Bose PackLite A1 User manual

1
CONTENTS
Safety Information.............................................................................................................................2
Warranty .............................................................................................................................................2
Product Description ..........................................................................................................................3
Carton Contents ................................................................................................................................3
Amplifier Rear Panel Connections and Controls ...........................................................................4
Top Panel Indicators .........................................................................................................................4
Setting Up a Single A1 Amplifier .....................................................................................................5
Using Multiple A1 Amplifiers ............................................................................................................6
Using the A1 in other applications ..................................................................................................7
Setting up the A1 for use with other systems: ...............................................................................7
Specifications ....................................................................................................................................8
Production Notes ..............................................................................................................................9
Electrostatic Discharge Sensitive (ESDS) Device Handling .........................................................9
Part List Notes ...................................................................................................................................9
Packaging Part List, PackLiteTM A1 Amplifier Assembly (see Figure 1) .....................................10
Figure 1. PackLite A1 Amplifier Assembly Packaging View............................................................10
Main Part List, PackLite A1 Amplifier Assembly (see Figure 2) .................................................. 11
Figure 2. PackLite A1 Amplifier Exploded View ..............................................................................12
Electrical Part Lists ................................................................................................................... 13-29
Power Supply / Amplifier PCB Assembly................................................................................ 13-22
Input / Limiter PCB Assembly .................................................................................................. 23-28
Signal LED PCB Assembly .............................................................................................................29
Power / Fault LED PCB Assembly .................................................................................................29
Disassembly Procedures ......................................................................................................... 30-33
Test Procedures ........................................................................................................................ 33-34
Figure 3. Amplifier/SMPS PCB (Non-RoHS) Topside Etch Layout .................................................35
Figure 4. Amplifier/SMPS PCB (Non-RoHS) Internal Etch Layer 1 Layout ....................................35
Figure 5. Amplifier/SMPS PCB (Non-RoHS) Internal Etch Layer 2 Layout ....................................36
Figure 6. Amplifier/SMPS PCB (Non-RoHS) Bottom Etch Layout ..................................................36
Figure 7. Amplifier/SMPS PCB (RoHS) Topside Etch Layout .........................................................37
Figure 8. Amplifier/SMPS PCB (RoHS) Internal Etch Layer 1 Layout ............................................37
Figure 9. Amplifier/SMPS PCB (RoHS) Internal Etch Layer 2 Layout ............................................38
Figure 10. Amplifier/SMPS PCB (RoHS) Bottom Etch Layout........................................................38
Figure 11. Input/Limiter PCB (Non-RoHS) Top Side Etch Layout ...................................................39
Figure 12. Input/Limiter PCB (Non-RoHS) Bottom Side Etch Layout .............................................39
Figure 13. Input/Limiter PCB (RoHS) Top Side Etch Layout ..........................................................40
Figure 14. Input/Limiter PCB (RoHS) Bottom Side Etch Layout.....................................................40
Figure 15. Power/Fault LED PCB Etch Layout ...............................................................................41
Figure 16. Signal/Overload LED PCB Etch Layout ........................................................................41
Test Cable Wiring Diagrams...........................................................................................................41
Troubleshooting ..............................................................................................................................42
Theory of Operation, PackLite Model A1 Amplifier ................................................................ 43-50
Integrated Circuit Diagrams ..................................................................................................... 51-53
Service Manual Revision History...................................................................................................54

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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)
UL6500 / UL60065 / IEC 60065 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 prod-
ucts, 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®PackLiteTM Model A1 Amplifier
contains no user-serviceable parts. To prevent 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.
The Bose PackLite Model A1 Amplifier is covered by a limited 1-year transferable warranty.
WARRANTY

3
The PackLiteTM Model A1 power amplifier is a small, lightweight, powerful, and easy-to-use
amplifier that interfaces quickly with the Bose®PS1 power stand and B1 bass modules to
provide high bass output for demanding instruments such as bass guitar and drums. The con-
nections are quick and easy: plug in the AC cord, connect the A1 to the PS1 power stand, and
play. When the A1 is used together with the Cylindrical Radiator®loudspeaker, no time-consum-
ing adjustments are required. The components act as a system and automatically adjust bass
output for more level and headroom, while maintaining consistent tone regardless of how many
B1 bass modules are being used.
In addition, the A1 can drive other passive loudspeakers such as bass guitar cabinets,
subwoofers, studio monitors, and floor monitors.
Product Description
•Carrying pouch
•PackLite power amplifier Model A1
•AC power cord
•¼" TRS (balanced) cable (20 inches, 0.5 m)
•Owner’s guide
Carton Contents

