BOSE COMPANION 3 Schematic

Page 1

Companion® 3 Multimedia

Speaker System

Product Description

The Companion 3 multimedia speaker system is a stereo system designed to be used as a computer sound system. It can be used with any analog audio source. It has a bass module with a 6.5 inch dual voice coil woofer in a slot ported design. The two satellite speakers connect to the bass module and are easily mounted to a monitor with brackets, or can be placed on a desk or other desired surface. A wired remote control pod is used to control volume and mute/un-mute functions. It also has a second input and a stereo headphone output.

Manufacturing Information - Early Version / Later Version

There are two different versions of the Companion 3 - Early Version / Later Version. From the outside there is basically no difference but the boards inside are different. Please note the differences are documented in the Electronic Part list. If a part numbers has changed from the early version or a part number has been added to the later version a number 4 will be shown in Notes column. The product codes can be used to determined the version. The product code for the early version is 033935 and the product code for the later version is 033061. These product codes are the first six digits of the serial number and are located on the bottom of the system. The serial number should be used to determined where the system was manufactured before attempting a repair.

Reference Number 271885-SM Rev. 11

Service Manual

Electronic copy only

Page 2

Contents

Safety Information .............................................................................................................................3

Electrostatic Discharge Sensitive (ESDS) Device Handling ....................................................... 3

Specifications....................................................................................................................................4

Part List Notes ..................................................................................................................................5

Figure 1. Bass Module Assembly Exploded View ................................................................................6

Bass Module Assembly Parts List ...................................................................................................6

Figure 2. Amplifier Module Assembly Exploded View ...........................................................................7

Amplifier Module Assembly Parts list..............................................................................................7

Figure 3. Packing Exploded Veiw ........................................................................................................ 8

Packing Parts List .............................................................................................................................8

Electrical Parts List .................................................................................................................... 9-19

Main PCB Assembly Parts List................................................................................................... 9-17

Power Supply PCB Assembly Parts List ................................................................................. 17-19

Disassembly Procedures ......................................................................................................... 20-22

Test Procedures ....................................................................................................................... 23-25

Theory of Operation ................................................................................................................. 26-28

Revision History .............................................................................................................................29

Theory of Operation ................................................................................................................. 26-28

Warranty

The Bose® Companion® 3 MultiMedia Speaker System is covered by a 1-year, transferable limited warranty.

Proprietary Information

THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OF BOSE CORPORATION WHICH IS BEING FURNISHED ONLY FOR THE PURPOSE OF SERVICING THE IDENTIFIED BOSE PRODUCT BY AN AUTHORIZED BOSE SERVICE CENTER OR OWNER OF THE BOSE PRODUCT, AND SHALL NOT BE REPRODUCED OR USED FOR ANY OTHER PURPOSE.

Caution: The Companion 3 MultiMedia Speaker System contains no user serviceable parts. To prevent warranty infractions, refer servicing to warranty service centers or factory service.

Page 3

Safety Information

1. Parts that have special safety characteristics are identified by the symbol on the schematics

or by special notes on the parts list. Use only replacement parts that have critical characteristics recommended by the manufacturer.

2. Make leakage current or resistance measurements to determine that exposed parts are acceptably insulated from the supply circuit before returning the unit to the customer. Use the following checks to perform these measurements:

A. Leakage Current Hot Check- With the unit completely reassembled, plug the AC line cord directly into a 120V AC outlet. (Do not use an isolation transformer during this test). Use a leakage current tester or a metering system that complies with the American National Standards Institute (ANSI) C101.1 “Leakage Current for Appliances” and the Underwriters Laboratories (UL) 6500/IEC 60056 paragraph 9.1.1. With the unit AC switch first in the ON position and then in the OFF position, measure from a known earth ground (metal waterpipe, conduit, etc.) to all exposed metal parts of the unit (antennas, handle bracket, metal cabinet, screwheads, metallic overlays, control shafts, etc.) especially any exposed metal parts that offer an electrical return path to the chassis. Any current measured must not exceed 0.5 milliamp. Reverse the unit power cord plug in the AC outlet and repeat the test. ANY MEASUREMENTS NOT WITHIN THE LIMITS SPECIFIED HEREIN INDICATE A POTENTIAL SHOCK HAZARD THAT MUST BE ELIMINATED BEFORE RETURNING THE UNIT TO THE CUSTOMER.

B. Insulation Resistance Test Cold Check- (1) Unplug the power supply and connect a jumper wire between the two prongs of the plug. (2) Turn on the power switch of the unit. (3) Measure the resistance with an ohmmeter between the jumpered AC plug and each exposed metallic cabinet part on the unit. When testing 3 wire products, the resistance measured to the product enclosure should be between 2 and infinite MOhms. Also, the resistance measured to exposed input/output connectors should be between 4 and infinite MOhms. When testing 2 wire products, the resistance measured to exposed input/output connectors should be between 4 and infinite MOhms. If it is not within the limits specified, there is the possibility of a shock hazard, and the unit must be repaired and rechecked before it is returned to the customer.

Electrostatic Discharge Sensitive (ESDS)

Device Handling

This unit contains ESDS devices. We recommend the following precautions when repairing, replacing or transporting ESDS devices:

•Perform work at an electrically grounded work station.

•Wear wrist straps that connect to the station or heel straps that connect to conductive floor mats.

•Avoid touching the leads or contacts of ESDS devices or PC boards even if properly grounded.

Handle boards by the edges only.

•Transport or store ESDS devices in ESD protective bags, bins, or totes. Do not insert unprotected

devices into materials such as plastic, polystyrene foam, clear plastic bags, bubble wrap or plastic trays.

Page 4

Specifications

Mechanical

Dimensions: Bass Module: 8 5/8 “H x 7 1/8” W x 14” D

(21.8 x 18 x 35.56 cm)

Satellite Speaker: 3 1/2” H x 2 1/2” W x 2 3/8” D

(8.89 x 6.35 x 6.10 cm)

Control Pod: 2 1/2 “D x 1 1/8” H

(6.35 x 2.79 cm) Weight: Bass Module: 15.4 lbs (6.98 kg) unpacked Satellite Speaker: 0.5 lbs (0.23 kg) each Packaged System 19.95 lbs (9.06 kg) packed

Finish: Bass Module: Scratch-resistant, satin-finish

vinyl Satellites: Painted polymer finish

Bass Box: Slot ported

Bass Box Port Tuning: 45 Hz

Electrical

Power Rating: USA/Canada: 115 VAC 50/60 Hz Japan 100 VAC 50/60 Hz Euro 230 VAC 50/60 Hz

Nominal System Bandwidth:

Maximum SPL: 100 dB (A weighted) pink

Output: Bass: 60 Watts Satellites: 18 Watts per channel

40 Hz to 15 kHz

noise signal

Page 5

Part List Notes

1. This part is not normally available from Customer Service. Approval from the Field Service Manager

is required before ordering.

2. The individual parts on the PCBs are listed in the Electrical Part list.

3. This part is critical for safety purposes. Failure to use a substitute replacement with the same

safety characteristics as the recommended replacement part might create shock, fire and/or other hazards.

4. The part number listed was included in the latest version of the Companion 3. The Main board and the Power board for the latest version can be identified by the part number stamped on the component side of the board. Power Board - 285350-001 Main Board - 280066-001

5. The part number listed is an assembly part number. The individual parts of the assembly might not be available separately.

