Fender Bassman 25 User manual

BASSMAN 25
p/n 022-4501-000 (120V)
SERVICE MANUAL
CONTENTS:
Notices
Specifications
Parts lists:
PCB assembly
Chassis assembly
Cabinet assembly
end item
Schematics/Drawings
Fender Musical Instruments Corp. 7975 North Hayden Road Scottsdale, AZ 85258

BASSMAN 25
SERVICE MANUAL
JANUARY 2000
IMPORTANT NOTICE:
The information contained herein is CONFIDENTIAL and PROPRIETARY to Fender Musical Instruments Corp. It is
disclosed solely for use by qualified technicians for purposes of equipment maintenance and service. It is not to be
disclosed to others without the expressed permission of Fender Musical Instruments Co. All specifications subject to
change without notice.
For warranty repair service, only Fender specified part numbers are to be used. It is recommended they also be used
for post-warranty maintenance and repair.
Parts marked with an asterisk (*) indicate the required use of that specific part. This is necessary for RELIABILITY and
SAFETY requirements. DO NOT USE A SUBSTITUTE!
A coded naming convention is used in the description of certain parts. The codes and what they mean are as follows:
CAPACITOR CODES HARDWARE CODES
CAP AE = Aluminum Electrolytic BLX = Black Oxide
CAP CA = Ceramic Axial CR = Chrome Plated
CAP CD = Ceramic Disk HWH = Hex Washer Head
CAP MPF = Metalized Polyester Film M = Machine Screw
CAP MY = Mylar NI = Nickel Plated
CAP PFF = Polyester Film/Foil OHP = Oval Head Phillips
PB = Particle Board
RESISTOR CODES PHP = Pan Head Phillips
PHPS = Pan Head Phillips Sems
RES CC = Carbon Comp SMA = Sheet Metal "A" Point
RES CF = Carbon Film SMB = Sheet Metal "B" Point
RES FP = Flame Proof SS = Stainless Steel
RES MF = Metal Film TF = Thread Forming
RES WW = Wire Wound ZI = Zinc Plated

BASSMAN 25
SPECIFICATIONS
Product Release No.: PR 422 (This is not a model number)
Part Number: 120V Version : 22-4501
240V Aus : 22-4531
230V UK : 22-4541
230V Eur : 22-4561
100V : 22-4571
Power Requirements: 100V Version : 100 VAC 50/60 Hz, 75W
120V : 120 VAC 60 Hz, 75W
230V : 230 VAC 50 Hz, 75W
240V : 240 VAC 50 Hz, 75W
Power Amp Section
Power Output: 25 Watts RMS into 8 Ω@ < 5% THD
Sensitivity: 2V RMS
Preamp Section
Input impedance: Input 1: 34kΩInput 2: 68kΩ
Sensitivity For
Full Power: Input 1: 250mV Input 2: 500mV
Nominal Level: Input 1: 50mV Input 2: 100mV
Tone Controls: Treble:+/-15 dB @ 8 kHz
Mid: +/-15 dB @ 1.5 Hz
Bass: +/- 15 dB @ 80 Hz
Effects Loop:Send Impedance: 1kΩ
Return Impedance: 44kΩ
Nominal Level: 0dBu
Speaker : Fender special design 8Ω, 10" (p/n 0038657000)
Dimensions: Height:16.5" (41.9 cm)
Width: 15" (38.1 cm)
Depth: 15" (38.1 cm)
Weight: 33 lbs. (15 kg)
Product specifications are subject to change without notice

