Fender Bassman 1200, Service Manual

Page 1: ... 120V SERVICE MANUAL CONTENTS Notices Specifications Circuit description Parts lists PCB assembly Chassis assembly End item Footswitch assembly Footswitch PCB Schematics Service diagrams Fender Musical Instruments Corp 8860 East Chaparral Road Suite 100 Scottsdale AZ 85250 ...

Page 2: ...rked 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 ...

Page 3: ...15dB 40Hz Graphic Equalizer 12dB 31 5Hz 63Hz 125Hz 250Hz 500Hz 1kHz 2kHz 4kHz 8kHz 16kHz Mid notch 20dB 700Hz Low boost 10dB 40Hz High boost 10dB 6kHz Power Amplifier Section Power output 1200 Watts RMS into 2 Ω 0 2 THD Sensitivity 1V RMS 0dBV Power Requirements 100V AC 50 60 Hz 1800W 120V AC 60 Hz 1800W 230V AC 50 Hz 1800W Speaker Complement Designed for use with the Bassman 410 or Bassman 215 Ba...

Page 4: ... R70 equalization The Baxendall circuit output is then sent to a graphic equalizer which can be selected by the footswitch or graphic EQ button S61 on the front panel The far right graphic EQ slider R660 is a 10dB trim for graphic EQ gain compensation Next the signal is presented to a second order state variable filter before being presented to the compressor circuit Said filter is set to 420 Hz A...

Page 5: ...inrush limiting is accomplished by TH1 a negative temperature coefficient thermistor The power supply employs a toroidal power transformer with only one tapped main secondary Two large bridge rectifiers are used to obtain 47VDC and 94VDC High voltage 356VDC for vacuum tube sections is generated by half wave multiplier comprised of CR92 CR95 C125 C128 Low voltage 22VDC and 10 28VDC variable fan is ...

Page 6: ...64 66 C69 C72 74 C76 C105 C134 C137 C601 C603 613 C634 C636 C638 639 4 0028460003 CAP AE RDL 4 7UF 50V 20 C12 13 C28 C161 2 0053955003 CAP AE RDL 47UF 160V 20 C92 93 4 0054206000 CAP AE RDL 47UF 350V 20 C125 128 1 0054205000 CAP AE RDL 47UF 450V 20 C129 6 0047195003 CAP AE RDL 47UF 63V 20 C4 C86 C98 99 C803 C807 2 0037182000 CAP AE RDL 6800UF 63V 20 C121 122 2 0053915000 CAP AE100V10000uF 20 C123 ...

Page 7: ... 100K B TAPER R113 R88 R98 1 0053926000 CONTROL SNAPIN 10K 5A 10K 5C R107 1 0053929000 CONTROL SNAPIN 10K B 250K B R25 2 0039053000 CONTROL SNAPIN 1M 30A R20 R47 1 0053928000 CONTROL SNAPIN 250K 30A TAPER R37 2 0031087000 CONTROL SNAPIN 25K 2B W DETENT R67 R70 1 0027941000 CONTROL SNAPIN 50K B TAPER R116 15 0064089001 DIODE 1N4003 LL CR44 45 CR103 104 CR801 802 CR805 808 CR812 815 CR819 4 00267300...

Page 8: ...A SSM2120 U8 1 0013562000 IC REGULATOR 15V MC7815CT U21 1 0013564000 IC REGULATOR 15V MC7915CT U22 1 0051856000 IC QUAD 2 IN NAND GATE 4011 U18 1 0027387000 INDUCTOR AIR CORE RDL 2 5UH L1 4 0017974000 INSULATOR MICA TO 220 20 0038815000 INSULATOR SILICONE TO 3P 1 0051006000 JACK 1 4 PCB DUAL TIP MONO J1 2 0051658000 JACK MONO R A J2 J12 4 0029175000 JACK PHONE 1 4 HI CURRENT PC J8 11 4 0053450000 ...

