Fender Deluxe 112 Plus Service Manual - Theory of Operation (Cont)

DELUXE 112 PLUS

THEORY OF OPERATION (CONT)

Diodes’ CR9-CR12 make up a voltage clamp protection circuit.  Q8 and Q9 make up a current limiting

protection circuit.  If the output is shorted, the voltage at the emitters of Q10 and Q11 will increase.  This

voltage is sensed through R100 and R107 and presented to the bases of Q10 and Q11.  When Q10 and

Q11 turn on, the drive current and bias to the output transistors is removed, which shuts down the output

section of the amplifier.

The output signal feeds through the Headphone jack circuit, before driving the speaker.  With headphones

connected to the headphone jack the speakers are muted.

PARTS LIST

PRINTED CIRCUIT BOARD ASSEMBLY

QTY      PART #    DESCRIPTION                                               REFERENCE  DESIGNATION  

1

048873001

PCB ASSY DELUXE 112 PLUS

(STUFFED)

1

031910

BREAKER THERMAL 15A 155/195DEG

TS1

1

048451

BUTTON PUSH OFF WHITE

@S1

1

028577

CABLE REVERB 30”

@P1-4

2

031756

CAP AE       4700uF       50v

C47,48

1

028458

CAP AE RDL     1uF     50V         20%

C53

4

028459

CAP AE RDL   2.2uF    50v         20%

C11,33,34,36

1

028460

CAP AE RDL   4.7uF    50V         20%

C35

6

028465

CAP AE RDL   22uF    50V          20%

C6,12,25,27,39,40

4

028471

CAP AE RDL   47uF    50V          20%

C37,38,49,50

2

025787

CAP AE RDL MINI 100uF   16V   NP

C57,58

1

039255

CAP CA    10PF   100V

C10

1

038698

CAP CA    47PF   100V

C29

1

038873

CAP CA     22PF  100V

C26

1

038699

CAP CA    100PF  100V

C23

1

038701

CAP CA      470PF   50V

C14

1

038874

CA[ CA   560PF   50V

C17

2

039263

CAP CA      100PF     100V

C3,32

2

039268

CAP CA    4700PF   100V

C1,2

4

027278

CAP MPF  .1uF   63V    10%

C41,42,59,60

2

027281

CAP MPF   .22uF   63V

C5,30

5

027286

CAP MPF    .47uF    63V

C4,15,16,43,44

1

033579

CAP PFF RDL  .0015uF   100V  10%

C21

2

033580

CAP PFF RDL  .0022uF   100V  10%

C13,28

1

033581

CAP PFF RDL  .0033uF   100V  10%

C20

1

036234

CAP PFF RDL  .015uF   100V  10%

C31

1

033590

CAP PFF RDL  .022uF   100V  10%

C19

6

033591

CAP PFF RDL  .033uF   100V  10%

C7,8,9,24,45,46

5

033592

CAP PFF RDL  .047uF   100V  10%

C18,22,51,52,56

2

033596

CAP PFF RDL  .068uF   100V  10%

C54,55

1

024853

CAP PFF RDL    .1uF     250V  10%

C61

2

027947

CONTROL SNAPIN 100K 30C  TAPER

R26,35  (GAIN, TREBLE-DRIVE CH)

1

027949

CONTROL SNAPIN 250K 30C  TAPER

R38  (BASS-DRIVE CHANNEL)

1

027397

CONTROL SNAPIN  2K  15A  TAPER

R14  (MID)

2

027940

CONTROL SNAPIN  50K 15A  TAPER

R12,13  (CLEAN CH TREBLE, BASS)

1

027943

CONTROL SNAPIN  50K  30C  TAPER

R24  (CLEAN CHANNEL VOLUME)

3

027941

CONTROL SNAPIN 50K B TAPER

R33,34,56  (CONTOUR REVERB DRIVE CHANNEL VOL.)

2

064089

DIODE 1N4003

CR13,14

26

006260

DIODE 1N4448 SIGNAL

CR1-4,9,11,15-21,28-36,39-42

4

029045

DIODE 6A 400V 6A4 LEAD FORMED

CRC22,23,24,25

4

028776

DIODE BIAS BYV26D LEAD FORMED

CR5,6,7,8

2

027327

DIODE ZEN 1N5234B  6.2V  5%

CR10,12

2

028119

DIODE ZEN 1N5353B  16V  5W  5%

CR26,27

12

025802

FSTN TAB MALE .250X.032 PCB MT

CR1-5,7-11,13,14

2

026000

FSTN TAB MALE PCB MT .187X.032

CP6,12

2

025996

FUSE CLIP PCB .250&5MM FUSE

XF1

1

039982

FUSE QA 1-1/4X1/4 250V 4A

F1        (100/120V ONLY)