Safety Information .....................................................................................................................................................3
Part List Notes ...........................................................................................................................................................6
Packaging Part List, L1 Model I Power Stand (see Figure 1).................................................................................7
Figure 1. L1 Model I Power Stand Packaging V iew.....................................................................................................8
Packaging Part List, L1 Model I Line Array (see Figure 2) .....................................................................................9
Figure 2. L1 Model I Line Array Packaging View.........................................................................................................9
Packaging Part List, B1 Bass Module (see Figure 3) ...........................................................................................10
Main Part List, L1 Model I Power Stand (see Figure 4) ........................................................................................11
Figure 4. L1 Model I Power Stand Exploded V iew.....................................................................................................12
Main Part List, L1 Model I Power Box (see Figure 5) ...........................................................................................13
Figure 5. L1 Model I Power Box Exploded View .......................................................................................................13
Main Part List, L1 Model I Input Panel Assembly (see Figure 6) .........................................................................14
Figure 6. L1 Model I Input Panel Assembly Exploded View ......................................................................................15
Main Part List, Remote Control Assembly (see Figure 7) ....................................................................................16
Figure 7. Remote Control Assembly Exploded V iew .................................................................................................16
Main Part List, L1 Model I Upper and Lower Line Source Arrays (see Figure 8) ...............................................17
Figure 8. L1 Model I Line Array Exploded View.........................................................................................................18
Main Part List, B1 Bass Module Exploded View (see Figure 9)...........................................................................19
Electrical Part Lists ........................................................................................................................................... 20-69
Figure 1 1. L1 Model I Power Stand Block Diagram ...................................................................................................78
T est Procedures ................................................................................................................................................ 79-85
Figure 12.
L1 Model I Power Stand Sof tware Update Procedure ..........................................................................................90
Theory of Operation ......................................................................................................................................... 91-111
Line Array Wiring Diagram ................................................................................................................................134
IC Diagrams ...................................................................................................................................................141-153
Service Manual Revision History ......................................................................................................................154
Amplifier Output Test Cable Wiring Diagram ............................................................................................86
®
Model I Power Stand ............................................6
2
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.
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 American National Standards
Institute (ANSI) C101.1 "Leakage Current for Appliances" and Underwriters Laboratories (UL)
6500 / IEC 60056 paragraph 9.1.1. With the unit AC switch first in the ON position and then in
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 outlet and repeat 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.
CAUTION: The Bose® L1® Model I System contains no user-serviceable parts. To pre-
vent warranty infractions, refer servicing to warranty service stations or factory service.
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.
3
Specifications
MECHANICAL
External Dimensions
®
Model I Cylindrical Radiator®:Height: 86.0 in (2184 mm)
L1
Width: 3.5 in (89 mm)
Depth: 4.0 in (105 mm)
L1 Model I Power Stand:Height: 5.0 in (127 mm)
Width: 26.0 in (660 mm)
Depth: 26.0 in (660 mm)
B1 Bass Module:Height: 15.3 in (380 mm)
Width: 10.3 in (257 mm)
Depth: 18.0 in (457 mm)
R1 Remote:Height:1.6 in (40 mm)
Width: 2.8 in (71 mm)
Depth: 5.6 in (141 mm)
Weight
L1 Model I Cylindrical Radiator:14.5 lbs (6 kg) Upper
16.0 lbs (7 kg) Lower
L1 Model I Power Stand:35 lbs (16 kg)
B1 Bass Module:25 lbs (12 kg)
R1 Remote:0.6 lbs (0.27 kg)
Transducer Complement
L1 Model I Cylindrical Radiator:24 x 2.25 in (57 mm) Drivers - 4 ohms
B1 Bass Module:2 x 5.25 in (133 mm) Drivers - 8 ohms
ACOUSTICAL
Frequency Response
L1 Model I Cylindrical Radiator:120 Hz to 15 kHz
B1 Bass Module:40 Hz to 250 Hz
L1 Model I System (with system EQ):40 Hz to 15 kHz
Port Tuning
L1 Model I Cylindrical Radiator:114 Hz
B1 Bass Module:44 Hz
4
Specifications
ELECTRICAL
Impedance
®
L1
Model I Cylindrical Radiator®:4 ohms nominal, both sections in parallel
Lower Model I line array section:8 ohms nominal
Upper Model I line array section:8 ohms nominal
B1 Bass module (optional):8 ohms nominal
System Power Handling
(Continuous full power per IEC-268-5 for duration of 100 hours)
L1 Model I Cylindrical Radiator:250 W
B1 Bass module:125 W
Unbal TS, -10dBu (nom) +3dBu max
Efficiency:80% minimum
THD at Rated Power:1.0% Max @ 30 Hz - 15 KHz @ 4 ohms/Ch.
THD at -3dB (~125W):0.25% Max @ 30 Hz - 15 KHz @ 4 ohms/Ch.
S/N ratio:-80dB minimum, referenced to full power
Frequency Response:40 Hz-15 KHz +/-3 dB @ R load = 4-16 ohms
Thermal:Operate 2Ch. x 83 W Continuous @ 4 ohms,
50°C ambient with No Shut-Down
AC Power Rating:US/Canada: 100-127V, 50/60Hz 1000W
International: 220-240V, 50/60Hz 1000W
Max Power Draw:1400 watts 50/60 Hz
Peak In Rush Current:US/Canada: 32 A @ 120V, 60 Hz
International: 16A @ 230V, 60Hz
Power Supply Voltages:Channels 1 and 2 SMPS 27.5 VDC +/-2%
Auxiliary supply #1 +5 VDC/1 A +/- 3%
Auxiliary supply #2 +3.3 VDC/1.5 A +/- 3%
Fan 1.2.3.4 Voltage:+24 VDC +/-1V
5
Differences between the PS1 Power Stand and the L1® Model I Power Stand
The L1 Model I Power St and is very similar to the Personalized Amplification System PS1 Power
Stand. There are some significant differences, however:
1. The line array is now powered by one 250W amplifier instead of two. The two line array
sections (upper and lower) are now wired in parallel and powered by a single amplifier. Each
line array section impedance is now 8 ohms, with the two sections wired in parallel, for a total of
4 ohms in operation. The line arrays sections used with the PS1 power stand were 4 ohms
each. Due to optimization of the speaker to the amplifier, the overall output level of the L1 Model
I system is virtually the same as the PAS system. There is a mechanical stop to prevent users
from plugging a PAS line array into an L1 Model I power stand. Users can however insert an L1
Model I line array into a PAS PS1 Power Stand. This will not harm the unit, but will result in a
lower output level (~1.5 dB less).
2. The Amp 1 IN, Amp 2 IN, Amp 3 IN, All Amps IN, Amp 1 OUT and Amp 2 OUT jacks have
been removed from the L1 Model I Power Stand. These connectors were originally intended for
users to access the power stand amplifiers in a stand-alone fashion. They were rarely used on
the PS1 Power Stand.
CAUTION: Be sure to use only L1 Model I upper and lower line array sections with the L1 Model
I power stand. It is physically possible to connect a PAS upper line array section onto an L1
Model I lower line array section. Doing so will result in an excessive current drain on the L1
Model I power stand amplifier board, possibly causing a failure.
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.
W arranty
The Bose
The L1 Model I line array and the B1 bass module are covered by a 5-year limited warranty.
®
L1 Model I System electronics are covered by a limited 1-year transferable warranty.
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 located 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. 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.
6
Packaging Part List
L1® Model I Power St and (see Figure 1)
Item
Number
- Carton Kit, Includes Carton,
Cardboard A & B, and Packing
PE Foams 1 – 4.
