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Bose FREESPACE BUSINESS Service Manual

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™
FREESPACE
BUSINESS
MUSIC SYSTEM
Service Manual
©
1993 Bose Corporation

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Summary of Contents for Bose FREESPACE BUSINESS

  • Page 1 ™ FREESPACE BUSINESS MUSIC SYSTEM Service Manual © 1993 Bose Corporation...

  • Page 2: Table Of Contents

    ® 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.

  • Page 3: Safety Information

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

  • Page 4: Specifications

    SPECIFICATIONS Dimensions Module: 9.1"H x 12.6"W x 20.1"D (23.1x32x51.05 cm) Satellite: 3.75"H x 4.5"W x 4.5" D (9.5x11.4x11.4 cm) Weight Module: 37 lbs. (16.8 kg.) Satellite: 1.24 lbs. (0.56 kg.) Driver 1-8" Woofer Complement 4-2.24" Twiddlers™ Finish Module: Black or white,scratch-resistant,satin-finished vinyl Satellites: Black or white,painted polymer finish...
  • Page 5 PERFORMANCE SPECIFICATIONS (Continued) Dynamic 0-16 dB variable boost @ 55 Hz (level dependent) Equalization Crossover Transition 180 Hz Frequency Input Sensitivity 0.4 Vrms @1kHz produces rated power in L/R channel outputs (at full volume) 80ms ± 40 ms Turn-On Delay (Auto) 300 µVrms ±...
  • Page 6 Frequency Response Curves Bass channel frequency response curve with tone controls at min., max., and flat positions (for 30 and 200 mVrms input level) Figure 1. Bass Channel Frequency Response Curve Left/right channel frequency response with tone controls at min., max.,and flat positions.

  • Page 7: Block Diagram

    BLOCK DIAGRAM MAIN Figure 3. Main PCB (Amplifier) Block Diagram...

  • Page 8: Theory Of Operation

    FreeSpace is meant to be used in conjunction with the customer's audio source. The FreeSpace system offers the following features: Automatic turn-on/ turn-off (audio sense or signal from the customer's audio source) Automatic (Bose ® patented) dynamic equalization Bi-amplification for better power distribution to speakers...
  • Page 9 2. Differential Amplifier Audio input is at barrier strip P5, which is located on the I/O PCB Assembly (see the schematic located in the back of this manual). This connects directly to the left and right differential amplifier buffers on the Main PCB. This stage neatly accomplishes several functions: provides rejection of common-mode interference (like hum) that might be picked up by the long audio cable between the FreeSpace™...
  • Page 10 7. Automatic Dynamic Loudness ® In order to compensate for the ear’s loss of bass response at low listening levels, a Bose patented automatic loudness circuit is employed. This circuit automatically senses the volume level of the incoming audio signal, and properly adjusts the amount of low frequency bass boost.
  • Page 11 The basic concept behind Class G operation is simple. It takes advantage of the fact that music, even at loud volume settings, has only brief moments where peak voltage from the amplifier is needed. Unfortunately, with conventional Class B amplifiers, this peak voltage is always supplied to the output transistors and most of the time is wasted as heat.
  • Page 12 This is achieved with the use of a .12 Ω resistor (R313 for right channel) in series with each amplifier output. Under normal conditions, peak current to the 8 Ω speakers should never exceed 3.5 amperes. If current flow exceeds 4.5 amperes, then Q309 will conduct and trigger monostable multivibrator circuit U401 (pins 1,2 and 3).
  • Page 13 NOTES FOR FUTURE REFERENCE...

  • Page 14: Disassembly/Assembly Procedures

    DISASSEMBLY/ ASSEMBLY PROCEDURES NOTE: Figure numbers of exploded views will be referred to throughout these procedures. Certain parts will be referenced. The item number in each figure which corresponds to the part will be enclosed in parentheses-i.e.-rod cover (4). 1. Mounting Hardware Removal 2.
  • Page 15 4. Junction Box Cover Replacement 7. Tone Control PCB Assembly Removal A. Position the junction box cover (8) over the 4 NOTE: Refer to Figure 4 for Procedures 7 and screws (9) still secured to the junction box (7). 8 unless otherwise specified. Lower the cover into place.
  • Page 16 10. Woofer Replacement NOTE: If no further troubleshooting is required,restore any connections that may have been desoldered or disconnected. A. Cut the wires connected to the woofer terminals as close to the terminals as possible. (These wires are the woofer connection cable C.
  • Page 17 C. Lower the PCB through its slot on the rear panel (Figure 6,Item 3). D. If no further troubleshooting is required,re- install the panel assembly (Procedure 6),junction box cover (Procedure 4),and mounting hardware D. Secure the PCB to the panel with 2 11/32" hex (Procedure 2).
  • Page 18 Satellite Procedures B. Connect the red wire to the positive (+) twiddler terminal and the black wire to the negative (-) twiddler terminal. NOTE: Refer to Figure 7 for an exploded view of the satellite. Certain parts will be referred to in these procedures.