6. This part is referenced for informational purposes only. It is not stocked as a repair part. Refer to the next higher assembly for a replacement part.

Page 6

Item Description Part Number Qty. Note

1 BASS MODULE ASSY, US/CANADA, 120V

BASS MODULE ASSY, JAPAN, 100V BASS MODULE ASSY, EURO, 230V

(Complete package, includes Amp Mod Assy.) 2 CLEAT, ABS 271817-001 1 3 SCREW, 4 x 1, THDF, FLHD, 82 DEG, PH 274151-16 3 4 CLIP, SPRING, KNOB 262542 1 5 KNOB, VOL CNTL, BLK 271860-001 1 6 LABEL, I/O, US/CANADA, 120V

LABEL, I/O, JAPAN, 100V

LABEL, I/O, EURO, 230V 7 SCREW, TF, 4 x 3/4, PAN, PH, BLK 273556-12 5 8 MOD ASSY, AMP, 120V

MOD ASSY, AMP, 220V, EURO

MOD ASSY, AMP, 100V JAPAN

*282451-001 *282451-002 *282451-003

272079-001 272079-002 272079-003

*307876-011 *307876-033 *307876-022

1 1 1

5 5 5

3 3,4 3,4

- XFORMER, TORROID, 105W, 15VDC, 7A TRANSFORMER, TOROID, 100V, 60Hz TRANSFORMER, TOROID, 230V, 50Hz

*Capacitor C7 on the new power supply board may need to be replaced, see Service Bulletin 271885-B4

271818-001

N/A

277613-001

Figure 1. Bass Module Assembly Exploded View

Page 7

Figure 2. Amplifier Module Assembly

Item Description Part Number Qty. Note

1 PCB ASSY, MAIN 280109-01 1 6 2 BRACKET, METAL, IC 271859 1 6 3 HEATSINK, EXTRUDED, COMP 3 271856 1 6 4 CLIP, THERMAL, THERMISTOR 272964-001 1 6 5 HEAT SPREADER, ALUM 279844-001 1 6 6 SCREW, TAPP, 6-13x.625, PAN, XRC/S 172783-10 4 7 CONN, SWITCH, POWER, 3P 273115-001 1 6 8 PCB ASSY, PS, 120V, US

PCB ASSY, PS, 100V, JAPAN PCB ASSY, PS, 240V, EURO

*Capacitor C7 on the new power supply board may need to be replaced, see Service Bulletin 271885-B4

307872-011 307872-022 307872-033

1 1 1

4 4 4

Page 8

11 12

13 14

Figure 3. Packaging Exploded View

Item

Number

1 OWNER’S GUIDE US/CANADA

OW NER ’ S GUI DE 5 LA NG 2 BA G , PO LY, 14.38 x 9.87 x 2 mi l 1 03 351 1 3 PACKING TUBE, 4.75 x 2.75 x 7.69 273522 1 4 BASS MOD ULE ASSY, US/CANADA, 120V

BASS MODULE ASSY, EUR O, 230V

BASS MODULE ASSY, JAPAN , 100V

(Compl ete package, i ncl u des Amp M od

Assy.) 5 CONTROL POD (NON-REPAIRABLE) 307874-001 1 5 6 LINE CORD, 100 V, BLK, JAPAN

LINE C ORD, 120V, BLK, US/CANADA

LINE C ORD, 220V, BLK, EURO

LINE CORD , 23 0V, BLK, UK

LINE C ORD, 240V, BLK, AUS 7 BRACKET, SAT, LEFT 271880-001 1 8 BRACKET, SAT, RGHT 271881-001 1 9 CABLE, INPUT, 3.5MM, 6FT, BLK 2719 94-001 1

10 SCREW, MACH , M 4 x 0.5, PAN 272963-08 2 11 BA G , PO LY, 14.38 x 9.87 x 2 mi l 1 03 351 1 12 FASTENER, RD, CLR, 21MM OD, PSA 273164 2 13 FEET, CLEAR, SATELLITE 178321-04 16 14 FEET, RUBBER, BRACKET 260465 4 15 SAT ASSY, BLACK/GRAY 271827-019 2 16 CARTON, RSC, P RINTED 272410 1 17 PACKING, EPS, FILLERS 272409 2

Description Part

Number

271883-001

272956

282451-001 282451-002 282451-003

264514-001 262814-001

148203 134725

284243-001

Qty. Notes

1 1

1 1 1

1 1 1 1 1

5 4,5 4,5

Page 9

ELECTRICAL PARTS LIST

Main PCB Assembly

Resistors

Reference

Designator

R1 1.00K, 0805, 1/10W, 1% 133625-1001 R4 1.00K, 0805, 1/10W, 1% 133625-1001 R2 1.00K, 0805, 1/10W, 1% 133625-1001 R3 1.00K, 0805, 1/10W, 1% 133625-1001 R5 2.00K, 0805, 1/10W, 1% 133625-2001 R6 JUMPER, CHIP, 0805 133627 R101 1.21K, 0805, 1/10W, 1% 133625-1211 R102 1.30K, 0805, 1/10W, 1% 133625-1301 R103 9.53K, 0805, 1/10W, 1% 133625-9531 R104 10.0K, 0805, 1/10W, 1% 133625-1002 R105 127K 0805, 1/10W, 1% 133625-1273 R106 127K 0805, 1/10W, 1% 133625-1273 R107 10.0K, 0805, 1/10W, 1% 133625-1002 R108 10.0K, 0805, 1/10W, 1% 133625-1002 R109 2.00K, 0805, 1/10W, 1% 133625-2001 R110 10.0K, 0805, 1/10W, 1% 133625-1002 R111 10.0K, 0805, 1/10W, 1% 133625-1002 R125 2.55K, 0805, 1/10W, 1% 133625-2551 R126 200K, 0805, 1/10W, 1% 133625-2003 R127 47.5K, 0805, 1/10W, 1% 133625-4752 R128 1.10K, 0805, 1/10W, 1% 133625-1101 R129 21.5K, 0805, 1/10W, 1% 133625-2152 R130 330 OHM, 0805, 1/10W, 1% 133625-3300 R131 6.81K, 0805, 1/10W, 1% 133625-6811 R132 17.4K, 0805, 1/10W, 1% 133625-1742 R133 1.62K, 0805, 1/10W, 1% 133625-1621 R134 2.00K, 0805, 1/10W, 1% 133625-2001 R135 1.00K, 0805, 1/10W, 1% 133625-1001 R136 1.82K, 0805, 1/10W, 1% 133625-1821 R137 10.0K, 0805, 1/10W, 1% 133625-1002 R138 2.00K, 0805, 1/10W, 1% 133625-2001 R139 1.50K, 0805, 1/10W, 1% 133625-1501 R140 1.50K, 0805, 1/10W, 1% 133625-1501 R201 1.21K, 0805, 1/10W, 1% 133625-1211 R202 1.30K, 0805, 1/10W, 1% 133625-1301 R203 9.53K, 0805, 1/10W, 1% 133625-9531 R204 127K 0805, 1/10W, 1% 133625-1273 R205 10.0K, 0805, 1/10W, 1% 133625-1002 R206 127K 0805, 1/10W, 1% 133625-1273 R207 10.0K, 0805, 1/10W, 1% 133625-1002 R208 10.0K, 0805, 1/10W, 1% 133625-1002 R209 10.0K, 0805, 1/10W, 1% 133625-1002 R210 10.0K, 0805, 1/10W, 1% 133625-1002 R211 2.00K, 0805, 1/10W, 1% 133625-2001

