
N .
O-DTO R45(RIGHT) I '- tBLACK 8
I
l R37 I
I
p I R35 C23 + l_ _________________ _J ___
_ _ _ _: I . -
I + R38 "' \C/BIFCIDEIIEENT
MODE I C25 I
I - I " BLACK-WHITE
o o I
.l I. 13 - V'OIETWH'TE VOLTAGE TEST POINTS
' BASS > YELLOW
. . l I ' C29 3 - Measured with VTVM (TVM) at rated AC line voltage, 8 ohm load,
' C33 I BLACK . .
I : ' I4 II shorted input. All voltages are DC unless speCIfled AC. Voltages not
H ' ' I I shown are not significant for servicing purposes, as they may vary widely
' =- ' C30 .
: . I : with different transistors and still be normal. Transistor lead voltages
VOLUME T _ ' . Is VIOLET shown may vary :20% or more. Other points should be within :10%.
BALANCE l I GREEN
I I m I R39 PC-18 PC-19 Q7 Q8 Q9 Q10
| l TREBLE I C31 A BLACK-WHITE I #1 O #1 71
I I E .1 .8 .3 1.2
I I ' VIOLET-WHITE #2 O #2 74
LOUDNESS I I I7 I > I #3 <0.5 #3 36 B .7 1.5 .94 1.8
I R40 0 YELLOW 4 74 4 36
I I v. I # #
O O l I I | C 32 N BLACK #5 36.5 #5 37.5 C 1 .5 10 1.8 9.4
C I I C [___]- n #6 37.5 1.4 to #6 37.5
' ' C33 . I :- :3 32 L62: 3:; O Capacitor (3-1]
I_ _______________ I _____ _ _ _ _ _J >I<
o o l #9 0 #9 i 54 AC A 71
"_- VIOLET #10 71
R24 R24 9 IO GREEN #11 0 *Measured be- I 24
EYELETS ON ALL WIRING NOT SHOWN FOR THE RIGHT CHANNEL IS BIAcK-anE #12 0 tween eyelets 17-5
? PC'7(R'GHT) THE SAME AS THE LEFT CHANNEL,. WHICH IS SHOWN. I
RESISTOR AND CAPACITOR NUMBERS ARE THE SAME FOR > 015:3ng I
THE PARTS ON BOTH CHANNELS. g DMnaCO SCA-BOQ
"- BLACK I

SCHEMATIC DIAGRAM