1 PS1 Filler Card Board - A 275437 1450-7370+1 2
2 Carry Bag for Power Stand 275468 8901-4920-0 1
3 Poly Bag for Carry Bag - 1497-7572-0 1 4
4 Poly Bag - 1497-1062-0 1 4
5 Owner’s Manual, DVD
9 PS1 Filler PE - Foam 4 275442 1493-0421+3 2
10 PS1 Filler PE - Foam 2 275440 1493-0411+3 1
11 L1 Model I Power Stand Assy - REF 1 4
12 Poly Bag for Power Stand - 1497-7572-0 1 4
13 PS1 Filler PE - Foam 3 275441 1493-0401+3 2
14 R1 Remote Control Assembly
w/packaging
15 PS1 Filler PE - Foam 1 275439 1493-0391+3 1
16 PS1 Filler Card Board - B 275438 1450-7410+4 4
17 Carton, PS1 Power Stand 275846 1436-4302+3-3 1
18 Line Cord, 120V, 15A, US/Can 035393 - 1 3
Line Cord, 230V, 15A, Euro 283048 SVC-PS121+AAC 1 Line Cord, 230V, 15A, Aus 283623 7012-5430+0 1 Line Cord, 230V, 15A, UK 283624 7010-9810+0 1
Line Cord, 100V, 15A, Japan 298167 SVC-PS101+AAC 1
19 Poly Bag for Fuse - 1497-0332-0 1 4
20 Fuse, T15A, 125V/250V,
6.3x32mm, US/Can/Japan
Fuse, T10A, 125V/250V,
6.3x32mm, Euro/UK/Aus
Description Bose® Part
Number
307131 SVC-PS111+CKIT 1
306618
306316-01
035394 SVC-PS111+REM 1
307732 5120-0023+0 1 3
279425 5120-0170+0 1
Vendor Part
Number
8901-5080+1
4115-0009+0
Qty. Note
1
7
1
2
3
4
5
6
9
7
18
19
20
7
8
9
10
11
12
13
13
7
14
15
1
Figure 1. L1
16
17
®
Model I Power Stand Packaging View
8
4x
Packaging Part List
L1® Model I Line Array (see Figure 2)
Item
Number
- Carton Kit, Includes Cardboard
Description Bose® Part
Number
307132 - 1
Vendor Part
Number
Qty. Note
A and B, and Packing PE
Foams 1 - 5
1 Packing PE Foam 4 307719 1493- 0461-0 1
2 Packing PE Foam 2 307717 1493- 0441-0 2
3 Poly Bag - 1497-7562-0 2 4
4 Packing PE Foam 1 307716 1493- 0431-0 1
5 Packing Cardboard A 307720 1450-7380-0 2
6 Packing PE Foam 5 306626 1493- 0471-0 1
7 Line Sour ce Lower Assembly REF - 1
8 Line Source Upper Assembly REF - 1
9 Line Source Carry Bag 275470 - 2
10 Poly Bag for Carry Bag - - 2 4
11 Packing Cardboard B 306628 1450-7400-0 1
12 Packing PE Foam 3 307718 1493-0451-0 1
13 Carton, no fillers 306629 1437-9702+1-3 1
1
5
2
3
3
4
2
6
7
8
9
10
11
12
5
Figure 2. L1 Model I Line Array Packaging View
9
13
Packaging Part List
B1 Bass Module (see Figure 3)
Item
Number
Description Bose® Part
Number
Vendor Part
Number
Qty. Note
- Carton Kit – Includes All Fillers 307133 - 1
1 Carton Filler, PE Foam 303838 - 2
2 Poly Bag, 12x16x49” - 1497-4552-0 1
3 B1 Bass Module REF - 1
4 Bass Module Carton, No Fillers 303837 - 1
5 Bubble Bag for Cable - 1497-1122-0 1
6 4-Wire Speakon Cable
035404 7012-6620-2 1
Assembly
7 Poly Bag for Instruction Manual - 1497-1062-0 1
8 Owner's Manual 303154 - 1
- Carry Bag for Bass Module 035025 - 1
5
2x
6
7
8
1
2
3
4
Figure 3. B1 Bass Module Packaging View
10
Main Part List
L1® Model I Power St and (see Figure 4)
Item
Number
1 Screw, Mach, M4x14, Blk, Zinc 276999 2904-4014-3000 19
2 Screw, Mach, M4x8, Blk, Zinc 276997 2904-4008-3000 4
3 Housing, Lower, Power Stand 264035 SVC-PS111+LCAB 1
4 Power Sta nd Ca vit y Assem bly,
consists of:
Plate, Base, Power Stand - 1404-9601-0 1 4
PS1 Slide Spring - 2510-3611-0 1 4
Screw, Flat-CS, M2.6x8, BZ - 2901-2608-3001 4 4
Screw, Mach, M6x35mm, Blk, Zinc,
Slide Block
Screw, Mach, M4x8 276997 2904-4008-3000 2 4
Cavity, Aluminum, Power Stand - 4135-3731-0 1 4
Guide, Cavity, Power Stand - 4135-3741-0 1 4
Latch, Power Stand - 4135-3751-0 1 4
Slide, Power Stand - 4135-3761-0 1 4
Plate, Latch, Power Stan d - 4135-3771-0 1 4
Post, Copper, Power Stand - 4135-3971-0 1 4
Pedal, Foot, Power stand - 4154-6921-0 1 4
Screw, Mach, M4x14, Blk, Zinc 276999 2904-4014-3000 4 Screw, Mach, M3x8, Blk, Latch Plate - 2901-3008-3000 4 4
Gasket, EVA, 5x500mm - 4153-3331-0 2 4
5 Power Box As sembly, includes PCBs
US/Canada, 120V
Euro, UK, Aus, 230V
Japan, 100V
6 Screw, Mach, M3x10, Blk, Zinc - 2900-3010-3030 16 4
7 Housing, Upper, Power Stand 264034 1466-4801-0 1
8 Power Sta nd Prot ec ti ve Plu g 035410 4154-7251-0 1
9 Power Sta nd Foot Pe dal 264039 4154-692 1-0 1
10 DSP PCB Assembly 283364 SVC-PS111+DSP 1 2
11 MCU PCB Assembly 306284 SVC-PS111+MCU 1 2
12 Input PCB Assembly 306283 SVC-PS111+INP1 1 2
13 Input Panel Assembly, includes DSP,
MCU and Input PCBs
US/Can, 120V
Euro, UK, Aus, 230V
Japan, 100V
14 Power Stand Push Button 2639 79 2446-4901-0 4
15 Screw, Mach, M3x10, Input Panel 277004 2911-3010-3000 18
16 Power Stand V/R Knob 263986 2446-630 1-0 4
17 Power Stand Door Assy, includes: 273727 SVC-PS111+DOOR 1
US/Canada, Japan, 100/ 120V
Euro, UK, A us, 220- 240V
Note: Item 3, D-Class Am p PCB As se m bly , has bee n chan ged to part number 312945 for all
voltage variants starting with DOM 0061
3/2/10 use part num ber 306282.
D101 LL4148, SM 4804-1480+3 4
D102 LL4148, SM 4804-1480+3 4
D103 LL4148, SM 4804-1480+3 4
D104 LL4148, SM 4804-1480+3 4
D105 LL4148, SM 4804-1480+3 4
D106 LL4148, SM 4804-1480+3 4
D107 LL4148, SM 4804-1480+3 4
D108 LL4148, SM 4804-1480+3 4
D109 LL4148, SM 4804-1480+3 4
D110 LL4148, SM 4804-1480+3 4
D113 LL4148, SM 4804-1480+3 4
D114 LL4148, SM 4804-1480+3 4
D115 LL4148, SM 4804-1480+3 4
D116 LL4148, SM 4804-1480+3 4
D117 LL4148, SM 4804-1480+3 4
D118 LL4148, SM 4804-1480+3 4
D119 LL4148, SM 4804-1480+3 4
D120 LL4148, SM 4804-1480+3 4
D121 LL4148, SM 4804-1480+3 4
D122 LL4148, SM 4804-1480+3 4
D123 LL4148, SM 4804-1480+3 4
D124 LL4148, SM 4804-1480+3 4
D125 LL4148, SM 4804-1480+3 4
D126 LL4148, SM 4804-1480+3 4
D127 LL4148, SM 4804-1480+3 4
D127A LL4148, SM 4804-1480+3 4
D128 LL4148, SM 4804-1480+3 4
D128A LL4148, SM 4804-1480+3 4
D129 LL4148, SM 4804-1480+3 4
D130 LL4148, SM 4804-1480+3 4
D131 LL4148, SM 4804-1480+3 4
D132 LL4148, SM 4804-1480+3 4
D133 LL4148, SM 4804-1480+3 4
D134 LL4148, SM 4804-1480+3 4
D135 LL4148, SM 4804-1480+3 4
D136 LL4148, SM 4804-1480+3 4
D137 LL4148, SM 4804-1480+3 4
D138 LL4148, SM 4804-1480+3 4
D139 LL4148, SM 4804-1480+3 4
D140 LL4148, SM 4804-1480+3 4
D141 LL4148, SM 4804-1480+3 4
D142 LL4148, SM 4804-1480+3 4
D381 LL4148, SM 4804-1480+3 4
D382 LL4148, SM 4804-1480+3 4
D383 LL4148, SM 4804-1480+3 4
D384 LL4148, SM 4804-1480+3 4
D385 LL4148, SM 4804-1480+3 4
D386 LL4148, SM 4804-1480+3 4
D387 LL4148, SM 4804-1480+3 4
D388 LL4148, SM 4804-1480+3 4
D389 LL4148, SM 4804-1480+3 4
D390 LL4148, SM 4804-1480+3 4
D391 LL4148, SM 4804-1480+3 4
D392 LL4148, SM 4804-1480+3 4
D393 LL4148, SM 4804-1480+3 4
Description Vendor Part
Number
Diodes
Description Vendor Part
Number
35
Note
Note
Electrical Part List
Digital Signal Processor (DSP) PCB Assembly
Diodes
Reference
Designator
D394 LL4148, SM 4804-1480+3 4
D395 LL4148, SM 4804-1480+3 4
D396 LL4148, SM 4804-1480+3 4
D431 LL4148, SM 4804-1480+3 4
D432 LL4148, SM 4804-1480+3 4
LED461 LED, 3MM, GREEN, SP 3700-2489+G 4
Reference
Designator
U381 NJM2068M-#ZZZB, DUAL OP AMP 3130-6890+0 4
U382 NJM2068M-#ZZZB, DUAL OP AMP 3130-6890+0 4
U383 NJM2068M-#ZZZB, DUAL OP AMP 3130-6890+0 4
U384 NJM2068M-#ZZZB, DUAL OP AMP 3130-6890+0 4
U385 A/ D, 192KHZ, CS5361-KSZ, S01C24L 3132-0240+0 4
U386 A/ D, 192KHZ, CS5361-KSZ, S01C24L 3132-0240+0 4
U387 24BI T DAC W/VO L CTRL, CS4392-KZZ,
D341 LL4148, SM 4804-1480+3 4
D342 LL4148, SM 4804-1480+3 4
D343 LL4148, SM 4804-1480+3 4
D344 LL4148, SM 4804-1480+3 4
D345 LL4148, SM 4804-1480+3 4
D346 LL4148, SM 4804-1480+3 4
D347 LL4148, SM 4804-1480+3 4
D348 LL4148, SM 4804-1480+3 4
Model I Power Stand Electronics Module with Top Cover Removed
70
Disassembly Procedures
L1® Model I Power Stand
Note: Refer to Figure 10 for the following
procedures.
1. Lower Housing Removal
1.1 Place the power stand on a soft surface
so that the line array opening faces down.
1.2 Using a Phillips-head screwdriver,
remove the 19 screws that secure the lower
housing to the upper housing. Lift off the
lower housing.
2. Amplifier Housing Removal
2.1 Perform procedure 1.
2.2 Make a note of the wiring, and discon-
nect the wiring harnesses and connectors
that run to the amplifier housing. The amplifier housing is the large metal box with the
four fans.
2.3 Using a Phillips-head screwdriver,
remove the four screws that secure the
power stand base plate to the bottom of the
line array cavity. Lift it off of the cavity. Be
careful not to damage any wires.
2.4 Once all of the wiring is disconnected,
use a Phillips-head screwdriver to remove
the 16 screws that secure the amplifier
housing to the power stand upper housing.