Description Part Number Note

Page 10

ELECTRICAL PARTS LIST

Main PCB Assembly

Resistors (continued)

Reference Designator

R225 100K, 0805, 1/10W, 1% 133625-1003 R226 100K, 0805, 1/10W, 1% 133625-1003 R227 JUMPER, CHIP, 0805 133627 R229 2.55K, 0805, 1/10W, 1% 133625-2551 R230 200K, 0805, 1/10W, 1% 133625-2003 R231 47.5K, 0805, 1/10W, 1% 133625-4752 R232 1.10K, 0805, 1/10W, 1% 133625-1101 R233 21.5K, 0805, 1/10W, 1% 133625-2152 R234 330 OHM, 0805, 1/10W, 1% 133625-3300 R235 6.81K, 0805, 1/10W, 1% 133625-6811 R236 17.4K, 0805, 1/10W, 1% 133625-1742 R237 1.62K, 0805, 1/10W, 1% 133625-1621 R238 2.00K, 0805, 1/10W, 1% 133625-2001 R239 1.00K, 0805, 1/10W, 1% 133625-1001 R240 1.82K, 0805, 1/10W, 1% 133625-1821 R241 10.0K, 0805, 1/10W, 1% 133625-1002 R242 2.00K, 0805, 1/10W, 1% 133625-2001 R243 1.50K, 0805, 1/10W, 1% 133625-1501 R244 1.50K, 0805, 1/10W, 1% 133625-1501 R301 1.00K, 0805, 1/10W, 1% 133625-1001 R301 100 OHM, 0805, 1/10W, 1% 133625-1000 4 R301 100 OHM, 0805, 1/10W, 1% 133625-1000 Euro /UK /Aus R302 1.00K, 0805, 1/10W, 1% 133625-1001 R302 100 OHM, 0805, 1/10W, 1% 133625-1000 4 R302 100 OHM, 0805, 1/10W, 1% 133625-1000 Euro /UK /Aus R305 10.0K, 0805, 1/10W, 1% 133625-1002 R306 10.0K, 0805, 1/10W, 1% 133625-1002 R307 1.20 OHMS, 2512, 1W, 5% 181895-1R20 Euro /UK /Aus R308 1.00K, 0805, 1/10W, 1% 133625-1001 R309 100 OHM, 0805, 1/10W, 1% 133625-1000 R310 100 OHM, 0805, 1/10W, 1% 133625-1000 R311 JUMPER, CHIP, 0805 133627 R311 1.00K, 0805, 1/10W, 5% 133626-1025 4 R312 JUMPER, CHIP, 0805 133627 R312 1.00K, 0805, 1/10W, 5% 133626-1025 4 R314 1.00K, 0805, 1/10W, 1% 133625-1001 R315 1.00K, 0805, 1/10W, 1% 133625-1001 R316 249 OHM, 0805, 1/10W, 1% 133625-2490 R317 249 OHM, 0805, 1/10W, 1% 133625-2490 R318 100K, 0805, 1/10W, 1% 133625-1003 R319 249 OHM, 0805, 1/10W, 1% 133625-2490 R320 1.00K, 0805, 1/10W, 1% 133625-1001 R323 487K, 0805, 1/10W, 1% 133625-4873 R324 1.21K, 0805, 1/10W, 1% 133625-1212

Description Part Number Note

Page 11

ELECTRICAL PARTS LIST

Main PCB Assembly

Resistors (continued)

Reference

Designator

R325 1.21K, 0805, 1/10W, 1% 133625-1212 R327 20.0K, 0805, 1/10W, 1% 133625-2002 R327 JUMPER, CHIP, 0805 133627 4 R327 JUMPER, CHIP, 0805 133627 Euro R328 JUMPER, CHIP, 0805 133627 R329 16.2K, 0805, 1/10W, 1% 133625-1622 R330 78.7K, 0805, 1/10W, 1% 133625-7872 R331 2.00K, 0805, 1/10W, 1% 133625-2001 R334 100K, 0805, 1/10W, 1% 133625-1003 R335 100K, 0805, 1/10W, 1% 133625-1003 R336 2.2 OHM, 0805, 1/10W, 5% 133626-2R25 R336 10 OHM, 2512, 1W, 5% 181895-10R0 Euro R337 402 OHM, 0805, 1/10W, 1% 133625-4020 R337 162 OHM, 0805, 1/10W, 1% 133625-1620 Euro R338 14.0K, 0805, 1/10W, 1% 133625-1402 R339 1.00K, 0805, 1/10W, 1% 133625-1001 R340 10.0K, 0805, 1/10W, 1% 133625-1002 R347 2.00K, 0805, 1/10W, 1% 133625-2001 R348 2.00K, 0805, 1/10W, 1% 133625-2001 R349 JUMPER, CHIP, 0805 133627 R350 JUMPER, CHIP, 0805 133627 R350 JUMPER, CHIP, 0805 133627 Euro R351 JUMPER, CHIP, 0805 133627 R351 100 OHM, 0805, 1/10W, 1% 133625-1000 4 R351 100 OHM, 0805, 1/10W, 1% 133625-1000 Euro R352 1.00K, 0805, 1/10W, 1% 133625-1001 R353 1.00K, 0805, 1/10W, 1% 133625-1001 R354 1.00K, 0805, 1/10W, 1% 133625-1001 4 R354 1.00K, 0805, 1/10W, 1% 133625-1001 Euro R355 1.00K, 0805, 1/10W, 1% 133625-1001 R356 499K, RES, 0805, 1/10W, 1% 133625-4993 4 R357 10.0K, 0805, 1/10W, 1% 133625-1002 4 R358 1.1 OHM, SMD, FUSE, 1/10W, 5% 192349-1R1A

R359 1.1 OHM, SMD, FUSE, 1/10W, 5% 192349-1R1A

R360 1.1 OHM, SMD, FUSE, 1/10W, 5% 192349-1R1A

R360 1.1 OHM, SMD, FUSE, 1/10W, 5% 192349-1R1A Euro/UK/Aus

Description Part Number Note

3,4

R361 1.1 OHM, SMD, FUSE, 1/10W, 5% 192349-1R1A

R361 1.1 OHM, SMD, FUSE, 1/10W, 5% 192349-1R1A Euro/UK/Aus

R362 JUMPER, CHIP, 0805 133627 Euro R401 100K, 0805, 1/10W, 1% 133625-1003 R402 10.0K, 0805, 1/10W, 1% 133625-1002

3,4

Page 12

ELECTRICAL PARTS LIST

Main PCB Assembly

Resistors (continued)