  • Page 19: Troubleshooting Tip For Hum And Rfi Removal

    TROUBLESHOOTING TIP FOR HUM AND RFI REMOVAL Hum and RFI (Radio Frequency Interference) are the most common problems when using unbalanced signal sources and long signal leads. Once you have connected all equipment properly and made all chassis grounds,adjust the BALANCE TRIM potentiometer located in the junction box. See the figure below for reference.

  • Page 20: Test Procedures

    TEST PROCEDURES 1. Sweep Test Satellite Test Procedures NOTE: This test can be performed with a fully NOTE: Use these procedures only when assembled bass module. satellites come in to be serviced (without the bass module). A. Connect an oscillator to the module’s L/R audio input terminals.
  • Page 21 3. Frequency Response of L/R (Twiddler) Channels 4. Twiddler Power Output Test NOTE: This test can be performed with a fully NOTE: This test can be performed with a fully assembled module. assembled module. Refer to the second note in Procedure 3 before making any connections.
  • Page 22 C. Connect a distortion meter across either the A. Make up a temporary set of connections to the left or right twiddler output terminals. The woofer output connector J303 (disconnect from distortion should be less than 3.0% THD. the woofer). The positive wire should be connected to pin 2 and the negative wire should be connected to pin 1 .
  • Page 23 2. System Sweep Test 11. Woofer Power Output Test A. Use the procedures already given for the NOTE: Use the same test setup as Procedure satellites and the module,except use 185 mVrms 9,except remove the dB meter. for both parts of the test. Use Procedure #1 under Satellite Test Procedures and Procedure #1 Ω...