Carefully lift the amplifier housing out of the
power stand upper housing.
3. Line Array Cavity Removal
3.1 Perform procedure 2.
3.2 Using a Phillips-head screwdriver,
remove the three screws that secure the line
array cavity to the upper housing. Lift the line
array cavity off of the upper housing. The
power stand foot pedal will disengage from
the shaft.
71
Disassembly Procedures
4. Amplifier PCB Removal
4.1 Perform procedure 2.
4.2 Make a note of the wiring and disconnect
all of the wiring harnesses that connect the
power supply box to the DSP PCB and to the
microprocessor PCB.
4.3 Using a Phillips-head screwdriver,
remove the 24 screws that secure the power
supply box top cover in place. Lift off the top
cover.
4.4 Once you have the top cover off, make a
note of the wiring configuration and unplug
the wiring harnesses that connect to the
amplifier PCB.
4.5 Using a Phillips-head screwdriver,
remove the 6 screws that secure the amplifier PCB in place. Lift the amplifier PCB out
of the chassis.
5. +/-27VDC SMPS Removal
5.1 Perform procedure 2.
5.2 Make a note of the wiring and disconnect
all of the wiring harnesses that connect the
power supply box to the DSP PCB and to the
microprocessor PCB.
5.3 Using a Phillips-head screwdriver,
remove the 24 screws that secure the power
supply box top cover in place. Lift off the top
cover.
5.4 Once you have the top cover off, make a
note of the wiring configuration and unplug
the wiring harnesses that connect to the
switching DC power supply PCB you wish to
remove.
5.5 Using a Phillips-head screwdriver,
remove the 4 screws that secure power
supply PCB in place. Lift the power supply
PCB out of the chassis.
72
Disassembly Procedures
6. Auxiliary Power Supply Removal
6.1 Perform procedure 2.
6.2 Make a note of the wiring and disconnect
all of the wiring harnesses that connect the
power supply box to the DSP PCB and to the
microprocessor PCB.
6.3 Using a Phillips-head screwdriver,
remove the 24 screws that secure the power
supply box top cover in place. Lift off the top
cover.
6.4 Once you have the top cover off, make a
note of the wiring configuration and unplug
the wiring harnesses that connect to the
switching DC power supply PCB you wish to
remove.
6.5 Using a Phillips-head screwdriver,
remove the 4 screws that secure the power
supply PCB in place. Lift the power supply
PCB out of the chassis.
7. EMI (FCC) Filter PCB Removal
7.1 Perform procedure 2.
7.2 Make a note of the wiring and disconnect
all of the wiring harnesses that connect the
power supply box to the DSP PCB and to the
microprocessor PCB.
7.3 Using a Phillips-head screwdriver,
remove the 24 screws that secure the power
supply box top cover in place. Lift off the top
cover.
7.4 Once you have the top cover off, make a
note of the wiring configuration and unplug
the wiring harnesses that connect to the EMI
Filter PCB.
7.5 Using a Phillips-head screwdriver,
remove the 4 screws that secure the EMI
Filter PCB in place. Lift the EMI Filter PCB
out of the chassis.
73
Disassembly Procedures
8. Chassis Fan Removal
8.1 Perform procedure 2.
8.2 Using a Phillips-head screwdriver,
remove the 24 screws that secure the power
supply box top cover in place. Lift off the top
cover.
8.3 Using a Phillips-head screwdriver,
remove the 4 screws that secure the fan to
the chassis.
8.4 Follow the wire harness for the fan you
are removing to the auxiliary power supply
PCB and unplug it. Lift the fan out of the
chassis.
Re-assembly note: When installing the new
fan, be sure to match the orientation of the
fan next to it so that it will move air in the
proper direction when in use.
9. Microprocessor PCB Removal
9.1 Perform procedure 1.
9.2 Make a note of the wiring configuration
and unplug the six wire harnesses from the
connectors on the board.
9.3 Lift the microprocessor PCB off of the
connectors that engage it on the bottom of
the board and the pins that connect to the
preset switches.
Re-assembly note: When re-installing this
PCB, be sure that all of the pins from the
preset switches are straight and properly
engage the connectors on the bottom of the
microprocessor PCB.
74
Disassembly Procedures
10. DSP PCB Removal
10.1 Perform proce-
dure 1.
10.2 Make a note of
the wiring configuration
and unplug the six wire
harnesses from the
connectors on the
board.
10.3 Using a pair of
needle-nose pliers, compress the bottoms of the plastic standoff posts used to attach the DSP
PCB to the Input/Output PCB. Lift the DSP PCB off of the I/O PCB.
11. Input/Output PCB Removal
11.1 Perform procedures 9 and 10.
11.2 On the front panel of the power stand, remove the four knobs for the mic trim and level
controls.
11.3 Using a nut driver, remove the nuts and washers for the 1/4 inch phono jacks.
11.4 Using a Phillips-head screwdriver, remove the screws that secure the XLR, Data in/out
and Neutrik connectors to the front panel.
11.5 Lift the I/O PCB off of the input panel.
75
Disassembly Procedures
Line Array Procedures
Note: The line arrays are divided into a
lower line array, which plugs directly into the
power stand, and an upper line array, which
uses a bayonet arrangement to align the
upper array to the lower array for connection. All electrical connections are automatically made when the arrays are mounted
into the power stand and the upper array is
mounted to the lower array.
Note: Refer to Figure 8 for the following
procedures.
1. Grille Removal
1.1 Using a Phillips-head screwdriver,
remove the six screws that secure the end
cap to the line array enclosure. Lift off the
end cap. Unplug the molex connector from
the speaker harness.
1.2 Grasp the edge of the grille and gently
lift it away from the enclosure.
2. Nameplate Removal
2.1 Perform procedure 1.
2.2 On the back of the grille, unbend the
legs of the logo. Lift off the nameplate.
4. Upper Line Array Top End Cap Removal
4.1 Using a Phillips-head screwdriver,
remove the seven screws that secure the
end cap to the line array enclosure. Lift off
the end cap.
Re-assembly note: Make sure that the end
cap gasket is properly aligned to achieve an
airtight seal.
5. Upper Line Array Bottom End Cap
Removal
5.1 Using a Phillips-head screwdriver,
remove the seven screws that secure the
end cap to the line array enclosure. Lift the
end cap away from the enclosure. Unplug
the molex connector from the speaker
harness.
Re-assembly note: Make sure that the end
cap gasket is properly aligned to achieve an
airtight seal.
6. Lower Line Array Top End Cap Removal
6.1 Using a Phillips-head screwdriver,
remove the six screws that secure the end
cap to the line array enclosure. Lift off the
end cap. Unplug the molex connector from
the speaker harness.
3. Driver Removal
3.1 Perform procedure 1.
3.2 Using a Phillips-head screwdriver,
remove the four screws that secure the
driver to the enclosure.
3.3 Lift the driver out of the enclosure. Note
the wiring configuration and cut the wires as
close to the driver terminals as possible.
Re-assembly note: Make sure that the end
cap gasket is properly aligned to achieve an
airtight seal.
7. Lower Line Array Bottom End Cap
Removal
7.1 Using a Phillips-head screwdriver,
remove the seven screws that secure the
end cap to the line array enclosure. Lift the
end cap away from the enclosure. Unplug
the molex connector from the speaker
harness.
Re-assembly note: Make sure that the end
cap gasket is properly aligned to achieve an
airtight seal.
76
Disassembly Procedures
8. Front Cap Removal
8.1 Using a Phillips-head screwdriver,
remove the four screws that secure the front
cap to the bottom front of the line array
enclosure. Lift the end cap away from the
enclosure.
Bass Module Procedures
Note: Refer to Figure 9 for the following
procedures.
1. Grille Removal
1.1 Using an allen wrench, remove
the four screws that secure the grille to the
upper and lower speaker end caps.
1.2 Lift off the grille.
2. Nameplate Removal
4. Input Panel Removal
4.1 Using a Phillips-head screwdriver,
remove the four screws that secure the
input panel to the bass module enclosure.
4.2 Lift the input panel away from the bass
module enclosure.
4.3 Make a note of the wiring configuration
and un-solder the speaker harness wires
from the input panel.
2.1 Perform procedure 1.
2.2 On the back of the grille, remove the
retaining nut and spring from the post of the
nameplate. Lift the nameplate off of the
grille.
3. Driver Removal
3.1 Perform procedure 1.
3.2 Using a Phillips-head screwdriver,
remove the four screws that secure the
driver to the bass module enclosure.
3.3 Lift the driver out of the enclosure. Note
the wiring configuration and cut the wires as
close to the driver terminals as possible.
Re-assembly notes:
- When soldering the speaker harness wires
to the new driver, be sure to observe polarity
of the driver harness wires.
- Be sure to properly align the gasket behind
the new driver to ensure an airtight fit.
77
2-Mar-2007
S-DATA Out
(to SPDIF)
Ch 3 In
Ch 4 In
L
R
Master Vol. Range: -80 to +22dB (+10@12:00)
Sys. EQ+X-Over, Hi
Sys. EQ+X-Over, LoLimiter
Limiter
Knee=+1.5dBV
Bass Out
Hi Out
Remote
Figure 11. L1
+24v
O
PHANTOM
Ch2 In
Ch1 In
DSP Processing Block Diag
-1
User EQPreset EQNoiseGate
User EQPreset EQNoiseGate
3
Ch1/2 Preset
Remote
®
Model I Power Stand Block Diagram
Max. Level = +10dBV
Nom. Level = -21dBV(Trim ctr)
Min. Level = -66dBV for full output
Input-LINE
PHANTOM
Control
Ch2 Insert
0dB
Nom. -10dBV
Clip@+6dBV
Data In
(SPDIF)
(Trim, Ch1 Vol+Master @ Max)
Input-MIC
O
+24v
+24
Clip@+18dBV
Volume
Digital
2-Ch.
