Date:

April 20, 1995Sheet

1

of

1

SizeDocument Number

REV

B--- --- ---

1.0

Title

PREAMPLIFIER TYPE AO-28

MODEL B3, C3, RT3

GC23

.033

EF

TO

"VOLUME"

TABLET

C24

82PF

C22

24-90PF

C17

680PF

RADIO-PHONO

EXPRESSION

CONTROL

C16

.033

C6

30PF

C15

51PF

C2

39PF

R9

820K

R4

1.8M

R5

10M

A

C3

100PF

R6

47K

R3

270K

NON-VIB

CHANNEL

INPUT

5

1

62

7

V1

6AU6A

R8

470K

C5

.01

R10

3.9M

130V

R27

1.8M

R29

330K

+1.7 (V2)

2

1

3

V4A

12AX7A

145V

+280

C18

220PF

C20

220PF

R30

1.8M

R32

1.8M

R31

68K

R33

68K

60PF/SEC

R35

3.3M

+1.7V (V2)

7

6

8

V4B

12AX7A

R34

15M

140V

+280

R37

270K R39

330K

R38

390K

R36

330K

7

6

8

V3B

12BH7A

C26

30/25

R42

1200

+290

R41

100K

12V

R40

.3M

TONE

GBN

T3

CABINET

TO TONE

+205

335V

C25

.001

R97

4500

TO HTRS

T7

"BL"

C19

.0022

C21

.001

C35

150PF

DINPUT FROM

VIBRATO SCANNER

COUTPUT TO

VIBRATO LINE

C13

1.0

R7

2.2M

+280

+1.7 (V2)

C7

24PF

C11

.0047

C4

.33

INPUT FROM

MATCHING XFMRS

THRU VIBRATO

TABLETS

R13

4.7M

B

C8

100PF

VIBRATO

CHANNEL

INPUT

R14

10M

R16

47K

R12

270K

R18

10M

C12

.0047

5

1

62

7

V2 6AU6A

R15

2.7M

+290

2

1

3

V3A

12BH7A

R25

100

R63

390K

C33

.0033

C34

.001

C33

.0022

R63

390K

R62

220K

C34

.001

R62

100K

C32

390PF

C35

390PF

"GY"

117VAC

60 HZ

375V

R91

900

C56

40/450

734 1

6

V8

6X4

+280

+290

C60

50/300

R95

4.7K

R96

4.7K

R94

4.7K

+37

+33

R99

180

R98

7500

R100

2.7K

R101

2.7K

T5

C57

40/400

C58

30/350

C56

10/350

TOP VIEW

THESE COMPONENTS GO BETWEEN

POINTS "P" AND "D" IN AO-28-1

LETTER ONLY) INSTEAD OF

AMPLIFIERS (WITH NO CODE

THOSE SHOWN AT LEFT

R24

22K

R22

820

95V

C10

.33

R20

2.2M

R19

470K

R17

1.2K

+280

R23

22K

R21

1M

C9

30/25

+1.7V

R48

470K

R47

47K

6

7

1

V5 6C4

T5

C28

.047

R53

47K

R52

47K

*

**

(* SEE NOTE)

C32 .0082

T6

R61

39K

P

2

1

3

V7A

12AU7A

CHANNEL BALANCE

SELECT FOR

(MOUNTED ON "P" TERMINAL)

V8

C56

C57

C58

T1

V1

V4

V3

EXPRES-

SION

CONTROL

T3

C9,C26

C59,C60

V5

V6

V2

V7

T4

T6

NK

MJ

HE

CP

DA

BL

GYBLBN

GG

F

N

+33

R60

30K

PERCUSSION

CUTOFF

+205

R58

4.7M

7

6

8

V7B

12AU7A

6

7

1

V6

6C4

C31

.33 R54

47K

+37

*

+205

C29

100PF

C30

25/25

R49

2.2K

H

PERCUSSION

CHANNEL

INPUT

T4

TO

PERCUSSION

SWITCH

R50

22

R51

4.7K

K

J

R55

82K

25V

+33

R56

22K

R57

1.5M

L M

TOPERCUSSSION

SWITCH

NOTE:

R52,R53,R54,C32 IN

AO-28-1 AMPLIFIERS

(WITH NO CODE LETTER ONLY)