Reference

Designator

R403 221 OHM, 0805, 1/10W, 1% 133625-2210 R404 10.0K, 0805, 1/10W, 1% 133625-1002 R405 1.00K, 0805, 1/10W, 1% 133625-1001 R406 1.00K, 0805, 1/10W, 1% 133625-1001 R407 1.00K, 0805, 1/10W, 1% 133625-1001 R408 1.00K, 0805, 1/10W, 1% 133625-1001 R409 5.90K, 0805, 1/10W, 1% 133625-5901 R410 5.90K, 0805, 1/10W, 1% 133625-5901 R950 2.55K, 0805, 1/10W, 1% 133625-2551 R951 4.12K, 0805, 1/10W, 1% 133625-4121 R952 1.0M, 0805, 1/10W, 1% 133625-1004 R953 10.0K, 0805, 1/10W, 1% 133625-1002 R954 750 OHM, 0805, 1/10W, 1% 133625-7500 R956 88.7K, 0805, 1/10W, 1% 133625-8872 R957 1.21K, 0805, 1/10W, 1% 133625-1211 R958 10.0K, 0805, 1/10W, 1% 133625-1002 R959 1.00K, 0805, 1/10W, 1% 133625-1001 R960 36.5K, 0805, 1/10W, 1% 133625-3652 R961 36.5K, 0805, 1/10W, 1% 133625-3652 R962 1.0M, 0805, 1/10W, 1% 133625-1004 R963 26.7K, 0805, 1/10W, 1% 133625-2672 R964 750 OHM, 0805, 1/10W, 1% 133625-7500 R965 15.4K, 0805, 1/10W, 1% 133625-1542 R966 1.21K, 0805, 1/10W, 1% 133625-1213 R967 1.00K, 0805, 1/10W, 1% 133625-1001 R968 4.99K, 0805, 1/10W, 1% 133625-4991 R969 JUMPER, CHIP, 0805 133627 R970 20.0K, 0805, 1/10W, 1% 133625-2002 R971 10.0K, 0805, 1/10W, 1% 133625-1002 R972 49.9K, 0805, 1/10W, 1% 133625-4992 R973 1.21K, 0805, 1/10W, 1% 133625-1211 R974 1.00K, 0805, 1/10W, 1% 133625-1001 R975 10.0K, 0805, 1/10W, 1% 133625-1002 R976 5.90K, 0805, 1/10W, 1% 133625-5901 R977 100 OHM, 0805, 1/10W, 1% 133625-1000 R978 100K, 0805, 1/10W, 1% 133625-1003 R979 10.0K, 0805, 1/10W, 1% 133625-1002 R980 4.99K, 0805, 1/10W, 1% 133625-4991 R981 100K, 0805, 1/10W, 1% 133625-1003 R982 1.00K, 0805, 1/10W, 1% 133625-1001 R983 1.00K, 0805, 1/10W, 1% 133625-1001 R986 Potentiometer, 10K, +/- 20%, 1B 273741-001 R987 1.54K, 0805, 1/10W, 1% 133625-1541

Description Part Number Note

Page 13

ELECTRICAL PARTS LIST

Main PCB Assembly

Capacitors

Reference

Designator

C001 10000pf, MONO, 100V, 20% 180630-103 4 C002 10000pf, MONO, 100V, 20% 180630-103 4 C101 2.2uF, 1206, X7R, 10V, 20% 260361-2253 C102 .0068uF, BOX, 85C, 100V, 5% 137127-682 C103 .033uF, BOX, 85C, 63V, 5% 137127-333 C104 1000pF, 0805, COG, 50V, 5% 133622-102 C105 100pF, 0805, COG, 50V, 5% 133622-101 C110 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus C111 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus C112 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus C125 .12uF, BOX, 85C, 50V, 5% 137127-124 C126 .12uF, BOX, 85C, 50V, 5% 137127-124 C127 .18uF, BOX, 85C, 50V, 5% 137127-184 C128 .01uF, BOX, 85C, 100V, 5% 137127-103 C129 .01uF, BOX, 85C, 100V, 5% 137127-103 C130 .0015uF, BOX, 85C, 100V, 5% 137127-152 C131 .0056uF, BOX, 85C, 100V, 5% 137127-562 C132 .12uF, BOX, 85C, 50V, 5% 137127-124 C133 .12uF, BOX, 85C, 50V, 5% 137127-124 C134 1000pF, 0805, COG, 50V, 5% 133622-102 C201 2.2uF, 1206, X7R, 10V, 20% 260361-2253 C202 .0068uF, BOX, 85C, 100V, 5% 137127-682 C203 .033uF, BOX, 85C, 63V, 5% 137127-333 C204 100pF, 0805, COG, 50V, 5% 133622-101 C210 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus C225 .12uF, BOX, 85C, 50V, 5% 137127-124 C226 .12uF, BOX, 85C, 50V, 5% 137127-124 C227 .18uF, BOX, 85C, 50V, 5% 137127-184 C228 .01uF, BOX, 85C, 100V, 5% 137127-103 C229 .01uF, BOX, 85C, 100V, 5% 137127-103 C230 .0015uF, BOX, 85C, 100V, 5% 137127-152 C231 .0056uF, BOX, 85C, 100V, 5% 137127-562 C232 1000pF, 0805, COG, 50V, 5% 133622-102 C233 .12uF, BOX, 85C, 50V, 5% 137127-124 C234 .12uF, BOX, 85C, 50V, 5% 137127-124 C235 .1uF 0805, X7R, 10%, 25V 181264-104 C236 10uF, EL, SMD, 105, 25V, 20% 255071-100E C237 .1uF, 0805, X7R, 10%, 25V 181264-104 C238 10uF, EL, SMD, 105, 25V, 20% 255071-100E C239 .1uF, 0805, X7R, 10%, 25V 181264-104 C240 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus C241 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus C301 100pF, 0805, COG, 50V, 5% 133622-101 C302 3300pF, 0805, X7R, 50V, 10% 133623-332 C303 100pF, 0805, COG, 50V, 5% 133622-101 C305 3300pF, 0805, X7R, 50V, 10% 133623-332

Description Part Number Note

Page 14

ELECTRICAL PARTS LIST

Main PCB Assembly

Capacitors (continued)

Reference

Designator

C306 1uF, EL, SMD, 105, 50V, 20% 255071-1R0H C307 1uF, EL, SMD, 105, 50V, 20% 255071-1R0H C308 100pF, 0805, COG, 50V, 5% 133622-101 C309 .015uF, 0805, X7R, 50V, 10% 133623-153 Euro/UK/Aus C310 100pF, 0805, COG, 50V, 5% 133622-101 C311 10uF, EL, SMD, 105, 25V, 20% 255071-100E C312 100pF, 0805, COG, 50V, 5% 133622-101 C313 100uF, EL, SMD, 105, 25V, 20% 255071-101E C314 10uF, EL, SMD, 105, 25V, 20% 255071-100E C315 10uF, EL, SMD, 105, 25V, 20% 255071-100E C316 0.1uF, 0805, X7R, 50V 133623-104 C317 0.1uF, 0805, X7R, 50V 133623-104 C318 .022uF, 0805, X7R, 50V, 10% 133623-223 C318 .1uF, 0805, X7R, 10%, 25V 181264-104 Euro/UK/Aus C319 .022uF, 0805, X7R, 50V, 10% 133623-223 C319 .1uF, 0805, X7R, 10%, 25V 181264-104 Euro/UK/Aus C320 .47uF, 0805, X7R, 16V, 5% 196995-474 C321 .015uF, BOX, 85C, 100V, 5% 137127-153 C322 47UF, EL, SMD, 105, 25V, 20% 255071-470E C324 .015uF, BOX, 85C, 100V, 5% 137127-154 C325 0.1uF, 0805, X7R, 50V 133623-104 C326 100pF, 0805, COG, 50V, 5% 133622-101 C326 .01uF, 0805, X7R, 50V, 10% 133623-103 4 C326 .01uF, 0805, X7R, 50V, 10% 133623-103 Euro/UK/Aus C327 .1uF, BOX, 85C, 50V, 5% 137127-104 C328 100pF, 0805, COG, 50V, 5% 133622-101 C328 .01uF, 0805, X7R, 50V, 10% 133623-103 4 C329 .1uF, BOX, 85C, 50V, 5% 137127-104 C330 100pF, 0805, COG, 50V, 5% 133622-101 C330 .01uF, 0805, X7R, 50V, 10% 133623-103 4 C330 .01uF, 0805, X7R, 50V, 10% 133623-103 Euro/UK/Aus C331 100pF, 0805, COG, 50V, 5% 133622-101 C331 .01uF, 0805, X7R, 50V, 10% 133623-103 4 C331 .01uF, 0805, X7R, 50V, 10% 133623-103 Euro/UK/Aus C332 1000pF, 0805, COG, 50V, 5% 133622-102 C333 100pF, 0805, COG, 50V, 5% 133622-101 C333 1000pF, 0805, COG, 50V, 5% 133623-102 Euro/UK/Aus C333 .01uF, 0805, X7R, 50V, 10% 133623-103 4 C334 100pF, 0805, COG, 50V, 5% 133622-101 C334 1000pF, 0805, COG, 50V, 5% 133623-102 Euro/UK/Aus C334 .01uF, 0805, X7R, 50V, 10% 133623-103 4 C335 100pF, 0805, COG, 50V, 5% 133622-101 C335 1000pF, 0805, COG, 50V, 5% 133623-102 Euro/UK/Aus C335 .01uF, 0805, X7R, 50V, 10% 133623-103 4 C336 100pF, 0805, COG, 50V, 5% 133622-101