Max. Gain = 0dB
Nom. Gain = -10dB (12:00)
Min. Gain = -40dB
+1
+1
0dB
+1
+1
0dB
0dB
12
3
INA163
5K 10C
Nom.: 0dBV
TC A9459F
Tip = Return
Nom. -10dBV
Clip@+6dBV
+24
Input-MIC
3
INA163
Ch2 Line Out
+1
12
Clip@+24dBV
Ch2
12
+8 to +50 dB
Mic (XLR) input
+21dB @ ctr
5K 10C
Trim
Nom.: +6dBV (Balanced)
Ring = Send
Tip = Return
-20dB
Line (1/4") input
Sig/OL
(SPDIF)
+1
-12 to +30 dB
+1dB @ ctr
Data-Out
CS5361
Xmiter
S3PC8475
SPDIF
Rcvr
SPDIF
A/D
A/D
CS8416
CS8406
µC
DSP
Ch1
+8 to +50 dB
Mic (XLR) input
+21dB @ ctr
Ring = Send
A/D
A/D
+1
-20dB
-12 to +30 dB
Line (1/4") input
+1dB @ ctr
Sig/OL
Trim
Green=Signal= -30dBV
Red=Clip=+6dBV
-1
3
Ch1 Insert
Nom. -10dBV
Clip@+6dBV
CS5361
ADS21065L
Max. Level = +18dBV [input buer clips]
Nom. Level = -1dBV
Min. Level = -46dBV for full output
Input-LINE
(Ch1 Vol+Master @ Max)
Ch1 Line Out
+1
BLOCK DIAGRAM -
12
Nom.: +6dBV (Balanced)
Clip@+24dBV "
Signal Processing + Routing
Master
Level
Low
Sig/OLSig/OL
Clip= -4dBV into A/D
Signal= -40dBV into A/D
Persistence = 100msec
BASS SPEAKER SENSING:
R=Open: Amp1&2 Wider-Band EQ
R=10K: 40-150Hz X-Over on Bass,
>150Hz-Hi
R=5K: X-Over on Bass Ch, -6dB Hi Range
Mid
Ch1 Ch2
High
250W@4 Ohms
+1dBV (1.1V) for
8/4 ohm Sense
2+
+29dB
+5
1-
2-
8/4 ohm Sense
Ch1Ch2
PRESET
Power
Amp
Clip @ +30dBV
1+
(250W 4ohms)
0 1
0 1
Amp2
Bass Module
Bass Slave Sense
Amp
+29dB
Power / Protect / Diagnostic
Master Vol Ctrl
+5
5
678
9
Amp1
Power
LineSource
Top+Bottom
432
Bass Send
D/A
LPF
1
-1+1
-1.5dB
D/A
LPF
CS4392
-1.5dB
+20dB
+2.6dB @ 12:00
Level
20K 15A
Ch 4 IN
Ch 3 IN
Max. Level = +40dBV+
Nom. Level = -13dBV (pot @ ctr)
Min. Level = -30dBV for full output
+20dB
Level
20K 15A
Rev:
A
78
Test Procedures
L1® Model I Power Stand Tests
Equipment Required
•dB Meter
•Digital Multi-meter
•Audio Signal Generator
•Distortion Meter
•2 - 4 Ohm, 250 Watt Load Resistors
•Test cables, see Appendix
Overall System Tests
Notes:
1. Do not connect the R1 remote control for
the following tests, unless specified. Powering up the power stand without the remote
has the same effect as setting all of the
controls on the remote to the midpoint.
2. On the front panel of the power stand, set
the Channel 1 and Channel 2 Preset Select
switches to 00. Short out the 2+ and 2connections on the B1 Bass Module output
connector using the test cable described in
section 1 of the appendix of this manual.
This will put the power stand into debug
mode for the following tests. In this mode the
crossover, the compressor and the EQ are
disabled. The DSP will pass a flat response.
The level controls and the clip indicators still
operate in this mode.
3. Refer to Figure 11, L1 Model I Block
Diagram, for the following procedures.
1. Channel 1 and 2 Mic Input Gain Tests
1.3 Using a balanced XLR male input cable,
apply a 1 kHz, -30dBV signal to the channel
1 input.
1.4 Reference a dB meter to the input level.
Measure the gain at the output of the
powerstand boot cable described above.
It should be +48.5 dB + 3 dB.
1.5 Repeat steps 1.1 to 1.4 for the channel
2 Mic input.
2. Channel 1 and 2 Mic Input Frequency
Response and Distortion Tests
2.1 Connect the powerstand boot test cable
to where the line array would usually sit.
Details on this cable appear in the appendix.
2.2 On the left hand side of the input/output
panel, set the channel 1 Mic Trim control to
the 6 setting. Ensure that the phantom
power push button is not pushed in.
2.3 Using a balanced XLR male input cable,
apply a 1 kHz, -30 dBV signal to the channel
1 input.
2.4 Use an 80kHz low-pass filter on your
measuring equipment. Reference a dB
meter to the input level. Measure the frequency response at the powerstand boot
test cable. It should be 0 dB + 3 dB from
30 Hz to 15 kHz.
1.1 Connect the powerstand boot test cable
to where the line array would usually sit.
Details on this cable appear in the appendix.
1.2 On the left hand side of the input/output
panel, set the channel 1 Mic Trim control to
the 6 setting. Ensure that the Phantom
Power push button is not pushed in.
2.5 Measure the total harmonic distortion
(THD) level at the powerstand boot cable.
It should be 0.25% max at 1 kHz and 1.5%
max at 15 kHz.
2.6 Repeat steps 2.1 to 2.5 for the channel
2 Mic input.
79
Test Procedures
3. Channel 1 and 2 Mic Input Signal to
Noise Ratio (Dynamic Range) Tests
3.1 Connect the powerstand boot test cable
to where the line array would usually sit.
Details on this cable appear in the appendix.
3.2 On the left hand side of the input/output
panel, set the channel 1 mic trim control to
the 6 setting. Ensure that the phantom
power push button is not pushed in.
3.3 Using a balanced XLR male input cable,
apply a 1 kHz, -30 dBV signal to the channel
1 input.
3.4 Reference a dB meter to the output level
at the powerstand boot cable. Remove the
input signal and measure the A-Weighted
output level. It should be -80 dB minimum.
3.5 Repeat steps 3.1 to 3.4 for the channel 2
Mic input.
4. Channel 1 and 2 Mic Input Phantom
Power Test
4.1 Plug an XLR connector into the channel
1 Mic input. Do not connect any cables to
the channel 1 or channel 2 Mic inputs.
Power on the unit.
4.2 Press the channel 1 phantom power
switch. Verify that the LED lights. Measure
the DC voltage level across pins 1 and 2 of
the XLR connector. Verify that the DC level
is +24Vdc + 1Vdc relative to pin 1.
4.3 Measure the DC voltage level across
pins 1 and 3 of the XLR connector. Verify
that the DC level is +24Vdc + 1Vdc relative
to pin 1.
5. Channel 1 and 2 Line Input Gain Tests
5.1 Connect the powerstand boot test cable
to where the line array would usually sit.
Details on this connector appear in the
appendix.
5.2 On the left hand side of the input/output
panel, set the channel 1 mic trim control to
the 6 setting. Ensure that the phantom
power push button is not pushed in.
5.3 Using an unbalanced 1/4" phono jack
input cable, apply a 1 kHz, -10 dBV signal
to the channel 1 input.
5.4 Reference a dB meter to the input level.
Measure the gain output at the powerstand
boot connector. It should be +28.5 dB + 4
dB.
5.5 On the signal generator, turn the input
level all the way down. Verify that the channel 1 Signal/OL LED is off. Increase the
signal generator level. Verify that the LED
lights green. Increase the signal level again
and verify that the LED lights red.
Note: You may have to increase the Mic
Trim level on the PS1 channel 1 input as
well to get the LED to light red.
5.5 Repeat steps 5.1 to 5.5 for the channel 2
Line input.
6. Channel 1 and 2 Line Input Frequency
Reponse and Distortion Tests
6.1 Connect the powerstand boot test cable
to where the line array would usually sit.
Details on this connector appear in the
appendix.
4.4 Repeat steps 4.1 to 4.3 for channel 2.
6.2 On the left hand side of the input/output
panel, set the channel 1 Mic Trim control to
the 6 setting. Ensure that the Phantom
Power push button is not pushed in.
6.3 Using an unbalanced 1/4" phono jack
input cable, apply a 1 kHz, -10 dBV signal
to the channel 1 input.
80
Test Procedures
6.4 Use an 80 kHz low-pass filter on your
measuring equipment. Reference a dB
meter to the input level. Measure the frequency response at the powerstand boot
connector. It should be 0 dB + 3 dB from
30 Hz to 15 kHz.
6.5 Measure the Total Harmonic Distortion
(THD) level at the powerstand boot connector. It should be 0.25% max at 1 kHz and
1.5% max at 15 kHz.
6.6 Repeat steps 6.1 to 6.5 for the channel 2
Line input.
7. Channel 1 and 2 Line Input Signal to
Noise Ratio (Dynamic Range) Tests
7.1 Connect the powerstand boot test con-
nector to where the line array would usually
sit. Details on this connector appear in the
appendix.
8.3 Reference a dB meter to the input level.
Measure the gain output at the Bass/Amp 3
OUT jack. It should be +40.1 dB + 3 dB.
8.4 Repeat steps 8.1 to 8.3 for the channel
4 Line input.
9. Channel 3 and 4 Line Input Frequency
Response and Distortion Tests
9.1 Connect the powerstand boot test con-
nector to where the line array would usually
sit. Details on this connector appear in the
appendix.
9.2 On the left hand side of the input/output
panel, set the channel 4 trim control to the
6 setting.
9.3 Using an unbalanced 1/4" phono jack
input cable, apply a 1 kHz, -20 dBV signal
to the channel 1 input.
7.2 On the left hand side of the input/output
panel, set the channel 1 Mic Trim control to
the 6 setting. Ensure that the Phantom
Power push button is not pushed in.