BASSMAN 25
PARTS LIST
NOTE: SHADED ITEMS ARE FOR REFERENCE ONLY
PRINTED CIRCUIT BOARD ASSEMBLY
QTY PART # DESCRIPTION REFERENCE DESIGNATION
2 0048451000 BUTTON PUSH OFF WHITE @ S1, S2
1 0040987000 CABLE RIBBON 10 CKT 3.75" PW13
1 0028463003 CAP AE RDL 10uF 50V 20% C16
8 0028459003 CAP AE RDL 2.2uF 50V 20% C30-32 C35-36 C44 C68 C73
2 0033607000 CAP AE RDL 2200uF 35V 20% C39 C60
1 0028482003 CAP AE RDL 220uF 50V 20% C20
13 0028467003 CAP AE RDL 22uF 50V 20% C1-3 C6 C15 C27-28 C33-34 C42 C48-49 C63
4 0028471003 CAP AE RDL 47uF 50V 20% C11-13 C21
1 0051457003 CAP CD 100pF 500V 5% C52
4 0051405003 CAP CD 120pF 500V 5% C43 C45 C54 C56
1 0051960003 CAP CD 180pF 500V 10% C51
2 0051445003 CAP CD 22pF 500V 5% C55 C66
1 0020867003 CAP CD 330pF 1000V 10% C53
2 0051413003 CAP CD 33pF 500V 5% C14 C22
1 0051407003 CAP CD 390pF 500V 10% C76
1 0051408003 CAP CD 47pF 500V 5% C65
2 0051459003 CAP CD 560pF 500V 10% C72 C75
18 0034788003 CAP CR .1uF 50V 20% .2" LS C5 C7-8 C19 C23 C26 C29 C37-38 C40-41
C47 C50 C57-59 C69 C71
1 0027255003 CAP MPF .001uF 100V 10% C24
1 0027259003 CAP MPF .0033uF 100V 10% C61
1 0027262003 CAP MPF .0068uF 100V 10% C70
1 0027267003 CAP MPF .022uF 100V 10% C25
1 0027272003 CAP MPF .047uF 63V 10% C64
1 0052003003 CAP MPF .1uF 250V 10% C74
1 0053860000 CAP MPF .1uF 250VAC 20% C9
3 0027278003 CAP MPF .1uF 63V 10% C4 C17-18
2 0027281003 CAP MPF .22uF 63V 10% C46 C67
1 0027286003 CAP MPF .47uF 63V 10% C62
2 0038658000 CONTROL SNAPIN 50k 30C R95, R101 (volume, aux. level)
3 0038655000 CONTROL SNAPIN 50k B DETENT R98-100 (bass, mid, treble)
6 0064089001 DIODE 1N4003 LL D2-3 D12-15
8 0006260001 DIODE 1N4448 SIGNAL D1 D4-10
1 0027329001 DIODE ZEN 1N5228B 3.9V 5% LL D11
3 0026000001 FASTON TAB, .187" P4 P7 P10
10 0025802000 FSTN TAB MALE .250x.032 PCB MT P1-3 P5-6 P8-9 P11-12 P14
2 0020775000 FUSE CLIP PCB 5mm At F1
1 0027419000 HDR .1 CTR 10 CKT SQ PIN P13
10054374000 HEATSINK PLATE TDA1514UA HS1
6 0016795000 IC OP-AMP DUAL TL072 U3 U5-6 U8-10
1 0027404000 IC OTA CA3080AE U7
1 0054377000 IC POWER AMP TDA1514A 40W U1
1 0013562000 IC REGULATOR +15V MC7815CT U4
1 0013564000 IC REGULATOR -15V MC7915CT U2
1 0054378000 INSULATOR MICA 9 PIN SIP At U1

BASSMAN 25
PARTS LIST
PRINTED CIRCUIT BOARD ASSEMBLY (CONT)
QTY PART # DESCRIPTION REFERENCE DESIGNATION
3 0051658000 JACK MONO R/A J1 J7-8
1 0025933000 JACK RCA DUAL HORIZ PC MNT J6
4 0053450000 JACK STEREO R/A J2-5
1 0055595000 JACK STEREO R/A w/SL SHUNT J9
2 0049948000 LED, RED LONG LEAD LUMEX D16-17
10055619000 PCB FAB BASSMAN 25
1 0027869001 RES CF 1/2W 5% 470ohm LL R107
1 0030737001 RES CF 1/2W 5% 5.6ohm LL R18
15 0024997001 RES CF 1/4W 5% 100k LL R7-8 R17 R20 R22 R32 R41 R50 R52
R73 R75-76 R88 R92 R105
1 0024952001 RES CF 1/4W 5% 100ohm LL R57
19 0024981001 RES CF 1/4W 5% 10k LL R9 R12-16 R30 R43 R45 R53-56 R60-63 R65 R68
1 0024937001 RES CF 1/4W 5% 10ohm LL R64
1 0024998001 RES CF 1/4W 5% 120k LL R70
2 0024999001 RES CF 1/4W 5% 150k LL R69 R94
1 0024985001 RES CF 1/4W 5% 15k LL R40
12 0024965001 RES CF 1/4W 5% 1k LL R11 R19 R21 R28 R39 R49 R51 R72 R74 R79 R82 R103
4 0025069001 RES CF 1/4W 5% 1M LL R44 R71 R102 R104
4 0024971001 RES CF 1/4W 5% 2.2k LL R78 R84 R87 R90
1 0025059001 RES CF 1/4W 5% 220k LL R106
1 0024956001 RES CF 1/4W 5% 220ohm LL R83
5 0024987001 RES CF 1/4W 5% 22k LL R46-47 R58-59 R91
2 0024973001 RES CF 1/4W 5% 3.3k LL R10 R31
1 0025077001 RES CF 1/4W 5% 3.3M LL R96
1 0024975001 RES CF 1/4W 5% 3.9k LL R29
2 0028016001 RES CF 1/4W 5% 300k LL R66-67
1 0025061001 RES CF 1/4W 5% 330k LL R97
6 0024989001 RES CF 1/4W 5% 33k LL R3 R5 R23-24 R26 R48
2 0029472001 RES CF 1/4W 5% 4.3k LL R81 R86
3 0024977001 RES CF 1/4W 5% 4.7k LL R42 R85 R89
4 0028990001 RES CF 1/4W 5% 51k LL R33-36
4 0024995001 RES CF 1/4W 5% 68k LL R25 R27 R77 R80
1 0024996001 RES CF 1/4W 5% 82k LL R93
4 0031895001 RES MOX 2W 300 ohm 5% R1 R4 R37-38
1 0027628001 RES MOX 2W 5% 47ohm LL R6
1 0029670000 RES WW BT 5W 10% 150ohm R2
2 0027638000 SCRW TF 4-40x3/8 HWHS ZI @ U1
2 0032908000 SCRW TF 6-32x3/8 PHP ZI @ HS1
2 0036178000 SPACER LED .5x.1 BRN @ D16-17
1 0038828000 SWITCH 4P2T ALT/ACT PC MOUNT S2
1 0028091000 SWITCH PUSH SLFLK SHRT STRK S1
1 0041465003 XSTR N-CH JFET J113 TO-92 Q1
1 0014408003 XSTR PNP DRLGTN MPSA63 TO-92 Q2