Description Part Number Note

Page 15

ELECTRICAL PARTS LIST

Main PCB Assembly

Capacitors (continued)

Reference

Designator

C336 1000pF, 0805, COG, 50V, 5% 133623-102 Euro/UK/Aus C336 .01uF, 0805, X7R, 50V, 10% 133623-103 4 C337 10uF, EL, SMD, 105CC, 25V, 20% 255071-100E C338 1000pF, 0805, COG, 50V, 5% 133622-102 C339 1000pF, 0805, COG, 50V, 5% 133622-102 C340 1000pF, 0805, COG, 50V, 5% 133622-102 C341 1000pF, 0805, COG, 50V, 5% 133622-102 4 C341 1000pF, 0805, COG, 50V, 5% 133622-102 Euro/UK/Aus C342 47uF, EL, SMD, 105CC, 25V, 20% 255071-470E 4 C342 47uF, EL, SMD, 105CC, 25V, 20% 255071-470E Euro/UK/Aus C343 1000pF, 0805, COG, 50V, 5% 133622-102 4 C343 1000pF, 0805, COG, 50V, 5% 133622-102 Euro/UK/Aus C348 .01uF, 0805, X7R, 50V, 10% 133623-103 Euro/UK/Aus C349 .01uF, 0805, X7R, 50V, 10% 133623-103 Euro/UK/Aus C350 .01uF, 0805, X7R, 50V, 10% 133623-103 Euro/UK/Aus C351 .01uF, 0805, X7R, 50V, 10% 133623-103 Euro/UK/Aus C352 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus C353 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus C354 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus C355 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus C360 .01uF, 0805, X7R, 50V, 10% 133623-103 Euro/UK/Aus C401 10uF, EL, SMD, 105C, 25V, 20% 255071-100E C402 .01uF, 0805, X7R, 50V, 10% 133623-103 C403 .01uF, 0805, X7R, 50V, 10% 133623-103 C404 1000pF, 0805, COG, 50V, 5% 133622-102 C950 10uF, EL, SMD, 105C, 25V, 20% 255071-100E C951 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus C952 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus C953 .12uF, BOX, 85C, 50V, 5% 137127-124 C954 .12uF, BOX, 85C, 50V, 5% 137127-124 4 C954 .12uF, BOX, 85C, 50V, 5% 137127-124 Euro/UK/Aus C954 Film, 16V, 0.12uF, 5%, SMT 274313-124J C955 10uF, EL, SMD, 105C, 25V, 20% 255071-100E C956 .01uF, BOX, 85C, 100V, 5% 137127-103 C957 10uF, EL, SMD, 105C, 25V, 20% 255071-100E C959 1000pF, 0805, COG, 50V, 5% 133622-102 C960 Film, 16V, 0.12uF, 5%, SMT 274313-124J C960 .12uF, BOX, 85C, 50V, 5% 137127-124 4 C960 .12uF, BOX, 85C, 50V, 5% 137127-124 Euro/UK/Aus C961 Film, 16V, 0.12uF, 5%, SMT 274313-124J C961 .12uF, BOX, 85C, 50V, 5% 137127-124 4 C961 .12uF, BOX, 85C, 50V, 5% 137127-124 Euro/UK/Aus C962 .0015uF, BOX, 85C, 100V, 5% 137127-152 C963 1000pF, 0805, COG, 50V, 5% 133622-102 C964 1000pF, 0805, COG, 50V, 5% 133622-102 C965 1000pF, 0805, COG, 50V, 5% 133622-102

Description Part Number Note

Page 16

ELECTRICAL PARTS LIST

Main PCB Assembly

Capacitors (continued)

Reference

Designator

C966 1000pF, 0805, COG, 50V, 5% 133622-102 C968 .01uF, 0805, X7R, 50V, 10% 133623-103 C969 10uF, EL, SMD, 105C, 25V, 20% 255071-100E C970 1uF, EL, SMD, 105C, 50V, 20% 255071-1R0H C971 .47uF, BOX, 85C, 50V, 5% 137127-474 C977 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus C980 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus C983 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus C988 68pF, 0603, COG, 50V, 5% 188454-680 Euro/UK/Aus

Description Part Number Note

Inductors

Reference Designator

L301 330 OHM, BEAD, FERRITE, 0805, 1.5A 267539-331 Euro/UK/Aus

Description Part Number Note

Diodes

Reference Designator

D301 SOT-23, BAV 99 147239 Euro/UK/Aus D301 ZEN, SOD-123, .5W, 5%, 10V 174265-5240 D302 SOT-23, BAV 99 147239 D303 SOT-23, BAV 99 147239 D304 SOT-23, BAV 99 147239 D305 SOT-23, BAV 99 147239 D306 SOT-23, BAV 99 147239 4 D306 SOT-23, BAV 99 147239 Euro/UK/Aus D401 DUAL, SOT-23, BAW56 180738 D402 DUAL, SOT-23, BAW56 180738 D403 SOT-23, BAV 99 147239 D951 SOT-23, BAV 70 147249 D952 SOT-23, BAV 99 147239 D954 DUAL, SOT-23, BAW56 180738 D955 SOT-23, BAV 99 147239 ZR301 ZEN, SOD-123, .5W, 5%, 10V 174265-5240 Euro/UK/Aus