7.3 Using an unbalanced 1/4" phono jack
input cable, apply a 1 kHz, -10 dBV signal to
the channel 1 input.
7.4 Reference a dB meter to the output level
at the powerstand boot connector. Remove
the input signal and measure the AWeighted output level. It should be -80 dB
minimum.
7.5 Repeat steps 7.1 to 7.4 for the channel 2
Line input.
8. Channel 3 and 4 Line Input Gain Tests
8.1 On the left hand side of the input/output
panel, set the channel 3 Level control to the
6 setting.
8.2 Using an unbalanced 1/4" phono jack
input cable, apply a 1 kHz, -20 dBV signal to
the channel 1 input.
9.4 Use an 80 kHz low-pass filter on your
measuring equipment. Reference a dB
meter to the input level. Measure the frequency response at the powerstand boot
connector. It should be 0 dB + 3 dB from
30 Hz to 15 kHz.
9.5 Measure the Total Harmonic Distortion
(THD) level at the powerstand boot connector. It should be 0.25% max at 1 kHz and
1.5% max at 15 kHz.
9.6 Repeat steps 9.1 to 9.5 for the channel
4 Line input.
10. Channel 3 and 4 Line Input Signal to
Noise Ratio (Dynamic Range) Tests
10.1 On the left hand side of the input/
output panel, set the channel 3 Level
control to the 6 setting.
10.2 Using an unbalanced 1/4" phono jack
input cable, apply a 1 kHz, -10 dBV signal to
the channel 1 input.
81
Test Procedures
10.3 Reference a dB meter to the output
level at the Bass/Amp 3 OUT jack. Remove
the input signal and measure the AWeighted output level. It should be -80 dB
minimum.
10.4 Repeat steps 10.1 to 10.3 for the
channel 4 Line input.
11. Channel 1 and 2 Remote Control,
Preset Switch and Insert Function Tests
11.1 Connect the power stand to a known
good L1 model I line array. Set the channel 1
preset switch to 00. Connect the remote
control to the unit using the remote control
MIDI cable supplied with the power stand.
11.2 Connect an analog audio source to the
Channel 1 line input 1/4 inch jack. This
source can be a CD player with a music
disc.
11.3 Adjust the trim level so that the LED is
lit mostly green. The audio should sound
normal.
11.4 With the audio playing, change the
channel 1 preset to 97 and back to 00. The
channel should mute gracefully when the
preset switch is operated. The audio should
fade back in again about a second after the
switch has stopped operating.
Note: Preset 97 is a 1 kHz band pass
(telephone-type sound). Preset 00 should
sound normal.
11.5 Operate all channel 1 controls on the
remote (high, mid, low, volume and master
volume). All tone controls should have a
clearly audible effect and operate smoothly.
Channel volume may display a little “zipper”
noise, which is normal.
Note: Channel volume all the way down
does not mute the channel, but the output
level should be very low. There is a small,
but noticeable time delay between operating
the control and the audible effect. This is
normal. The master volume control should
operate smoothly without any artifacts.
11.6 Insert a 1/4 inch phono jack all the way
into the channel 1 Insert jack. The audio
should sound normal.
11.7 Insert a 1/4 inch phono jack into the
channel 3 Line IN jack and operate the
volume control on the power stand. The
audio should sound normal.
11.8 Repeat steps 11.1 to 11.7 for the channel 2 input.
12. Channel 1 Send, Line Output and
Digital Output Tests
Note: For these tests you will need an
external device that can accept both 1/4
inch and XLR inputs. A small mixer, such
as a Mackie or Behringer with headphones
connected works well for this. The master
volume control on the remote control should
be set all the way down to mute all sound
coming from the unit under test.
12.1 Connect the power stand to a known
good L1 model I line array. Set the channel
1 preset switch to 00. Connect the remote
control to the unit using the remote control
MIDI cable supplied with the power stand.
12.2 Connect an analog audio source to the
Channel 1 Line IN 1/4 inch jack. This source
can be a CD player with a music disc.
12.3 Adjust the trim level so that the LED is
lit mostly green. The audio should sound
normal.
12.4 Insert a 1/4 inch plug halfway into the
channel 1 Insert jack. The audio should
sound normal.
12.5 Connect the power stand channel 1
XLR Line OUT jack to the XLR input of the
mixer. The audio should sound normal.
Note: The power stand puts out a “professional” +4dBu level. You may have to turn
the the input trim control on the mixer all the
way down to prevent overloading the signal
and distorting it.
82
Test Procedures
12.6 Connect the Data Out jack of the PS1 to
a device that accepts a 48 kHz S/PDIF data
stream. The audio should sound normal.
13. Power Amplifier Tests
13.1 Connect the power stand to a known
good L1 model I line array. Set the channel 1
preset switch to 00. Connect the remote
control to the unit using the remote control
MIDI cable supplied with the PS1.
13.2 Connect an analog audio source to the
Channel 3 IN 1/4 inch phono jack. This
source can be a CD player with a music
disc.
13.3 Verify that audio comes from the L1
model I line array. The audio should sound
clean and undistorted.
13.4 Verify that audio comes from the B1
bass module. The bass should be clean and
undistorted.
15. Bass Module Auto-EQ Test
15.1 Connect a L1 line array to the power
stand. Connect an R1 remote control to the
power stand. Connect a B1 bass module to
the B1 Bass Module output jack on the
power stand. Connect an audio source to
the channel 1 and 2 inputs of the power
stand.
15.2 Set the channel 1 and 2 level controls
to identical settings so that both LEDs are
mainly green.
15.3 While the audio is playing, disconnect
the B1 bass module from the power stand.
The system should mute and un-mute and
audio should resume. The audio should
sound normal, but not punchy (no deep
bass).
15.4 Plug a dummy 1/4 inch phono jack into
the Bass Line Out jack. The system should
mute and un-mute again, but the audio
should sound thinner than before.
14. High SPL System Sweep Test
CAUTION: This test will be extremely loud.
Hearing protection is advised.
14.1 Connect a R1 remote control to the
power stand under test. Set the channel 1
controls to mid-level. Set the master volume
control on the remote to the 1 o’clock position. Set the channel 1 Mic Trim control on
the PS1 to 6. Connect a L1 model I line
array to the PS1. Connect a B1 bass module
to the PS1.
14.2 Connect a signal generator to the
channel 1 input on the PS1. Adjust the
signal generator and/or trim control so that
the Signal/OL LED is just below red.
14.3 Sweep the input frequency from 40 Hz
to 14 kHz. Listen for any unusual noises and
excessive distortion or drop-outs.
15.5 Remove the dummy plug. The system
should mute and un-mute and the audio
should sound normal again.
15.6 Re-connect the B1 bass module to the
power stand. The audio should mute and unmute again and sound normal.
15.7 Connect a second B1 bass module to
the first one. The audio should mute and unmute. The audio will sound very similar to
having only one bass module attached.
Disconnect the second bass module. The
system should mute and un-mute and the
audio should sound normal again.
83
Test Procedures
L1® Model I Line Array Tests
Set up the unit under test as shown below.
Upper or Lower
L1 Line Array
Audio Signal
Generator
Power Amplifier
INPUTOUTPUT
Upper or Lower L1
Line Array Test Cable
Note: To distinguish between normal suspension noise and rubs or ticks, displace the
cone slightly with your fingers. If the noise
stays the same, it is normal suspension
noise and the driver is good. Suspension
noise will not be heard with program material.
3. Transducer Phase Test
3.1 Apply a DC voltage of 10V, positive
applied to the positive tab of the dual
banana jack on the line array test cable and
negative applied to negative (gnd) tab.
3.2 All of the driver cones should move
outward when the DC voltage is applied.
3.3 Rewire any incorrectly connected transducers.
4. L1 Model I Line Array Sweep Test
1. Air Leak Test
1.1 Apply a 100 Hz, 10 Vrms sine wave to
the unit under test.
1.2 Listen carefully for air leaks from around
the end cap, the transducers and the grille.
Air leaks will be heard as a hissing or sputtering sound. All repairs must be hidden.
Test duration should be 5 seconds minimum.
2. Transducer Rub and Tick Test
2.1 Remove the transducer you wish to test
using the disassembly procedures in this
manual. Do not unplug the wires at the
transducer assembly terminals.
2.2 Connect a signal generator directly to
the terminals of the transducer assembly
under test.
4.1 Set up the upper or lower line array
section as shown in the figure on the previous page.
4.2 Apply a 100 Hz, 10 Vrms sine wave to
the input.
4.3 While listening to the output of the
system, sweep the input frequency slowly
from 100 Hz to 15 kHz.
4.4 Listen carefully for any extraneous
noises such as buzzing and ticking.
2.3 Apply a 20 Hz, 5 Vrms signal to the
transducer assembly.
2.4 Listen carefully for any extraneous
noises such as rubbing, scraping or ticking.
84
Test Procedures
B1 Bass Module Tests
Set up the unit under test as shown below.
Audio Signal
Generator
B1 Bass Module
Power Amplifier
INPUTOUTPUT
B1 Bass Module
Test Cable
1. Air Leak Test
1.1 Apply a 100 Hz, 20 Vrms sine wave to
the unit under test.
1.2 Listen carefully for air leaks from around
the end cap, the transducers and the grille.
Air leaks will be heard as a hissing or sputtering sound. All repairs must be hidden.
Test duration should be 5 seconds minimum.
3. Transducer Phase Test
3.1 Apply a DC voltage of 20V, positive
applied to the positive tab of the dual
banana jack on the bass module test cable
and negative applied to negative (gnd) tab.
3.2 Notice carefully that all driver cones
should move outward when the DC voltage
is applied.
3.3 Rewire any incorrectly connected transducers.
4. System Sweep Test
4.1 Set up the system as shown in the
figure at left.
4.2 Apply a 10 Hz, 20 Vrms sine wave to the
input.
4.3 While listening to the output of the
system, sweep the input frequency slowly
from 10 Hz to 400 Hz.