BASSMAN 25
PARTS LIST
CHASSIS ASSEMBLY
QTY PART # DESCRIPTION REFERENCE DESIGNATION
1 0055660000 CHASSIS BASSMAN 25
1 0054642000 CONNECTOR IEC SNAP IN
1 0020786000 FUSE QA 20mmx5mm 250v .500A 230V/240V
1 0048381000 FUSE QA 20mmX5mm 250V 1A CSA 100V/120V
1 0034885000 HEATSINK BAR RD/HT/JM/CHMP110
5 0055776000 KNOB ROT W/ CH INS BASSMAN
5 0033206000 BUSHING KNOB SPACER
10055661000 PANEL FRONT BASSMAN 25
10055662000 PANEL REAR BASSMAN 25
10055620000 PCB ASSY DOM BASSMAN 25
10055657000 PCB ASSY EXP BASSMAN 25
4 0069393000 NUT 6-32 HEX EXT LOCK @ Xfmr
8 0055838000 NUT PLASTIC REAN @ Jacks
1 0051155000 SCRW SMB #4X3/8 PHP BLX @ RCA Jack Assy
1 0038900000 SCRW TF 6-32X1/4 PHP ZI @ Chassis Ground
2 0028500000 SCRW TF 8-32x3/4 HWH SLTD Z1 @ H.S. Bar
3 0051404000 STANDOFF NYLON BLK .375
1 0025935000 SWITCH DPST .187 TAB (DOM) Domestic & Export
1 0033613000 XFMR PWR 120v
1 0040611000 XFMR PWR CHMP110/BXR25 230V
CABINET ASSEMBLY
QTY PART # DESCRIPTION REFERENCE DESIGNATION
0.1 0040046000 CARPET BLACK
2 0029071000 CORNER NOTCHED NICKLE (FD)
8 0019276000 GLIDE CAB 1.24x.335 NI
8 0019275000 INSERT GLIDE CUSHION 1.27 DIA
1 0027846000 HANDLE 9.25" NO LOGO
2 0025395000 HANDLE CAP 1 HOLE NI(DWG17420)
1 0032524000 INSERT HANDLE
6 0021972000 NUT T 10-32X3/4 STR 3 PRNG BLX
2 0022244000 SCRW M 10-32x1-1/8 OHP NI
4 0026571000 SCRW SMAB 8X5/8 THP NI
6 0026625000 SCRW WOOD 8x1 FH
0.01 0040149000 TAPE ALUM 5"X60YDS
2 0053990000 TUBE CARDBD 2 1/8 ID X 1 5/8 L
1.26 0051343000 VINYL TOLEX 4227A

BASSMAN 25
PARTS LIST
END ITEM ASSEMBLY
QTY PART # DESCRIPTION REFERENCE DESIGNATION
10055359000 CABINET ASSEMBLY BASSMAN 25
10055659000 CHASSIS ASSY BASSMAN 25 100V JAP
10055655000 CHASSIS ASSY BASSMAN 25 120V
10055656000 CHASSIS ASSY BASSMAN 25 230V EUR/UK
10055658000 CHASSIS ASSY BASSMAN 25 240V AUS
1 0047248000 CORD POWER W/ IEC CONN DOM
1 0053997000 CORD PWR W/IEC CONN 100V JPN
1 0047251000 CORD PWR W/IEC CONN 230V
1 0047249000 CORD PWR W/IEC CONN 230V UK
1 0047250000 CORD PWR W/IEC CONN 250V Australia
1 0055727000 GRILLE BASSMAN 25
1 0055731000 LOGO BADGE BASSMAN AMPS
1 0050850000 NAMEPLATE VINTAGE PLASTIC SMAL
1 0038657000 SPEAKER 10" 8 OHM
2 0050311000 NUT 2-56 NYLON INSERT 2CNME-Z @Nameplate
2 0050312000 SCRW 2-56X3/8 FHP NI @Nameplate
4 0026577000 SCRW M 10-32x1 PHP BLX @Speaker
4 0036199000 SCRW M 8-32x1-3/16 OHP BLX CP @Chassis
8 0036112000 SCRW SMAB 6x1-1/4 OHP BLX w/WS @Grille
4 0029527000 WSHR FNSH 8-5/8 FLNGD BLX WX @Chassis