4
Amplifier Rear Panel Connections and Controls
1 2 3 4 5
1 - AC power connector: Accommodates the supplied AC power cord to connect your amplifier
to the appropriate AC (mains) outlet. Check the product label of your amplifier for the voltage
rating: 120V or 220-240V.
2 - Power switch: In the ON (l) position, applies power to your amplifier. When ON, the power
indicator (see diagram below) should be BLUE.
3 - OUTPUT connector: Accommodates both 2 and 4-wire Neutrik®Speakon®connectors.
OUTPUT can be connected to any of the following:
• B1 bass module.
• 4-ohm loudspeaker with a power rating of at least 250W RMS.
• 8-ohm loudspeaker with a power rating of at least 125W RMS.
4 - INPUT connector: Accommodates a ¼" TRS (balanced) or TS (unbalanced) plug.
INPUT can be connected to either of the following:
• Bass-Line OUT jack on the PS1 power stand using the supplied ¼" TRS cable.
• THRU connector of an “upstream” A1 amplifier when used in series.
• Other line-level source output using either a ¼" TRS or TS cable.
5 - THRU connector: Accommodates a ¼" TRS or TS connection. Used for sending the INPUT
signal to another A1 amplifier.
Notes:
1. Do not use the THRU connector as a second input, as it could damage any interconnected
equipment. Use THRU only as an output to another A1 amplifier.
2. The THRU connector will only relay the type of input (balanced or unbalanced) present at the
INPUT connector.
Top Panel Indicators

5
The A1 amplifier is designed to add more bass output to a system that already has two B1 bass
modules connected to the Amp 3 OUT connector on the PS1 power stand. The A1 amplifier can
power up to two additional B1 bass modules.
Follow these steps to set up the A1 as shown below.
1. Connect the AC power cord to an AC (mains) outlet.
2. Make sure the A1 amplifier Power switch is OFF.
3. Using the supplied ¼" TRS cable, connect the Bass-Line OUT connector on the PS1 power
stand to the INPUT connector on the A1 amplifier.
4. Connect a B1 bass module cable from the OUTPUT connector on the A1 to a B1 bass mod-
ule. If desired, connect a second B1 to the first B1.
5. Set the A1 power switch to ON (I).
CAUTION: Do not connect more than two B1 bass modules to an A1 amplifier.
CAUTION: Be careful not to connect the A1 amplifier to a B1 bass module that is already
connected to the Amp 3 OUT connector of a PS1 power stand, or to another A1 amplifier.
Note: Using the supplied ¼" TRS cable with your A1 amplifier is recommended. Using
balanced cabling prevents common interconnect noise problems.
Note: Up to four (maximum) B1 bass modules can be stacked in a column. Stacking may
improve acoustic output.
B1 bass
modules
B1 bass
modules
PS1 power stand
Bass-Line
OUT
INPUT
OUTPUT
A1 amplifier
Setting Up a Single A1 Amplifier

6
Using Multiple A1 Amplifiers
To add more bass capability to your system, you can connect multiple A1 amplifiers as shown
below.
1. Connect the AC power cord to an AC (mains) outlet.
2. Make sure the Power switch is OFF.
3. Using the supplied ¼" TRS cable, connect the Bass-Line OUT connector on the PS1 power
stand to the INPUT connector on the first A1 amplifier.
4. Using another ¼" TRS cable, connect the THRU connector on the first A1 amplifier to the
INPUT connector of the next A1 amplifier.
5. Connect a B1 bass module to the OUTPUT connector on each A1 amplifier. If desired,
connect a second B1 to the first B1.
6. Set power switch on both A1 amplifiers to ON (I).
CAUTION: Be careful not to connect the A1 amplifier to a B1 bass module that is already
connected to the Amp 3 OUT connector of a PS1 power stand or to another A1 amplifier.
Note: Up to four (maximum) B1 bass modules can be stacked in a column. Stacking may
improve acoustic output.
B1 bass
modules
B1 bass
modules
1st
A1
2nd
A1
B1 bass
modules
PS1 power stand

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Using the A1 in other applications
The A1 amplifier can be used as a power amplifier in other system configurations.
The A1 can drive other passive loudspeakers including subwoofers, floor monitors, studio
monitors, and guitar cabinets. The A1 can amplify a balanced or unbalanced signal from a line-
level device, such as a mixing console, and drive any loudspeaker load (4-ohm minimum) that is
capable of handling 250W.
Setting up the A1 for use with other systems:
1. Make sure the A1 amplifier Power switch is OFF.
2. Connect a line-level output connector from your source device to the INPUT connector of the
A1 amplifier.
• This could be the line-level output from an electronic crossover, mixing console, electric
bass/electric guitar amplifier head unit, preamp, digital modeler, or studio console line
output.
• You can use either a balanced (TRS) or unbalanced (TS) connection. The amplifier will sense
the type of connection and automatically adjust the overall level.
3. Connect the OUTPUT of the A1 amplifier to:
• Any 4-ohm loudspeaker load capable of handling at least 250 watts RMS.
• Any 8-ohm loudspeaker load capable of handling at least 125 watts RMS.
4. If you want to add an additional A1 for more bass, connect the THRU connector of the first A1
to the INPUT connector of another A1 amplifier using a ¼" TRS cable.
5. Set the A1 power switch to ON (I).
6. Adjust the source level so that the A1 signal indicator flashes green. At a maximum source
level, the A1 signal indicator occasionally flashes red. If the indicator is constantly red,
reduce the source level.
Note: Using the A1 amplifier and its connected B1 bass modules with any source device other
than the PS1 power stand is not recommended.