SIDE VIEW

Date: December 11, 1995 Sheet 1 of 1

Size Document Number REV

E --- ---- --- 1.0

Title

B3/C3 SCHEMATIC

F

C22

24-90PF

R37270K

C17680PF C24

82PF

C23.033

VOLUMESOFT

NORMAL

E

C16.033

RADIO-PHONO

R29

330K

EXPRESSIONCONTROL

+280V

C2

39PF

1

6 2

7

5

V16AU6

C5.01

R9

820KTO BALANCE CHANNELS

R103.9M

C8

30PFC15

51PF

R10 - SELECT AT TEST

145V

130V

R8470K

OFF

ON

OFF

ON

VIBRATOGREAT

VIBRATOSWELL

R2

1MC1470PF

R4

1.8M

R5

10M

R6

47K

C3

100PF

A

T2MATCHINGTRANSFORMERUPPER

PEDALDRAWBARS

TYPICAL GROUP OF UPPER(SWELL) MANUAL DRAWBARS

TYPICAL GROUP OF LOWER(GREAT) MANUAL DRAWBARS

T1MATCHINGTRANSFORMER(LOWER AND PEDAL)

2 36

5

B

R13.9M

R3270K

(FROM V2)

R13

4.7M

C7

24PF

R7

2.2M

C4.33

R28

270K

R271.8M

+1.7V(FROM V2)

2

1

3

V4A12AX7

C11

.0047

60V

+280V

+1.7V

C18220PF

C20220PF

R30

1.8M

R32

1.8M

R31

68K

R33

68K

R34

15M

60PF/SEC

R353.3M

7

6

8

V4B

12AX7A

R39

330K

R38

390KR36

330K

140V

+1.7V(FROM V2)

+280V

G

G

BN

C25.001

T3

C2630/25R42

1200

R41

100K

12V

7

6

8

V3B

12BH7A

+290V

R40

300K

TONE285V

C19.0022

C21.001

D

7

6

8

V3B12BH7

R19470K

C12

.0047

R211M

R22820

R25

100

C13

1.0C

+290V

130V

100V

95VPERCUSSIONSIGNAL

R14

10M

R15

2.7M

R12270K

R16

470KC8

.0001

R171.2K

1

6 2

7

5

V26AU6

60V

R202.2M

UPPER MANUALPRESET PANEL

LOWER MANUALPRESET PANEL

012345678

UPPER MANUAL

LOWER MANUAL BUSBARS

91

(GEN 49-91)

BUSBARS

2 36

5

C10.33

+1.7V(TO V1,V4)

C930/25

R62

100K

R2322K

R2422K

C32

390PF

C34

.001R63390K

C35150PF

+280V

R44

22K

VIBRATOSWITCH

CLOSEDIN V1/C1

CLOSEDIN V1,V2,V3

CLOSEDIN V2/C2

CLOSEDIN V3/C3

SCANNER

181716151413121110987654321

C33.0033

7

R6133K

+205

+205

2

1

3

V7A

12AU7

C31

.33

T5

T6+37V

200V

7

6

8

V7B

12AU7

6

7

1

V5

6C4

T4

C29

100PF

C30

25/25

C28

.047

R49

2.2K

R48

470K

R47

47K

85V

H

THIRD

SECOND

OFF

ON

PERCUSSION1

44

(GEN 44-48)

4

1

(GEN 1-43)

GENERATOROUTPUTTERMINALS

R50

22

R51

4.7K

SOFT

PERCUSSIONVOLUME

J

K25V

R58

4.7M

R57

1.5M

FAST

PERC.DECAY

PERCUSSIONCUTOFF

200V

L

M

6

7 1

V66C4

SLOWR55 82K

R56 22K+33V

L1 L2

R6527K

C37

.004

C38

.004

R66

68K

R67

56K

R68

150K

R6030K

R59120K

+33V

L3 L5 L6L4

C39

.004

C40

.004

C41

.004

R70

150K

R72

180K

R74

180K

R76

180K

R69

39K

R71

33K

R73

18K

R75

12K

L13L12L11L10L9L8L7

C42

.004

C43

.004

C44

.004

C45

.004

C46

.004

C47

.004

C48

.004

L18L17L16L15L14

R7715K

C49

.004

C50

.004

C51

.004

C52

.004

C53

.004

C54

.001

T5

T4

T6

TOP VIEW

VIBRATO DELAY LINE

EXPRES-SION

T3C56C57C58

T1

C9,C26

C59,C60

1

2

NINE CONTACTS AND CONNECTIONS

SAME AS "B" EXCEPT THATUNDER "A#" ADJUST KEY ARE

THESE THREE DRAWBAR WIRES

NINE CONTACTS UNDER TYPICALPLAYING KEY.

GO DIRECTLY TO KEY CONTACTS.