  • Page 24: Parts Lists And Exploded Views

    PARTS LISTS AND EXPLODED VIEWS The following section contains parts lists and exploded views for the FreeSpace™ business music system. The parts lists are broken down as follows: -Bass Module Parts List and Exploded View. -Bass Module Packaging Parts List and Exploded View -Satellite Parts List and Exploded View.
  • Page 25 PARTS LIST NOTES 1. This part is not normally available from Customer Service. Approval from the Field Service Manager is required before ordering. 2. Refer to the Panel Assembly Parts List for parts located on the panel. 3. Refer to the Electrical Parts List for components located on this PCB. Components with 500 series designators are located on this PCB.
  • Page 26 Bass Module Parts List (Figure 4) Item Description Part Number Qty. See Note Number Module Panel Assembly-120V 145530-1 Panel Assembly-230V 145530-2 Panel Assembly-100V 145530-3 Screw-HIRS, 137527-16 8-10x1,PAN,XREC/SQ Screw- 148658 Mach.,1/4 x 20,Hex Wshr. Hd. Cover-Rod 145983 Strap-Mounting,Black 145554-01 Strap-Mounting,White 145554-02 Cover-Terminal Block,Yellow 147524-32 Box-Junction,Black...
  • Page 27 Bass Module Parts List (Continued) Item Description Part Number Qty. See Note Number Module Woofer-8" 146928 Woofer-8" (alternate) 142322 Cable-Woofer Connection 147795 Knob 136139 Nut-Hex 137446 Washer-1/4",Steel 131263-25 PCB Assembly-Tone Control 145525 Label-Tone Control 138446...
  • Page 28 Figure 4. Bass Module Exploded View...
  • Page 29 Bass Module Packaging Parts List (Figure 5) Item Description Part Number Qty. See Note Number Carton Bracket-Wall Mount,Black 145553-01 Volume Control-Arctic White 135209-2 (US) Volume Control-Arctic White 170245-01 (Eur.) Polybag (Volume Control) 143393 Insert-Diecut,Freespace 149240 Literature Kit-120V 146091-1 Literature Kit-230V 146091-2 Literature Kit-100V 146091-3...
  • Page 30 Figure 5. Bass Module Packaging Exploded View...
  • Page 31 Panel Assembly Parts List (Figure 6) Item Description Part Number Qty. See Note Number Assembly Heatsink 145536 Gasket-Heatsink 145537 Panel-Mounting,Rear 144495-01 Screw- 139761-06 Thrd. Form,PAN,4-20 x 3/8" Connector-Barrier Strip,3P 145543-3 Gasket-Barrier Strip,3 Term. 145544 Screw- 146093-12 Tapp,6-32 x 3/4, PAN, XREC Transformer-Keep Alive, 145527 EI41/120V,T1 (US,Japan)
  • Page 32 Figure 6. Panel Assembly Exploded View...
  • Page 33 Satellite Parts List (Figure 7) Item Description Part Number Qty. See Note Number Satellite Logo-White on Black 123981-1A2 Logo-White on Grey 123981-1B3 Nut-Push On,.078 125786 Grille-Black 145401-1 Grille-White 145401-2 Grille Insert-Left,Black 142080-11 Grille Insert-Right,Black 142080-21 Grille Frame-Left,Black 145396-11 Grille Frame-Left,White 145396-13 Grille Frame-Right,Black 145396-21...
  • Page 34 Figure 7. Satellite Exploded View...
  • Page 35 Satellite Packaging Parts List (Figure 8) Item Description Part Number Qty. See Note Number Carton Polybag (Satellite Parts) 144677 Tape-Bag,Sealing 148425 Bracket-Black 149303-1 Bracket-White 149303-2 Wrench-Allen,3/32 141109 Sheet-Instruction 145824 Packing-Divider 145395 Packing-Tape Tube 146468 Packing-Insert 145399 Carton-Satellites 145398 Figure 8. Satellite Packaging Exploded View...
  • Page 36 Electrical and Mechanical Parts Lists The next section of this manual contains the electrical and mechanical parts lists. The electrical parts list contains all electrical components located on the Main PCB,Tone Control PCB and I/O PCB Assemblies. Each board has a specific series of reference designators which are coded as follows: •...
  • Page 37 NOTES FOR FUTURE REFERENCE...
  • Page 38 Electrical Parts List Resistors Reference Description Part Number See Note Designator R1-5 100Ω,5%,1/4W, 121243-1211015 52 mm,CF R6,7 10Ω,1%,1/4W, 121245-22110R0 R101,131 4.7kΩ,5%,1/4W, 141760 R102,132,312, 220Ω,5%,1/4W, 141750 337,362,376,377, R103,133,501, 8.2kΩ,5%,1/4W, 141815 502,508,509 R105,135,232, 10kΩ,5%,1/4W, 141742 239,240,309,315, 334,340,358,363, 411,415,417,421, 424,434,435,439, 517,521-523, 525-527 R106,136,258,427 5.6kΩ,5%,1/4W, 141765 R109,139 510Ω,5%,1/4W,...