Description Part Number Note

Page 17

ELECTRICAL PARTS LIST

Main PCB Assembly

Transistors

Reference

Designator

Q303 BPLR, N, 50V, 800mA, SOT23 148770 Q303 NPN, 1.3W, SOT-223 258416-001 Euro/UK/Aus Q303 NPN, SOT223, 40V, 200mA, 1W 275431 4 Q304 BPLR, P, 40V, 200mA, SOT23 148596 Q305 BPLR, N, 40V, 200mA, SOT23 146819 Q306 BPLR, P, 40V, 200mA, SOT23 148596 Q307 BPLR, P, 40V, 200mA, SOT23 148596 Q308 BPLR, N, 40V, 200mA, SOT23 146819 Q309 BPLR, N, 40V, 200mA, SOT23 146819 Q401 BPLR, N, 40V, 200mA, SOT23 146819 Q402 BPLR, P, 40V, 200mA, SOT23 148596 Q403 BPLR, P, 40V, 200mA, SOT23 148596 Q950 BPLR, N, 40V, 200mA, SOT23 146819 Q951 BPLR, P, 40V, 200mA, SOT23 148596 Q952 BPLR, P, 40V, 200mA, SOT23 148596 Q953 BPLR, N, 40V, 200mA, SOT23 146819 Q954 BPLR, P, 40V, 200mA, SOT23 148596

Description Part Number Note

Integrated Circuits

Reference Designator

U102 IC, 0P AMP QUAD, SOIC-14, NJM2059 187472 U125 IC, 0P AMP QUAD, SOIC-14, NJM2059 187472 U201 IC, 0P AMP QUAD, SOIC-14, NJM2059 187472 U3 IC, 0P AMP QUAD, SOIC-14, NJM2059 187472 U301 IC, POWER AMP, 4x45W, 25-PIN 271833-001 U401 IC, TRANS, DUAL, SOIC-16, NJM13700 188650-001 U950 IC, TRANS, DUAL, SOIC-16, NJM13700 188650-001 U951 IC, 0P AMP QUAD, SOIC-14, NJM2059 187472

Description Part Number Note

Miscellaneous

Reference Designator

J301 CONN, HEADER, 3 POS, .156 133220-03 J302 CONN, JACK, 3.5mm, PCB MNT, STEREO 177154-01 J302 CONN, JACK PHONE, 3.5MM 269841-001 4 J302 CONN, JACK PHONE, 3.5MM 269841-001 Euro/UK/Aus J305 CONN, HEADER, INLINE, PCB MNT, 4P 133220-04 J307 CONN, RCA, DUAL, PC MOUNT 272376-001 J308 CONN, MINI DIN, R/A, 9-PIN 273227-001

Description Part Number Note

Page 18

ELECTRICAL PARTS LIST

Power Supply PCB Assembly

Resistors

Reference

Designator

R1 1.00K, 0805, 1/10W, 1% 133625-1001 R2 1.00K, 0805, 1/10W, 1% 133625-1001 R3 1.00K, 0805, 1/10W, 1% 133625-1001 R4 1.00K, 0805, 1/10W, 1% 133625-1001 R5 2.00K, 0805, 1/10W, 1% 133625-2001 R6 10.0 OHM, 0805,1/10W,1% 133625-10R0 4 R6 10.0 OHM, 0805,1/10W,1% 133625-10R0 Japan R6 10.0 OHM, 0805,1/10W,1% 133625-10R0 Euro/UK/Aus R6 JUMPER, CHIP, 0805 133627 R7 412 OHMS, 0805, 1/10W, 1% 133625-4120 R8 JUMPER, CHIP,0805 133627 R9 412 OHMS, 0805, 1/10W, 1% 133625-4120 R10 JUMPER, CHIP,0805 133627 R11 10.0 OHM, 0805,1/10W,1% 133625-10R0 RT1 22K, THERMISTOR, RADIAL, 1/4W, 5% 177557 RT2 22K, THERMISTOR, RADIAL, 1/4W, 5% 177557 VR1 VARISTOR, MET OX, 275V, 140 JOULE 273545-001 VR1 VARISTOR,MET OX, 300V, 140 JOULE

VR1 VARISTOR, MET OX, 175V, 140 JOULE

Description Part Number Note

TUBING,HEAT SHRINK, .75 INCH

273545-002

267807

273545-003

267807

Euro/UK/Aus

Japan

Capacitors

Reference

Designator

C1 1.0uF, BOX, 85, 100V, 5% 137127-105 C2 .22 uF, 0805, X7R, 10%, 25V 181264-224 C3 .047uF, 0805, X7R, 50V, 10% 133623-473 C4 .1uF, 0805, X7R, 10%, 25V 181264-104 4 C4 .1uF, 0805, X7R, 10%, 25V 181264-104 Japan C4 .1uF, 0805, X7R, 10%, 25V 181264-104 Euro/UK/Aus C4 .22 uF, 0805, X7R, 10%, 25V 181264-224 C5 .1uF, 0805, X7R, 10%, 25V 181264-104 C7 39000 uF, EL, AL, 25V 260693-3931E Euro/Japan C7 33000 uFD, EL, AL, 25V, 4T 260693-3331E C8 .22UF, FILM, X2, 275VAC, 15MM 268166-224B

Description Part Number Note

Inductors

Reference

Designator

L1 Choke, Common mode, with header 277667-001 4 L1 Choke, Common mode, with header 277667-001 Japan L1 Choke, Common mode, with header 277667-001 Euro/UK/Aus

Description Part Number Note

Page 19

ELECTRICAL PARTS LIST

Power Supply PCB Assembly

Diodes

Reference Designator

BR1 RECTIFIER, BRIDGE, 8A, 400V 260684-400 D1 13V, ZEN, SOD-123, .5W, 5% 174265-5243 D2 SOT-23, BAV 99 147239

Description Part Number Note

Transistors

Reference Designator

Q1 BPLR, P, 40V, 200mA, SOT23 148596 Q2 BPLR, P, 40V, 200mA, SOT23 148596 Q3 MFET, N, 55V, TO-220FP 257359-001 Q4 BPLR, P, 40V, 200mA, SOT23 148596 Q5 BPLR, P, 40V, 200mA, SOT23 148596

Description Part Number Note

Miscellaneous

Reference Designator

F1 FUSE, 4.0A, 125V, .60X.19, SLOBLO, US

F1 FUSE, 2.0 AMPS, AXIAL, EURO 269855-02000

F1 FUSE, 4.0A, 125V, .60X.19, SLOBLO, JAPAN 135677-12

J1 CONN, HEADER, LOCKING, TOP ENTRY 193369-002

J2 CONN, HEADER, 3.96mm, 7-pin 272385-07

J3 CONN, HEADER, 3 POS, .156 133220-03

J5 CONN, AC LINE, PC MOUNT 272684-001 J5 CONN, AC LINE, PC MOUNT 277580-001 Japan/Euro J6 HEADER, SIDE ENTRY, LOCKING, ALT 272685-07A

Description Part Number Note

FUSE, 3.15A, 250V, 5.5X21mm, SLO-BLO, US

135677-12

298780-3150

Page 20

Disassembly Procedures

1. Module Assembly Removal

1.1 Remove the knob from the unit.

1.2 Peel back the label and remove it. Note: Use double side tape like 3M

double-coated tape number 655 when replacing the label or use a new label.

1.3 Remove the three silver Phillips-head screws located on the right hand side (under the label) and the five Phillips-head or T-15 Torx head screws around the heat sink fins.

1.4 Slide the electronic module back slightly.

Page 21

Disassembly Procedures

1.5 Disconnect the two connectors

shown and remove the module assembly.

Speaker Connector

Transformer Connector

1.6 Disconnect the two connectors on

the power supply PCB.

1.7 Remove the seven T-15 Torx screws shown, to remove the power supply PCB. Note: The PCB is mounted on standoffs which will become loose when removing the screws.

Note: The main PCB is glued to the heat sink assembly however it can be repaired without having to remove it.