8
Specifications
Electrical
Power, 4-ohm load: 250 watts RMS (1 kHz, 0.1% THD)
Power, 8-ohm load: 125 watts RMS (1 kHz, 0.1% THD)
Minimum loudspeaker load: 4 Ohms
Signal to noise: 100 dB (20 Hz to 20 kHz)
Voltage gain: 30 dB
Input sensitivity: 1.15 V (+3.4 dBu)
Input sensing: Automatic, balanced/unbalanced level adjust
Input impedance: 55k ohms unbalanced, 110k ohms balanced
Input clipping: 10 Vrms (+22 dBu)
Frequency response: 20 Hz to 20 kHz ± 0.5 dB
THRU output type: Balanced/unbalanced, dependent on
INPUT connection type
Output circuitry: Class D
Protection types: Self-resetting thermal, output short circuit,
and over-current
Typical AC power requirements: 1.8A, 120VAC; 0.9A, 220-240VAC
Peak inrush current: 28A (120VAC)
Mechanical
Dimensions: 5.6" W x 2.3" H x 10.3" D;
140 mm W x 56 mm H x 258 mm D
Weight: 3.0 lbs (1.4 kg)
Packaged Shipping Weight: 5.0 lbs (2.3 kg)
Max. operating temperature: 122°F (50°C)

9
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.
ELECTROSTATIC DISCHARGE SENSITIVE (ESDS)
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.
DEVICE HANDLING
PRODUCTION NOTES
The PackLiteTM A1 amplifier has been manufactured in two versions, a 120V version (product
code 039057) and a 220-240V version (product code 039058).
The early 120V units, serial numbers 039057Z52620201AC to 039057Z52621200AC, are non-
RoHS compliant units. 120V units built after the 5262 Julian date (9/19/2005) are fully RoHS
compliant.
The 220-240V version, product code 039058, is fully RoHS compliant from the initial production
units onward.
The Electrical Parts Lists have non-RoHS and RoHS compliant part numbers in cases where
these parts are different for the two versions of the amplifier. Be sure to use ONLY RoHS com-
pliant repair parts in RoHS compliant products.

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Figure 1. PackLiteTM A1 Amplifier Assembly Packaging View
PACKAGING PART LIST
PackLiteTM A1 Amplifier Assembly (see Figure 1)
9
7
4
5
8
10
6
SKU LABELS (6 UNITS IN
ONE MASTER CARTON)
11
INDIVIDUAL AMPS
IN GIFT BOXES
PE BAGS
1
2
3
Item
Number
Description Bose
®
Part
Number
Vendor Part
Number
Qty. Note
1 Filler, Sheet, 295x168x6, A=B 291589 1450-8830+0 1
2 Owners Manual 287546 4301-7207+0 1
3 Sheet, Warranty / Welcome 287553 3050-3681 1
4 Carry Bag, Nylon 280x150x70 287554 4201-1000+1 1
5 PackLite Amplifier Assembly REF - 1
6 Filler, Lower, 292x167x46 291588 1450-8840+1 1
7 Power Cord, 120V (US/Canada) 263453 - 1 3
Power Cord, L=2.5M, 230V (Europe) 173352 7012-6980+0
Power Cord, 240V (Australia) 264357 -
8 Filler, Upper, 292x167x81 291587 1450-8850+1 1
9 Cable Assy, 1/4" to 1/4", TRS, Stereo
Signal Input, L=500mm
287556 7012-7130+0 1
10 Carton, Single, 4 Color Printed 287550 1480-8201+0 1
11 Carton, Master, 527x304x264mm - 1437-6401+0-2 -
- PE BAG, 8.5x14x0.05 - 1497-4412+0 1
- PE BAG 350x120x0.05 (MIC Cable) - 1497-7762+0 1
- PE BAG 350x120x0.05 (AC Cord) - 1497-7762+0 1
- PE BAG 250x140x0.05 (Manual) - 1497-7772+0 1
- Sheet, Notice - 3050-3701+0 1