  • Page 39 Resistors (Continued) Reference Description Part Number See Note Designator R126,156,207, 20kΩ,5%,1/4W, 141749 218,233,235,402, 404,405,410,413, R130,160,255, 5.1kΩ,5%,1/4W, 141762 325,350,373,414, 425,515,518 R201-204,212-215 1kΩ,1%,1/4W, 141771 R205,206,216, 20kΩ,1%,1/4W, 141775 217,251,253 R208,219 300Ω,5%,1/4W, 141754 R209,221,222, 47kΩ,5%,1/4W, 141761 224,229,429 R228 56Ω,5%,1/4W, 141764 R234 750kΩ,5%,1/4W, 141768 R236 2.4kΩ,5%,1/4W, 141751 R237...
  • Page 40 Resistors (Continued) Reference Description Part Number See Note Designator 51Ω,5%,1/4W, 141287 Fusing R303,319,328,345 R304,320,329, 390Ω,5%,1/4W, 141759 346,422 5.1Ω,5%,1/4W, 141288 Fusing R305,321,330, 347,355,370 200Ω,5%,1/2W, 141290 Fusing R307,322,332,342 R311,336,361,516 200Ω,5%,1/4W, 141747 R313,338 0.12Ω,5%,1W, 141783 Metal Oxide R351,367 33kΩ,5%,1/4W, 141757 100Ω,5%,1/4W, 141286 Fusing R353,368 R354,369 270Ω,5%,1/4W,...
  • Page 41 Capacitors Reference Description Part Number See Note Designator C1-5 0.001µF,5%,Film 137123-102 C6-8 0.033µF,5%,Film 137123-333 C101,102,114,115 0.056µF,5%,50V, 171319 Mylar C104,105,117,118 0.12µF,5%,50V, 141732 Mylar 0.047µF,5%,50V, C107,108,120, 141811 121,503,504,508, Mylar C109,110,122,123 0.082µF,5%,50V, 141738 Mylar C111,124,203, 0.001µF,5%,50V, 141705 204,209,210,215 Mylar C112,125 470pF,5%,125V, 171321 Polystyrene C113,126,206, 2.2µF,20%,50V, 141693...
  • Page 42 Capacitors (Continued) C301,305,307, 0.1µF,+80/-20%, 141809 311,313,317,410, 50V,Ceramic 411,413-416,421, 511,512 C302,304,308, 4700pF,5%,100V, 141739 310,314,316 Mylar C319-324 330pF,10%,50V, 141700 Ceramic C406 470µF,20%,35V, 141690 Electrolytic C407 220µF,20%,35V, 141688 Electrolytic C412 0.01µF,125VA, 141704 Ceramic C417,418 10000µF,20%, 141248 50V,Electrolytic C419,420 4700µF,20%,25V, 141247 Electrolytic C501,506 0.0012µF,5%,50V, 141810 Mylar C502,507...
  • Page 43 Transistors Reference Description Part Number See Note Designator Q201,305,306, NPN,2SC1815GR, 141260 311,320,321,326, T0-92 335,336,340,401, 402,404-407,501 Q202,203,301, PNP,2SA1015GR, 141263 309,310,313,316, T0-92 324,325,328,331, 339,342,403,409, 410,502 PNP,2SB549Q 112287 Q302,317,332 PNP,BD244B, 137652 T0-220 Q303,308,318, PNP,2SA817A, 141262 T0-92 Q304,319,334 NPN,BD243B, 137651 T0-220 Q307,315,322, NPN,2SD415Q 112886 Q312,327,341 NPN,2SC1627A, 141259...
  • Page 44 Integrated Circuits Reference Description Part Number See Note Designator REG1 Regulator-15V,1A, 107410 ,TO-220 NJM7815A 15V,1A, LM7815CT TO-220 15V,1A, LM7815 TO-220AB REG2 Regulator-1A,- 107385 NJM7915A, TO-220 -15V LM7915CT TO-220 1A,- UA7915UC TO-220 U101-104, Op Amp-IC4559 108568 201-203,207,208, 401,501,503 IC4558 127373 U204 Sensor-Signal 141266 Level,NJM2072,...
  • Page 45 Connectors Reference Description Part Number See Note Designator P1,2,4 Header-Right 134290-02 Angle,2 pin,4.0mm Header-Right 145402-04 Angle,4 pin,2.5mm Housing Assy., 171322 2+2 pin,210mm, Left channel Housing Assy., 171323 2+2 pin,265mm, Right channel J101 Header-7 pin, 141792 I-type,B7B-XH-A J201 Housing Assy., 171324 4+4 pin,445mm J201 Header-4 pin,...
  • Page 46 Mechanical Parts Lists I/O PCB Assembly Mechanical Parts List (Figure 9) Item Description Part Number Qty. See Note Number Plate-I/O 145538 Gasket-I/O Plate 145545 Connector-Barrier Strip,8 pos. 145542-8 Screw- 146093-12 Tapp,6-32 x 3/4,PAN,XREC Figure 9. I/O PCB Assembly Exploded View (Mechanical Parts)
  • Page 47 NOTE The parts given in this list are not illustrated. However,the description column provides location information for these parts. Main PCB Assembly Mechanical Parts List Item Description Part Number Qty. See Note Number Fuse Holder-5x20 mm 171334 [F1] Heatsink 141661 [REG1 and REG2 are attached to it] Heatsink Coupler (Double) 141271...

  • Page 48: Schematics And Pcb Layouts

    SCHEMATICS AND PCB LAYOUTS Three schematics are enclosed backed by their respective PCB layouts. The following PCB assemblies are contained here: I/O PCB schematic backed by its PCB layout and etch layer Main PCB schematic backed by its PCB layout and etch layer Tone Control PCB schematic backed by its PCB layout and etch layer...
  • Page 49 NOTES FOR FUTURE REFERENCE...
  • Page 50 SPECIFICATIONS AND FEATURES SUBJECT TO CHANGE WITHOUT NOTICE 1/93: REV.0 Bose Corporation The Mountain Framingham, Massachusetts USA 01701 P/N 149524 FOR TECHNICAL ASSISTANCE OR PARTS ORDERING,CALL 800-367-4008...

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