Page 9: ...R256 R271 4 0024985001 RES CF 1 4W 5 15K R642 R647 R651 R656 2 0024986001 RES CF 1 4W 5 18K R633 R638 11 0024965001 RES CF 1 4W 5 1K R17 R93 R103 R151 R153 R646 R655 R803 804 R811 R817 18 0025069001 RES CF 1 4W 5 1M R9 R15 R27 R30 R39 R59 R64 R94 R104 R139 R240 R246 R270 R274 R302 303 R670 R673 6 0024971001 RES CF 1 4W 5 2 2K R235 R248 R257 R652 R810 R816 1 0025075001 RES CF 1 4W 5 2 2M R289 5 002...

Page 10: ...LL R258 259 4 0024994001 RES CF 1 4W 5 56K R75 R78 R641 R650 1 0028948001 RES CF 1 4W 5 6 2K R63 3 0024979001 RES CF 1 4W 5 6 8K R237 R666 667 1 0029596001 RES CF 1 4W 5 62 OHM R185 7 0024995001 RES CF 1 4W 5 68K R92 R102 R138 R181 R234 R629 R632 2 0025942001 RES CF 1 4W 5 7 5K R645 R654 1 0028153001 RES CF 1 4W 5 75K R283 2 0029581001 RES CF 1 4W 5 8 2 OHM R170 171 1 0024980001 RES CF 1 4W 5 8 2K...

Page 11: ...56 57 PLUS 8 HEATSINK 2 0028500000 SCRW TF 8 32x3 4 HWH SLTD Z1 1 0051411000 SPACER LED 4X 1 TURQUOISE LD61 4 0036178000 SPACER LED 5x 1 BRN LD3 5 LD6 1 0050817000 SWITCH PB PC VERT MNT DPDT S61 8 0028091000 SWITCH PUSH SLFLK SHORT STROKE S1 8 1 0053923003 THERMAL SENSOR PTC 80 DEG C RT2 1 0052051000 THERMISTOR NTC 20 TH1 1 0051418003 THERMISTOR PTC100 DEG C RT1 2 0029167000 TUBE SOCKET 9 PIN PCB ...

Page 12: ... UK 1 048912 CABLE ASSY PWR 14GA 120V 250 120V 1 026622 CABLE ASSY PWR 14GA 230V 250 230V 1 038602 CABLE ASSY PWR AUST 250 TAB 240V AUST 1 057488 CHASSIS TOP BASSMAN 1200 1 057487 CHASSIS BASSMAN 1200 1 053911 COOLING FAN DC 24V 2 049650 CORD WRAP STYLE 2 1 020802 FUSE QA 20mmx5mm 250v 10A 230V 240V VERSIONS 1 032030 FUSE TD 1 1 4x1 4 250v 20A 120V 100V VERSIONS 11 053986 KNOB ROTARY SS W CHR INSE...

Page 13: ...WICH 4 053952 STANDOFF NYLON BLACK 250 040582 SWITCH DPST 250 TAB GLOBAL EXPORT 1 039236 SWITCH ROCKER DPST PSEUDO IEC DOMESTIC 2 013341 TUBE 7025 12AX7WA RUSSIAN MADE 12AX7A 1 9904300900 WASHER FLAT 1 4X1 STL BLX FOR XFORMER 4 027520 WSHR FLAT 380x 630 FIBER AT SPEAKER JACKS 5 031153 WSHR FLAT 3 8x 614 NI AT 1 4 JACKS 1 016436 WSHR LCK INTL 3 8x 687x 035 NI AT 1 4 INPUT JACK 4 026401 WSHR SHLDR F...

Page 14: ...UP LEFT FTSW 1 028143 HSG END CUP RIGHT FTSW 1 028141 HSG FTSW 3 BUTTON 1 031647 NUT HEX 12mmx1mm Nl 8 028684 SCRW SMB 6x3 8 PH PHS BLX 3 031899 WSHR NYL 485x 775x 150 TK FOOTSWITCH PCB ASSEMBLY QTY PART DESCRIPTION REFERENCE DESIGNATION 1 053898 PCB FAB FTSW 3 BTN SUNN BASS 2 000626 DIODE 1N4448 SIGNAL LL 1 031017 DIODE ZEN 1N5223B 2 7V 5 2 027327 DIODE ZEN 1N5234B 6 2V 3 028039 LED RED 5x5MM SLB...

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