2. Transducer Rub and Tick Test
2.1 Remove the transducer you wish to test
using the disassembly procedures in this
manual. Do not unplug the wires at the
transducer assembly terminals.
2.2 Connect a signal generator directly to
the terminals of the transducer assembly
under test.
2.3 Apply a 10 Hz, 10 Vrms signal to the
transducer assembly.
2.4 Listen carefully for any extraneous
noises such as rubbing, scraping or ticking.
Note: To distinguish between normal suspension noise and rubs or ticks, displace the
cone slightly with your fingers. If the noise
stays the same, it is normal suspension
noise and the driver is good. Suspension
noise will not be heard with program material.
4.4 Listen carefully for any extraneous
noises such as buzzing and ticking.
85
Appendix
L1® Model I Power Stand Test Cables
Note: In order to be able to properly test the L1 Model I Power Stand, you will need to make a
This cable is used to connect the B1 Bass Module output jack to the load resistors used in the
test procedures. The connector used is a Neutrik NL4FX Speakon X-Line / 4 Pole type. This
connector has 4 terminals labeled 1+, 1-, 2+ and 2-. Terminals 1+ and 1- are used to connect to
the load resistors. Use 18 or 16 AWG wire for these terminals. Use twisted pair wires to avoid
inducing noise into the cable during use.
The 2+ and 2- terminals will be used to sense the loads connected to the Speakon connector
when used with the B1 Bass Module jack. This jack automatically senses the load on this jack to
properly tailor the EQ and output level for the connection of one or two bass modules. It does
this by sensing the resistive value across terminals 2+ and 2-. The bass modules have a 10k
ohm resistor across these terminals. When only one bass module is connected, the power
stand sees the 10k resistance and sets the EQ and output level accordingly. When two bass
modules are connected, it sees 5k and sets the EQ and output level accordingly. For the test
cable, you will use 18 AWG twisted pair wire to a dual banana jack.
It is also useful to have 3 spare banana jacks, one with a short across it and 2 with a 10k Ohm,
1/4 Watt resistor each to simulate a bass module connected to the terminals.
GND
Amplifier output
to load resistor
16-18AWG twisted pair wire
1+1-
Neutrik Speakon
4 pole connector
(back shown)
2-2+
18AWG twisted pair wire
Dual banana jack
Dual banana jack
GND
Bass module
sensing output
Figure 12. Amplifier Output Test Cable Wiring Diagram
86
Appendix
TIP RINGSLEEVE
2. Powerstand Boot Test Cable
1 - 10 pin Molex female connector, Molex part number 39-01-3103
4 - Molex crimp-on pins for above connector
1 - dual banana jack
12 feet of 16 or 18AWG twisted pair wire
Cut the 12 foot length of twisted pair wire in half. Strip all of the wires back about 1/4 inch.
Crimp the molex pins onto the wires. The positive (+) side of the twisted pair wires will go into
pins 3 and 8 of the Molex connector. The negative (-) side of the twisted pair wires will go into
pins 4 and 9 of the Molex connector. Connect the wires that go to pins 3 and 8 of the Molex
connector to the positive (+) side of the dual banana jack. Connect the wires that go to pins 4
and 9 of the Molex connector to the negative (-) side of the dual banana jack.
This test cable plugs into the boot connector of the L1TM Model I Power Stand for all line array
amplifier tests.
3. XLR Microphone Input Test Cable
Parts needed:
1 - XLR male connector
1 - Dual banana jack
18 AWG shielded twisted pair wire, 6 feet
This cable is used to test the channel 1 and 2 microphone inputs on the power stand. These
input jacks are dual purpose jacks that will accept either XLR or 1/4" TRS phono jack balanced
inputs.
Connect the dual banana jack’s positive (+) connection to pin 2 of the XLR jack. Connect the
dual banana jack negative (-) connection to pin 3 of the XLR jack. Connect the cable shield to
pin 1 of the XLR jack.
4. Line Input 1/4" Phono Jack Test Cable
Parts needed:
1 - Mono 1/4" phono jack
1 - Dual banana jack
18 AWG shielded twisted pair wire, 6 feet
This cable is used to test the channel 1 and
2 line inputs on the power stand.
Connect the dual banana jack’s positive (+) connection to the tip connection of the 1/4" phono
jack. Connect the dual banana jack negative (-) connection to the ring connection of the 1/4"
phono jack.
87
Appendix
5. Insert Jack Test Cable
This cable is used to test the channel 1 and 2 insert jacks on the power stand. When you plug it
into the channel 1 or channel 2 insert jack, you will be able to separate the sections of the
electronics. Refer to the power stand block diagram on page 71. The RETURN dual banana
jack will give you the output of the circuitry up to the output of the 2 channel digital volume
control. The SEND dual banana jack will allow you to input a signal to test the circuitry after the
insert jack, which is the input to the A/D converter and DSP.
For each of the shielded stereo pairs of wires, connect the dual banana jack’s positive (+)
connection to the center conductor. Connect the dual banana jack’s negative (-) connection to
the shield wires. Use an Ohmmeter to determine which of the center conductors is connected to
the ring of the 1/4 inch TRS phono jack. Using a permanent black magic marker, label this dual
banana connector SEND. Determine which of the center conductors is connected to the tip of
the 1/4 inch TRS phono jack. Label this dual banana connector RETURN. The sleeve portion of
the jack is the common ground where the shields are connected.
6. L1® Model I Line Array Test Cables
These two cables will allow you to test the upper and lower line array sections without an L1
Model I power stand. Use these cables for the line array test procedures in this service manual.
Lower Line Array Section Test Cable
Parts needed:
1 - 10 pin Molex male connector, Molex part number 39-00-0039 (F)
4 - Molex crimp-on pins for above connector, Molex part number 39-00-0039
1 - dual banana jack
12 feet of 16 or 18AWG twisted pair wire
Cut the 12 foot length of twisted pair wire in half. Strip all of the
wires back about 1/4 inch. Crimp the molex pins onto the wires.
The positive (+) side of the twisted pair wires will go into pins 3
and 8 of the Molex connector. The negative (-) side of the twisted
pair wires will go into pins 4 and 9 of the Molex connector. Connect the wires that go to pins 3 and 8 of the Molex connector to
the positive (+) side of the dual banana jack. Connect the wires
that go to pins 4 and 9 of the Molex connector to the negative (-)
side of the dual banana jack.
12354
678910
Molex Connector Rear View
88
Appendix
Upper Line Array Section Test Cable
Parts needed:
1 - 4 pin Molex male connector, Molex part number 39-01-2041
4 - Molex crimp-on pins for above connector, Molex part number 39-00-0041 (M)
1 - dual banana jack
12 feet of 16 or 18AWG twisted pair wire
Cut the 12 foot length of twisted pair wire in half. Strip all of the wires back
about 1/4 inch. Crimp the molex pins onto the wires. The positive (+) side of
the twisted pair wires will go into pins 2 and 4 of the Molex connector. The
negative (-) side of the twisted pair wires will go into pins 1 and 3 of the
Molex connector. Connect the wires that go to pins 2 and 4 of the Molex
connector to the positive (+) side of the dual banana jack. Connect the wires
that go to pins 1 and 3 of the Molex connector to the negative (-) side of the
dual banana jack.
6. Bass Module Test Cable
Parts needed:
1 - Neutrik® Speakon® NL4FX connector
Bass Module Test Cable
1 - dual banana jack
6 feet of 16 or 18AWG twisted pair wire
16-18AWG twisted pair wire
Strip all of the wires back about 1/4 inch.
Connect the dual banana jack’s positive (+)
connection to the 1+ connection of the
Speakon connector. Connect the dual
banana jack negative (-) connection to the
1- connection of the Speakon connector.
1+1-
Neutrik Speakon
4 pole connector
(back shown)
2-2+
34
12
Molex Connector
Rear View
GND
Dual banana jack
89
Appendix
L1® Model I Power Stand Software Update Procedure
Required Equipment:
1- CD player with a S/PDIF digital output (do not use a Bose
1- L1 Model I Power Stand update CD (see the instructions for creating this disc below)
1- S/PDIF video cable, part number 183200, or an audio cable with RCA connectors
1- L1 Model I Power Stand AC line cord
L1 Model I Power Stand Update CD Procedure:
®
Lifestyle® media center)
• Go to the Bose Technical Service web page at http://intranet.bose.com/tsg (Bose internal
repair centers) or http:serviceops.bose.com (external Bose affiliated repair centers).
• Navigate to the L1 Model I web page. The link to it is located on the Pro Products web page.
• Scroll down the page until you see the table that the link to the L1 Model I Power Stand soft-
ware update is located in. Download the file to your computer’s desktop.
• Using a CD burner and your CD burner software, burn the file onto a blank CD-R or CD-RW
disc. Once this disc is successfully created, label the disc with the revision of the software.
Update Procedure:
• Plug the CD player into an AC mains outlet.
• Connect the S/PDIF cable to the Audio Outputs/Digital jack on the back of the CD player.
• Connect the other end of the S/PDIF cable to the DATA IN jack on the Power Stand’s input
panel. This jack is located in the middle of the panel. It’s an RCA jack with a white center.
• Connect the Power Stand’s AC line cord to the AC mains jack on the input panel. This jack is
located on the right side next to the power switch.
• Connect the other end of the AC line cord to an AC mains outlet.
• Power up the Power Stand by moving the power switch to the ON position. Wait for the
power LED to light steady green.
• Load the update CD into the CD player. Press the PLAY CD/DVD button on the remote
control. The update process should begin.
• Wait about 5 seconds while the disc is playing. The green power LED on the Power Stand
should blink rapidly, about 10 times per second. After about 10 seconds, the LED should begin
to blink slower, about twice a second.
• The update process is complete. Power down the Power Stand. Disconnect the S/PDIF
cable from the DATA IN jack.
• Verify proper operation of the Power Stand using the test procedures in this service
manual before returning the unit to the customer.
Troubleshooting:
Problems with this update procedure are indicated by the Power Stand’s power LED.
Typical indicators are:
• LED stays a steady green.