Power supply PCB

ConnectorMain PCB

Connector

Page 22

2. Power Transformer Removal

2.1 Remove the module assembly,

perform procedure 1.

2.2 Remove the bolt at the center of the power transformer.

2.3 Remove the transformer and shield-can from the bass box.

Note: If the new power transformer has a blue mark on it, align the mark toward the PCB assembly for best performance. Refer to the service bulletin, part number 271885-B1 for more details.

Disassembly Procedures

3. Woofer Removal

3.1 The Grille on the bass module is glued

into place. The woofer is not replaceable. Replace the bass box assembly if the woofer is defective.

4. Satellite Removal

4.1 Satellite speakers are not repairable.

Page 23

Test Procedures

Test Equipment required:

1. Audio Signal Generator

2. Oscilloscope

3. Digital Multimeter

Test Set up

Connect the satellites to the output jacks on the bass module. Connect the control pod to the DIN jack on the bass module. Connect a signal generator to the audio input cable and connect the cable to the input jack on the bass module.

1. Bass Module Air Leak test

1.1 Apply a 40 mVrms, 40 Hz signal to the input of the bass module.

1.2 Set the volume knob on the control pod to maximum (fully clockwise), and set the bass control to

it’s center detent (flat) position.

1.3 Listen carefully for air leaks along all glued joints, around the heat sink, connectors and at the woofer mounting location.

1.4 Repair any air leaks around the heat sink and connectors. Replace any bass module that has air leaks around the bass box or woofer mounting location.

2. Bass Module Sweep Test

2.1 Apply a 200 mVrms, 100 Hz signal to the input of the bass module.

2.2 Set the volume knob on the control pod to maximum (fully clockwise), and set the bass control to

it’s center detent (flat) position.

2.3 Listen carefully as you sweep the bass module from 100 Hz to 300 Hz, then from 300 Hz to 100 Hz.

2.4 Listen carefully for buzzes, rattles, or other extraneous noises from the woofer, cabinet, plastic trim parts, or heat sink. A slight whooshing sound from the port (at approximately 45 Hz) is acceptable.

2.5 Repair any noise heard from around the heat sink and connectors. Replace the bass module if it has noises from the woofer or cabinet area.

Page 24

Test Procedures

3. Bass Module Tone Control Test

3.1 Apply a 90 mVrms, 100 Hz signal to the input of the bass module.

3.2 Set the volume knob on the control pod to maximum (fully clockwise), and set the bass control to

it’s center detent (flat) position.

3.3 Rotate the tone control fully clockwise and counter clockwise.

3.4 Verify that the bass level cleanly increases and decreases in level (without any scratchy noise).

4. Satellite Sweep Test

4.1 Apply a 2 Vrms, 100 Hz signal to the input of the bass module.

4.2 Set the volume knob on the control pod to maximum (fully clockwise), and set the bass control to

it’s center detent (flat) position.

4.3 Sweep the satellite speakers from 100 Hz to 3 kHz then from 3 kHz to 100 Hz.

4.4 Listen carefully for buzzes, rattles, or other extraneous noises from the Twiddler™ speakers,

plastic satellite enclosure, grille, or internal wires.

4.5 Replace any satellite that is found to be defective.

5. Satellite Air Leak Test

5.1 Apply a 2 Vrms, 200 Hz signal to the input of the bass module.

5.2 Set the volume knob on the control pod to maximum (fully clockwise), and set the bass control to

it’s center detent (flat) position.

5.3 Listen carefully for air leaks along edges of the satellite and near the grille where the Twiddler speaker is installed.

5.4 Replace any satellite that is defective.

Page 25

Test Procedures

6. Control Pod Functional Test

6.1 With the system completely set up, turn on the system using the power switch located on the bass

module.

6.2 Set the volume knob on the control pod to maximum (fully clockwise), and set the bass control to it’s center detent (flat) position.

6.3 Touch the center of the control pod . Verify that the LED turns from green to orange and orange to green with each touch.

6.4 Verify that the sound is muted and un-muted when the LED changes color and that there is no audible pop when switching from mute to un-mute.

6.5 Rotate the control pod ring, verify that the volume increases and decreases and that the ring moves smoothly.

6.6 Replace any control pod that is defective.

Page 26

Theory of Operation

The Companion® 3 Multimedia Speaker System is a 2.1 (two channel stereo with one channel subwoofer) system designed to be used as a computer sound system.

The Bass Module electronics contain signal processing circuitry and the amplifiers for the woofer and satellites. A 120 volt AC input (for US variant), 14 volt DC power supply powers the electronics. The power supply is located on a separate PC board.

The signal processing electronics in the bass module include equalizers, bass summing, TrueSpace™ processing, level compression, to prevent clipping at high volume, and protection circuitry.

The crossover frequency between bass and satellites is 300 Hz. The system is rated at 60 watts to the woofer and 18 watts to each satellite. The bass box is tuned to 45 Hz.

The following is a detailed description of the circuitry on the power supply, amp board, and remote board.

1.0 Power Supply (refer to the schematic diagram 271839)

The power supply is located on the heat sink of the module and is the smaller PCB of the two. The 120 volt AC is received from the AC inlet jack and switch at J1. The AC is fused by the 4 amp F1 fuse. VR1 protects against high voltage surges. The 120 volts is sent out to the 15 VAC, 7 amp toroid transformer mounted to the interior of the bass box on J2. The 15 VAC secondary voltage comes back into the board on J2. The 15 VAC is converted to 15-20 volts DC by bridge rectifier BR1.

Q1, Q2 and Q3 form a pre-regulator to keep the DC output voltage at 14 VDC. The 13 volt zener D1 serves as a reference to Q1. When the input AC goes one diode drop above the zener voltage, Q1 turns on. This turns off Q2, allowing Q3 to turn off, which disconnects the input rectified AC from charging C7, the 3300 uF filter capacitor above 14 volts. This makes the voltage at C7 stay at about 14 volts. C2, C3 and C4 slow down the turn on of Q3 to reduce interference from this circuit to the amplifier.

When the rectified voltage is lower than 14 volts, Q1 turns off, turning on Q2 and then Q3, allowing C7 to charge whenever the ratified voltage from BR1 is above the voltage left on C7. The 14 VDC is sent to the amplifier board over J3.

RT1 is a 22K thermistor at room temperature. It is mounted on the heat sink between BR1 and Q3. It senses the system temperature and sends a signal to the main amp board to help reduce system gain when the heat sink is getting too hot.

2.0 Main Amplifier Board (refer the schematic diagram 271838)

On sheet 1 of 3, location (D8), is the A input. U3, (D7) buffers the inputs to be sent to the remote control through J308. The remote mixes the A with the B input, on the remote, and sends the signal back to the main PCB though J308. The control pod is further described in section 3.

Page 27

Theory of Operation

2.0 Main Amplifier Board (continued) (refer the schematic diagram 271838)

The signals coming into J308 (C7) are sent to sheet 3 of 3 (L_VOL and R_VOL). Three amplifiers in U201 (D8-4) are the equalizers for the right channel and U125, (A8-4) are the equalizers for the left channel. U951 (C8-3) in conjunction with U950 (C-2), the voltage controlled amplifier, form the bass summer and dynamic bass equalizer.

The three stage equalizers for the equalizer perform the bass cutoff, mid-range cut, and high end boost, in that order. They are 4-pole Salen-Key elliptical filters.