3

NOTES:

C6050/300

R97

4500R98

7500

+37V

+205V

+290V

335V

R94

4.7K

6.0VHEATERS

T7

NORMAL

OFF

ON BL

R4612K

STARTSWITCH

RUNSWITCH

R85 5

R84 5

R8010

R82 47

R81 10

8 CONTACTS UNDERTYPICAL PEDAL KEY

TONEGENERATOR

L20 R83 470

PEDAL SWITCH

BUSBARS

TERMINALSTO GENERATOR

(SEE PEDALWIRING CHART)

(1000)HEATER(IF USED)

R88600

R86 20R87

250

STARTINGMOTOR

SYNCHRONOUSMOTOR

GY

117VAC50/60HZ

TO GND340VRMS PINS 1,6

375VR91

900

C57

40/400

C56

40/450

73

4 1

6

V8

6X4

R95

4.7K

C58

30/350

C56

10/350

R1002.7K

R101

2.7K

R96

4.7K

R99

180

+33V

+280V

NINE CONTACTS AND CONNECTIONSUNDER "B" ADJUST KEY.

4

5 NINE CONTACTS AND CONNECTIONSUNDER TYPICAL PRESET KEY.

PRESET PERCUSSION SWITCHUNDER "B" ADJUST KEY ONLY.

6 TO GENERATOR TERMINALS(SEE MANUAL WIRING CHART)

7 R61 SELECTED AT TESTTO BALANCE THE CHANNELS.

V8V3

CONTROL

V5V6V2V1V4 V7

Date: December 12, 1995 Sheet 1 of 1

Size Document Number REV

E B

Title

WIRING DIAGRAM - HAMMOND B3 OR C3

GYVIBLGNYLORRD

GYVIBLGNYLORRDBNBK

WH

GY

VI

BL

GN

YL

OR

RD

BN

WH

GY

VI

BL

GN

RESISTOR PANELAND PEDAL FILTERON BACK OFMANUAL ASSEMBLY

YL

OR

RD

BN

RD

BN

WH

GY

VI

BL

GN

R83

RESISTOR PANEL

YL

OR

RD

BN

WH

GY

VI

BL

GY

YL

OR

RD

BN

BNBK

A G# F# E D# C#DFGGY

VI

BL

GN

YL

OR

RD

BN

A G# F# EFGGY

VI

BL

GN

YL

OR

RD

BN

D# C#D

BK

1

BK

BK

BK

R85 R84 R81

OR

RD

R82

R86

BKYL

WH

GN

YL

R80

L20

BN

BNBL

PEDAL FILTER

RUN SWITCH

OFF

ON

ON

OFF

START SWITCH

BKBKBNYL

R87

BN

YL

RD RD

(BL)BK

91

LOWER MANUAL

LINEPANEL

13

GY

BN

GN

BL

BK

WH

WH YL

RD

VI

MATCHING XFMRT1 (LOWER MANUAL)

OR

GY

GN

BL

BNRD

YL

WH WH

VI

T2 (UPPER MANUAL)

BK

BK

OR

R1

R2

C1

BKBK

GN

BK

YL

PRESETSWITCH

UPPER MANUAL

BL

STARTINGMOTOR

SYNCMOTORGY

VIBRATO SCANNER 85

42

30

78

66

18

6 54

90

35

68

BL

YL

OR

RD

BN

RD

TONE GENERATOR

83

23

59

40

76

16

52

33

69

9 45

26

62

271

11

47

28

64

4 88

81

21

57

38

74

14

86

50

31

67

7 91

84

24

60

41

77

17

53

34

70

10

43

79

19

55

36

72

12

48

29

65

5 89

82

22

58

FREQUENCY NUMBERS IN CONSECUTIVE ORDER

46

27

63

3 87

39

75

15

51

32

80

68

20

8 56

44

37

25

73

61

13

1 49

1

YL

YL

GN

RD

BN

R46R59

WH YL GN

BK

GNGNYLWH

BL

COLOR CODE

BK BLACKBNRDORYLGN

BROWNREDORANGEYELLOWGREEN

PERCUSSION SWITCH(REAR VIEW, COVER REMOVED)

GN

YL GN

YLYL23456782345

5678910

11

57911

SCANNER TERMINAL NUMBERS

6782345678

R44

13

14

15

6912

15

16

17

18

VIBRATO SWITCHTERMINALS ONDRAWBAR BASE

PEDAL SWITCH

AC LINEJACK TO

TONE CABINET

OUTLET BOXGY BK

BL

BN

RD

GY BL BN

GY

BL

BN

G G F E C

BK

GN

BN

GNBKGN

P D A B

RD

YL

YL

BN

BL

1

BL

BN

GN

L N K M J H

YL

YL

RD

RD

PREAMP

VIBRATO LINE TERMINAL NUMBERS

151413121110987652 3 4

VIBRATO LINE BOX

CONTROL PANEL(REAR VIEW, COVER REMOVED)

181716

GN BLVIGYWHB

BLUEVIOLETGREYWHITEBARE