• LED blinks slowly red
In either case, simply repeat the process above. Make sure you wait 5 seconds after power
up of the Power Stand before playing the update disc. Ensure all of the cables are properly
connected.
90
Theory of Operation
®
1. L1
Model I Power Stand
1.1 Overview
The L1 Model I System is essentially a Natural Amplification sound system, with the following
components:
L1 Model I Power stand, two L1 Model I Cylindrical Radiator® line array sections, R1 remote
control, B1 bass module, AC power cord, remote control cable and bass module loudspeaker
cable (see below). Note: The B1 bass module is an optional component.
R1 remote
control
PS1 power stand
Remote
control cable
AC power cord
B1 bass module 4-wire cable (blue)
Upper and Lower L1 Cylindrical
Radiator™ loudspeaker
B1 bass module
L1 Model I System Components
Changes from the Personalized Amplification System
The L1 Model I power stand is essentially a RoHS compliant update of the Personalized
Amplifcation System. The unit remains functionally unchanged except for a few key points:
1. The line array is now powered by one 250W amplifier instead of two, as on the PAS power
stand. The two line array sections are now wired in parallel and powered by a single amplifier.
They are each 8 ohms, wired in parallel, for a total of 4 ohms in operation. Due to optimization
of the speaker to the amplifier, the output level is virtually the same as the Personalized Amplification System power stand. There is a mechanical stop in the power stand cavity to prevent
users from plugging a PAS line array into an L1 Model I power stand. Users can, however, insert
an L1 Model I line array into a PAS power stand. This will not harm the unit, but will result is a
few dB of loss in output.
2. All ‘Auxiliary’ speaker connectors on the power stand input panel have been removed.
These connectors were originally used intended for users to access the power stand amplifiers
in a stand-alone fashion. They were rarely used and were removed from the L1 Model I power
stand.
91
Theory of Operation
Features
The system has the following features:
•All signal processing performed with DSP
•Remote control
•The ability to receive analog signal input and SPDIF digital signal input
•The ability to output analog signal and SPDIF digital signal.
•Channel volume control
•Master volume control
•Mixer
•Tone control
•100 sets of parameter equalizer
•System equalizer for compensating speaker characteristic
•Noisegate
•Limiter
•Clip indicator
•DSP software update and 100 sets of preset coefficients update
•Power protection and amplification protection
The system delivers 250W of output power for each of the two amplifiers housed in the power
stand. The system uses a 110V / 230V AC power supply, and has a 1M ohm input impedance at
the audio Ch1/Ch2 line input connector and 1.25k ohm input impedance at the audio Ch1/Ch2
MIC connector. Input signal headroom is 2.1Vrms max. A user could operate the system from
the input panel and the remote (refer to figures below).
Power stand Input and Output Connections
92
Theory of Operation
0
0
HIGH
MID
LOW
LEVEL
MASTER
0 12
CH2
00
0
-12 +12
0
0 12
SIG / OLSIG / OL
CH1
-12 +12-12 +12
-12 +12
-12 +12-12 +12
0 12
R1 remote control
Note: Refer to L1® Model I power stand schematic sheets later in this service manual for the
following information. The information inside the brackets [ ] is the component’s grid location on
the schematic sheet.
The power stand combines the traditional functions of a mixer, digital controller (system EQ and
limiter), power amplifier and mechanical speaker stand. The power stand block diagram (figure
11 on page 71) shows the signal flow through the power stand.
The power stand contains eight PCB assemblies: an EMI (FCC) Filter PCB, two +/-27VDC
switching power supply PCBs, and Auxiliary Power Supply PCB, 2 channels of amplification on
a common PCB, an input panel PCB, DSP PCB, and MCU PCB.
Signal Routing
The power supply connects to the MCU PCB via a the 8 pin connector CN409 [microprocessor
PCB sheet 2, A1], four channels of analog inputs on the panel are connected to the DSP PCB
via a 6 pin connector CN104 [DSP PCB sheet 1, B1], analog output signals on the DSP panel
are connected to input panel via a 3 pin connector CN115 [input panel PCB sheet 2, D1]. SPDIF
IN on the input panel is connected to the DSP PCB via a 2 pin connector CN112 [DSP PCB
sheet 2, B4], SPDIF OUT on the DSP PCB is connected to input panel via a 2 pin connector
CN113 [DSP PCB sheet 2, C8].
For Channel 1 or 2 the signal is input either through the balanced XLR connector or through the
¼” unbalanced connector. The ¼” connector has a very high impedance (900k ohms) to allow
direct connection of passive guitars or bass guitars. The signal is then amplified by the adjustable pre-amplifier. After the pre-amplifier, the signal can be accessed at the balanced XLR line
level output.
Next the signal is routed through a digitally controlled analog volume control. Then, the signal is
routed through the insert loop connector. If there is no plug in the insert jack, the signal will be
routed through. Otherwise the signal will be routed to the “ring” of the connector and is expected
to return from the “tip”. The signal is then digitized in the A/D converters and processed in
software.
93
Theory of Operation
t
Software provides the following functions
•Channel 1&2: measuring level for LED
•Channel 1&2: noise gate
•Channel 1&2: preset EQ
•Channel 1&2: channel volume
•Sum channels 1 to 4
•Master Volume Control
•System EQ and crossover (for L1 and B1)
•Limiter & soft clipper (for L1 and B1 amplifiers)
Signal Processing
Signal processing is mainly implemented by the DSP and includes the following functions:
•Noisegate & limiter
•Tone control & volume control
•Parameter equalize & System equalizer
•Clip calculate
The signal flow chart is as follows (refer to the block diagram below):
Ch1 In
Ch2 In
S-DATA Out
(to SPDIF)
Ch 3 In
Ch 4 In
Remote
Ch1/2 Preset
DSP Processing Block Diag
User EQPreset EQNoiseGate
User EQPreset EQNoiseGate
L
R
Sys. EQ+X-Over, Hi
Sys. EQ+X-Over, LoLimiter
Master Vol. Range: -80 to +22dB (+10 @ 12:00)
DSP Functional Block Diagram
Limiter
Knee=+1.5dBV
Hi Out
Bass Ou
94
Theory of Operation
Power supplies
To ensure that the system operates normally, the system must be supplied with seven different
voltage levels, +3.3V, +5V, +15V, -15V, +24V, +27V, and -27V. Refer to the block diagram below.
DC Power Supply Block Diagram
110V AC is changed to about 300V DC, after passing through the EMI filter and the diode
bridge. Then, the voltage signal is divided two ways: one DC voltage goes through the switch
control & auxiliary circuit1 again, enters into the transformer primary1. The transformer1 has five
secondary windings, the first outputs +24V DC (for the input panel), the second outputs +15V
DC (for A/D, D/A buffer circuit), the third outputs –15V DC (for A/D, D/A buffer circuit), the fourth
outputs +5V DC (for MCU and other ICs), the fifth outputs +3.3V DC (for DSP, A/D & D/A IC).
Another DC voltage goes through the switch control & auxiliary circuit2 and enters into transformer primary2. The transformer1 has two secondary, the first outputs -27V DC (for AMP), the
second outputs +27V DC (for AMP).
Operation of the all voltage switching regulator is more complicated. The load of +3.3V is the
heaviest, so we get this +3.3V as feedback a signal and send it to the switch control & auxiliary
circuit1. When the system works, if +3.3V happens to waver, switch control & auxiliary circuit1
will change ‘open’ and ‘close’ time of switch circuit to regulate the transformer primary1, accordingly, the voltage of transformer1 secondary will keep stable. Of course, in this way, the effect of
stabilization for +3.3V is best, and that for other voltage is worse.
95
Theory of Operation
The regulation of the power supply for AMP is like this: we get the +27V as feedback signal and
send it to switch control & auxiliary circuit2. When system works, if +27V happens to waver,
switch control & auxiliary circuit2 will change ‘open’ and ‘close’ time of switch circuit to regulate
the transformer primary2, accordingly, the voltage of transformer2 secondary will keep stable.
When the system works, +5V can supply 100mA to MCU PCB, +3.3V can supply 260mA to DSP
PCB, +15V can supply 200mA to DSP PCB, -15V can supply 150mA to DSP PCB, and the
+24V can supply 50mA to the Input Panel PCB.
Microcontroller
A microcontroller on the MCU PCB is used for the following control functions:
•Relay DSP information to Remote
•Relay Remote information to DSP
•Control channel volume IC
•Check channel preset switch
•Check bass send state
•Check power & amplification protection
•Check the number of bass speakers connected to the power stand
•Indicate current system working status with a three color LED
These functions are explained in detail on the next page.
Relay DSP information to Remote
The DSP needs to transfer the clip state, channel volume data (cause the table for channel
volume in the DSP), and the system working status to the MCU. The communication adopts
software simulation UART, with two I/O pins as RX and TX. The communication rate is 4800bps,
add a start bit and stop, so every sending byte has 10 bits. Data is sent according to frame
format: frame head | every data | check sum. DSP will transfer a frame every 100ms, and every
sending will take about 15ms.
The MCU needs to transfer the clip state to the Remote. The communication adopts hardware
UART. Communication rate is 9600bps, Data is sent according to the MIDI protocol: MIDI
channel number | MIDI parameter type | MIDI parameter value. The DSP will transfer a frame
data every 100ms, and every sending will take about 3.5ms.
Relay Remote information to DSP
The remote needs to transfer the Ch1EQHi, Ch2EQHi, Ch1EQMi, Ch2EQMi, Ch1EQLo,
Ch2EQLo, Ch1Volume, Ch1Volume, and the MasterVolume to MCU. The communication
adopts hardware UART. Communication rate is 9600bps, Data is send according to MIDI protocol: MIDI channel number | MIDI parameter type | MIDI parameter value. DSP will transfer a
frame data every 100ms, and every sending will take about 30ms.