The bass signal is formed from the two inputs summed and low pass filtered by U951. The bass level is detected by U125, D951, D952, Q950, Q951 and Q952 (B-6) forming an active peak detector. C955 and C957 filter the detected peaks to form the control voltage for the VCA in U950. When the bass level is very low, the signal is boosted by U951. U950 is in the negative feedback path for U951, and when its gain is low, U951 gain goes up, boosting the bass. U950 gain goes down when control current generated by Q952 goes down, as controlled by peak detector circuit.

Q953, Q954 and D954 (D-2) form the peak detector on the bass outputs. Peaks near the negative rail are conducted through D954 and Q953 to charge C969. Voltage on C969 is converted to a current by Q954 which controls the VCA in U950. U950 is in the negative feedback loop of U951, so when U950 gain is high, less bass is output. Near clipping detected by the peak detector is converted to high current by Q954, causing high gain in U950, reducing the gain in U951 and less bass. R980 and C969 determine the attack time of the compressor, and R981 and C969 determine the release time.

Also on sheet 3 of 3, U201 (A-3) is the virtual ground generator. The 10 volt line is divided by two R225 and R226, filtered by C970 and C235, and input to U201. The 5 volts generated by U201 is used by all the signal processing circuitry as the virtual ground reference.

The right and left outputs, EQ_R and EQ_L are sent to page 2 of 3 (B3). U102 (B3) forms the true space processing and the satellite signal compressors. TrueSpace™ processing consists of U102B and U102D which act a low pass filters with a -3 dB point of 3 kHz. This signal is subtracted from the opposite channel signal by U102A and U102C.

R204 and R105 determine how much TrueSpace signal is subtracted. The 127K compared to the 10K value of the main signal inputs gives a TrueSpace signal of -18 dB relative to the main signal. To keep the levels the same in mono conditions, the same amount of low pass filtered signal is added back to the main channel of itself, through R106 and R206.

The satellite compressor consist of D401, D402, and Q401 (D7) which detect the right and left channel level, charging C401 when the R+, R-, L+ and L- signals get near the negative rail. The compressor attack time is determined by R403, and the release time is determined by R404. When C401 charges negatively, Q402 and Q403 convert this to current which increases the gain of U401A and U401B. U401 is in the negative feedback path of U102A and U102C, and higher gain reduces the gain through the satellite channels. Therefore, high signal levels near clipping reduces the gain of the satellite channels, compressing the signals.

The compressed signals are sent to the main amplifier on sheet 1 of 3 over signals Sat_Drv_L and Sat_Drv_R. The bass signal from the bass compressor on sheet 3 of 3, BASS_DRV, is sent to two stages of bass equalization at U3B and U3D (D7). These form the 40 - 50 Hz boost, and the 100 Hz cut for the bass box equalization.

Page 28

Theory of Operation

2.0 Main Amplifier Board (continued) (refer the schematic diagram 271838)

The two satellite signals, and the bass signal are sent to the power Amp IC, U301 (C3). One channel of the power Amp IC is used for each satellite, and the bass signal uses two channels of the power chip to drive both of the woofer voice coils.

The Amp IC can provide up to 40 watts into 2 ohms per channel. The woofer coils are 2 ohms each, and 60 watts total is specified for the woofer drive. Each satellite can receive 18 watts each into their 4 ohm impedance.

The mute signal from the remote unit comes in through J308, is slowed down by C314 to prevent pops.

The 10 volts for the signal processing circuitry is generated by D301, a 10 volt zener, and Q303 in an emitter follower configuration. Q303 is specified up to 500 ma, and the entire remote and signal processor consumes about 100 ma.

For thermal protection, Q304, Q305, and Q307 (A5) process the voltage generated by the thermistor on the power supply and R337 and generate a current that goes higher as the temperature rises. This current is summed into the three compressors, reducing the gain through the system at high temperatures. This prevents the heat sink from getting too hot. R337 determines the voltage division ratio and therefore the haet sink maximum temperature.

Q308 and Q309 (D5) form a voltage detector that determines when power has reached sufficient voltage for proper power amplifier operation. If the DC voltage falls below 10 volts, the power amplifier will be muted. This prevents power up and down pops.

3.0 Control Pod Remote (refer to schematic diagram 272092)

The remote receives the A input signal from the bass module over J4. This is summed with the B input on the remote control by U2. U2 drives the volume control pot R31. The adjusted volume is sent to U4 to drive the headphone outputs J5 and connector J4 back to the bass module. U1 buffers the 5 volts reference to the sleeve of J5. J5 is a switched jack, and the switch mutes the main speakers when a headphone plug is inserted. This grounds the mute signal, which is active low.

U3 is a touch sensor switch. When the operator touches the touch sensor pad on the remote, which is connected electrically to WT1 and WT2, the QT113 chip will sense this and toggle the standby line. This changes the LED (DS1) color from yellow to green. The green led is always on, and the red led glows during standby, as driven by Q1, to mix with the green to show yellow color. U3 output also drives the standby line to the bass module power amplifier. Standby is active high on the remote, and inverted in the bass module to the active low signal required by the power amplifier.

The remote amplifiers are powered by the 10 volt supply coming in at J4 from the bass module. The virtual ground from the bass module comes in as the VCCD2 signal reference from the signal processing. ZD1 is a 4.7 volt zener which generates the local power supply voltage from the 10 volt input. R41 is the current limiting resistor for ZR1. This 4.7 volts powers U3.

At each I/O connector, resistors, capacitors, diodes, and spark gaps are present on each signal to protect against RF emissions, susceptibility, and ESD.

Page 29

SERVICE MANUAL REVISION HIST OR Y

Date Revision

10/03 00 Document released at revision

5/05 01 Later version part num b ers

5/05 02 Part number change to F1 on 6/05 03 Deletion of part numbers:

6/05 04 Part numbers for C7 and J5

9/05 05 Bass Module part number

11/05 06 Added part numbers for the

3/06 07 Changed part list notes on

4/07

6/07

8/07 09 Part number changes

3/12/08 10 Added fuse part number

6/15/09 11 Added transformer part

1/7/10 11 Changed part number 178321-

Level

Description of Change Change Driven By Pages

added to Manual

Power board.

277574-001 Main Board US lat er version

280109-001 Main Board EURO

added to include Overseas

art numbers.

changed becaus e of manufacturin

Japan and Euro rear labels page 4. Note number 6 now

ref ers to – part is f or informational use onl Main board part number 271861-1 replaced by 280109-

01.

New part number for power supply board – 307872-011 – 120V 307872-022 – 100V 307872-033 – 240V

Mod Assembly 307876-011- 12 0V 307876-022- 10 0V 307876-033- 24 0V

Control Pod 307874-001

298780-3150

number 08 to 178321-04

location.

A ffected

Service Manual

Release

Change to Main Board, Power board and Am

chan Part number 271861-

1 should be used for

the main board for all

4,6

Part number change 271861-1 replaced by 280109-01

Power supply redesigned.

supply and Control

Two ver sions of the

Power PCB, need

two versions of the

lifier board.

Bill of Material

e at the factory

Regions

Part numbers

becam e available

Improved power

pod.

fuse.

Service Center

uest

ECN 46966 8

All All

18,28,29

5, 7

Page 30

SPECIFICATIONS AND FEATURES SUBJECT TO CHANGE WITHOUT NOTICE

Bose Corporation The Mountain Framingham Massachusetts USA 01701

P/N 271885-SM REV.11 04/2007 (H):

http://serviceops.bose.com