The MCU needs to transfer the Ch1EQHi, Ch2EQHi, Ch1EQMi, Ch2EQMi, Ch1EQLo,
Ch2EQLo, Ch1Volume, Ch1Volume, MasterVolume, Ch1Preset, Ch2Preset, BassChk, and the
CheckSum to the DSP. The communication adopts software simulation UART, with two I/O pin
as RX and TX. Communication rate is 4800bps, add start bit and stop, so every sending byte
has 10 bits. Data is send according to frame format: every data | check sum. DSP will transfer a
frame every 100ms, and every sending will take about 30ms.
96
Theory of Operation
Control channel volume IC
Because the design requires that the channel signal could change from –40dB to 0dB, we use a
volume control IC. There are three pins used to control the volume control IC: CLK, DATA, STB.
CLK, DATA and the STB time sequence is implemented by software.
Check channel preset switch
In the audio processing, there is a parameter equalizer, and the system supplies 100 sets of
coefficients for this function. A user could choose a different coefficient to get different sound
effects. This channel preset switch is a user interface to provide the function for choosing a
different coefficient.
Check bass send state
There is a bass-line out plug on the input panel. Through this plug, the system can connect to
one or more Bose® PackLite® Model A1 amplifiers to drive additional bass modules. The bass
send state only has two logic states “0” or “1”, indicating unconnected and connected. Different
states will choose different coefficients for the limiter and the system equalizer.
Check power & amplification protection
When the power supply and amplification have a problem, the system will indicate this to the
user by an LED on the input panel. The power & amplification protection signal also only has
two logic states “0” or “1”, indicating unprotected and protected.
Bass module sensing circuitry
On the bass connector, there are four pins. 1+ and 1- outputs bass signal, 2+ and 2- is used to
check the number of bass modules connected to the power stand. When there is no bass
module connected, the resistance value between 2+ and 2- is greater than 10k ohms, when one
bass module is connected to the power stand, the resistance between 2+ and 2- is equal to 10k
ohms, when two bass modules are connected, the resistance value between 2+ and 2- is equal
to 5k ohms, when there are more than two bass loudspeakers, the resistance value between 2+
and 2- is less than 5k ohms. Once the system detects how many, if any bass modules are
connected to the power stand, it will adjust the output level and the EQ accordingly to provide
the proper outputs for that configuration.
System Status LED
On the input panel PCB, there is a three color LED. The different colors of this LED represent
different operating conditions for the power stand.
•Green: operating normally
•Green blink fast: updating software or preset
•Green blink slowly: software update success
•Red blink slowly: software update failure
•Orange: power or amplification protection enabled (fault condition)
97
Theory of Operation
Codec
In the system, there are five codec ICs: U386 (for Ch1 & Ch2 A/D), U385 (for Ch3 & Ch4 A/D),
U387 (for line & bass D/A) [DSP PCB sheet 1, B/C/D5], U431 (for SPDIF IN) [DSP PCB sheet 2,
D3], U435 (for SPDIF OUT) [DSP PCB sheet 2, B6].
U386, U385, U387, U431, and U435 include the following functions:
•U386: Two channels of 24-bit ADC, one for Ch1 analog input and one for Ch2 analog input.
The ADC will input signal levels in levels in excess of 2Vrms. Master mode.
•U385: Two channels of 24-bit ADC, one for Ch1 analog input and one for Ch2 analog input.
The ADC will input signal levels in levels in excess of 2Vrms. Slave mode.
•U387: Two channels of 24-bit DAC, one for Line analog output and one for Bass analog
output. Maximum output signal level is 2Vrms. Slave mode.
•U431: Two channels of 24-bit digital audio interface receiver.8:2 S/PDIF Input MUX,
AES/SPDIF input pins selectable in hardware mode.
•U435: Two channels of 24-bit digital audio transmitter. Output Ch1/Ch2 input signal. Slave
mode.
•A crystal oscillator which establishes the ADC/DAC/SPDIF OUT sampling rate, in this case,
it is 12.288MHz / 256 = 48KHz.
•SPDIF IN sampling rate is the same as playing frequency, generally 44.1KHz.
•Word rate clock for the audio data on the SDOUT pin. Frequency will be the sample rate.
•Serial bit clock for audio data on the SDOUT pin.
•a serial bit stream containing the 24-bit audio data.
•U386, U385: 3-wire serial digital output port, U387: 3-wire serial digital input port,
•U431: 3-wire serial digital output port, U435: 3-wire serial digital input port. I
data output/input these ports.
In addition, the timing of the data flow into and out of the DSP is driven by the codec.
The serial ports on the DSP run asynchronously to the 30MHz clock which drives the
DSP.
2
S format digital
DSP
The DSP, U461 [DSP PCB sheet 3, B4] is an Analog Devices 21065L general purpose floating
point digital signal processor. There are two of these DSP ICs used in the system. Each is
capable of about 40MIPs of performance. The DSPs are mainly used to process sound effects.
They provide:
•Two channels noise gate
•Two channels tone control
•Two channels clip calculate
•Two channels parameter equalizer
•Four channels mixer
•Two channels system equalizer
•Two channels limiter
98
Theory of Operation
The DSPs have no internal ROM, at boot time they load themselves from the external FLASH
U462 [C7]. This boot process is more or less automatic, no intervention from the microcontroller
is required.
The signal required to connect the DSPs to the boot FLASH include:
•An external data address bus (24 bits, of which 18 are used)
•An external data bus (32 bits, of which 8 are used)
•Bus control signals
Finally the signals are brought out through a D/A stereo converter. The “left” channel contains
the signal for the L1, the “right” channel the signal for the bass module. The L1 signal is routed
to power amp 1 and the B1 signal to power amp 2.
Internally the outputs of power amp 1 is routed to a Molex connector in the base of the power
stand which connects to the L1 line array. The bass module is powered by power amp 2. The B1
signal is available as a balanced signal at the “Bass Line Out” TRS connector.
1.2 Gain Specifications
1.2.1 Purpose and Philosophy
The purpose of this specification is to define all relevant gain levels in the Bose
power stand and to specify procedures, for how these gains can be measured.
We’ll do this primarily by specifying a “nominal” level at each point. The “nominal” level repre-
sents the desired operating point. This is the level where we anticipate that the bulk of operation
occurs. Wherever warranted we will also do a headroom analysis in order to specify or derive
the maximum acceptable level before a stage clips or overloads.
The gain structure is designed in a way so that there is one point that handles the main system
constraint. This point is the digital limiter inside the DSP. If all levels are “nominal” the system
should just reach full output, the digital limiter should just be starting to work and all other
analog signals (except for the power amp, off course) should still have reasonable amounts of
headroom. This design allows controlling the high-signal behavior of the system completely in
software through the digital limiter and still offers good signal-to-noise properties.
1.2.2 Gains and Signal Levels
First, we need to define some reference levels for all the adjustable controls in the system. For
the “nominal” signal levels, we assume certain settings in those controls, and define the gain of
each adjustable section.
®
L1TM Model I
99
Theory of Operation
Control Gain Range Nominal Comment
TRIM –
Microphone
PreAmp
TRIM –Line
PreAmp
Ch1, Ch2
Volume
(Remote)
Master
Volume
(Remote)
Next we define all the nominal signal levels for full power output. All signal levels are specified in
dBV unbalanced unless otherwise noted. All levels in front of the DSP can be measured as such
directly. The post-DSP peak output levels can only be observed when the limiter is switched off.
Point Nominal Peak Comment
Line In, Trim @
Max
Line In, Trim @
12:00
Line In, Trim @
min
Mic., Trim @
max
Mic., Trim @
12:00
Mic., Trim @
min
Ch1, Ch2 Line
out XLR
Dig. Vol.
Control, input
Dig. Vol.
Control, output
Insert Send -10 dBV +8dBV,
Insert Return -10 dBV +6dBV Assumes FX device in loop is set for unity gain Peak
A/D input -10 dBV +4.5dBV Assumes max voltage at the A/D = +6dBV=0dBFS, D/A
D/A output 0 dBV +4.5dBV
Bass Out 0 dBV 0/+4.5dBV
Amp In 0 dBV 0 dBV Nominal levels throughout the system are referenced to
Amp Out 30 dBV 30 dBV This is maximum output at clip level ~250W
+8dB to +50dB
(XLR Balanced Input)
-12dB to +30dB (1/4”
Unbalanced Input)
-40dB to 0dB -10 dB @
-80dB to +22dB +10 dB @
+21dB @
Pot center
+1dB @ Pot
center
Pot center
Pot center
Center vs. Max/Min dependent on Pot
taper.
Center vs. Max/Min dependent on
available Pot tapers.
Adjustment range is restricted and log
taper is implemented by a look-up table,
in order to make this a usable control.
Adjustment range is defined and log
taper is implemented by a look-up table,
in order to make this a usable control.
Adjustable Controls: Gain range and nominal settings
-30dBV unbal
-1dBV dBV
un-bal
+12dBV un-
bal
-50 dBV
balanced
-21 dBV
balanced
-8 dBV
balanced
+6 dBV
balanced
0 dBV +18dBV
-10 dBV +18dBV The nominal gain setting here is -10dB for the volume
- 12 dBV Ch1 / Ch2 Vol. + Master @ 12:00. Maximum input
limited by input INA163 output clipping.
This nominal = the outpu t l eve l of a Shure SM58
microphone that is exposed to 104 dBSPL.
This nominal = the output level of an AKG C4000
microphone that is exposed to 120 dBSPL.
control +20 max out assumes Volume @ Max. (+10 max)
Peak @ 12:00 / Max Volume. Nominal is conservative
but should also work well for cheap stomp boxes
limited by A/D input overload.
output filter gain = -1.5dB
The total excess gain in the DSP will be 16 dB, with a
nominal setting of +10dB. Again we assume 0dBFS =
+6dBV. It is the responsibility of the digital limiter to
ensure that power amp does not clip, i.e. that the output
will not exceed 0 dBV
Limiter engaged (normal operation) / Debug
Bass Out can be used Balanced / Un-balanced
full output power, so nominal & peak are the same
@ 4 ohms
Nominal and Peak Signal Levels
100
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