Bose FreeSpace E4 Series II User manual

©2008 Bose Corporation Reference Number 278977-SM Rev. 01
Service Manual
FreeSpace®Business Music System
Model E4 Series II
Digital Signal Processor
and Power Amplifier
Electronic Copy Only

2
CONTENTS
Contents.............................................................................................................................................2
Safety Information.............................................................................................................................3
Warranty.............................................................................................................................................3
Product Description..........................................................................................................................4
Specifications.............................................................................................................................. 5-10
Electrostatic Discharge Sensitive (ESDS) Device Handling .......................................................11
Part List Notes.................................................................................................................................11
Amplifier Module Repair Information ............................................................................................11
Packaging Part List, FreeSpace®E4 Series II Business Music System (see Figure 1) ............12
Figure 1. FreeSpace E4 Series II System Packaging View ..............................................................12
Accessory Kit Part List (not shown) .............................................................................................12
Main Part List, FreeSpace E4 Series II Business Music System (see Figure 2)........................13
Figure 2. FreeSpace E4 Series II Business Music System Exploded View ......................................14
Main Part List, E4 Series II Power Supply / Power Amplifier PCB Module (see Figure 3) .......15
Figure 3. E4 Series II Power Supply / Power Amplifier PCB Module................................................15
Electrical Part Lists................................................................................................................... 16-72
Digital Signal Processor / User Interface PCB Assembly ..................................................... 16-36
E4 Series II Power Supply / Power Amplifier PCB Assembly ............................................... 37-51
FreeSpace 4400 Power Supply / Power Amplifier PCB Assembly........................................ 52-69
FreeSpace 4400 Power Amplifier Driver PCB Assembly ....................................................... 70-72
Disassembly Procedures ......................................................................................................... 73-74
Figure 4. E4 II Amplifier Module Assembly .......................................................................................74
Test Procedure Setup ............................................................................................................... 75-76
Test Procedures ........................................................................................................................ 77-80
Troubleshooting ........................................................................................................................ 81-89
Theory of Operation.................................................................................................................. 90-97
Accessories .....................................................................................................................................98
Figure 5. Flash Memory PCB Component Layout ............................................................................99
Figure 6. DSP PCBAssembly Component Layout ...........................................................................99
Figure 7. Wallplate Sense PCB Assembly Component Layout.......................................................100
Figure 8. Mic Sense PCB Assembly Component Layout................................................................100
Figure 9. Front Panel Display PCB Assembly Component Layout .................................................100
Figure 10. E4 Series II Upper and Lower Amplifier PCB Assembly Component Layout ................101
Figure 11. FS 4400 Upper Amplifier PCB Top Etch and Component Layout..................................102
Figure 12. FS 4400 Upper Amplifier PCB Bottom Etch and Component Layout............................103
Figure 13. FS 4400 Lower Amplifier PCB Top Etch and Component Layout..................................104
Figure 14. FS 4400 Lower Amplifier PCB Bottom Etch and Component Layout ............................105
Service Bulletin ..................................................................................................................... 106-107
Service Manual Revision History.................................................................................................108

3
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®E4 Series II Business Music System 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
BYAN AUTHORIZED BOSE SERVICE CENTER OR OWNER OF
THE BOSE PRODUCT, AND SHALL NOT BE REPRODUCED OR
USED FOR ANY OTHER PURPOSE.
The Bose E4 Series II Business Music System is covered by a limited 5-year transferable
warranty.
WARRANTY

4
PRODUCT DESCRIPTION
E-4 Series II Business Music System
The Bose®FreeSpace®E-4 Series II Business Music System is an integrated four-channel
digital signal processor and 400-Watt power amplifier for 70/100V business music applications.
The E-4 chassis provides a total of four source inputs (two Line In, one Mic/Line and one Mic/
Line/Page) to meet the needs of most business music installations. A Music on Hold (MOH)
output is also provided for simple integration into a phone system.
As a single component, the chassis provides all of the processing and control features required
for one to four zone business music applications. These features include:
• Auto Volume: When used with the optional FreeSpace Auto Volume Sense Mic, the E-4
system dynamically controls the program level in each zone so that the audio program
material can always be heard, regardless of the background noise.
• Scheduling: Allows you to program the E-4 system for automated on/off and source
selections according to time of day or day of week.
• Opti-Voice®Paging: Provides the appropriate sound level regardless of variations in
speech projection.
• Source Leveling: Automatically compensates for variations in source input levels.
• Dynamic Equalization: Maintains tonal balance at all listening levels.
• Room Equalization: Provides easy adjustment of tonal balance in each zone.
• Limiting: Protects loudspeakers from unwanted transient power loads.
• Signal Router: Meets the demands of most four-zone systems, allowing for any input signal
to be routed to any of the amplifier outputs.
• RS-232 Connection: Provides easy interfacing to your PC.
• Contact Closure Input: Allows remote power sequencing.
The integrated 400-Watt power amplifier features a patented power-sharing technology which
allocates power to each output.
For example, if you have a two-zone system that requires 5 Watts in zone 1 and 395 Watts in
zone 2, the FreeSpace E-4 Series II system distributes the power based on those needs.
The E-4 Series II also includes an easy-to-replace memory module, which holds a design file
and the current hardware configuration.

5
SPECIFICATIONS
Audio Input Source 1 unbalanced RCA, shell grounded through a 301 Ohm resistor
Connectors: Source 2 unbalanced RCA, shell grounded through a 301 Ohm resistor
Page balanced 4 pin Beau style: +, -, ground and contact closure in
Aux/Mic/Line 3 pin Beau style, +, - and ground
Mic 1-4 3 pin Beau style, +, - and ground
Direct In 4 pin Beau style, +, -, ground, and contact closure in
Audio Output
Connectors: Line out 4 pin Beau style, +, -, ground, and contact closure in
MOH out 2 pin Beau style, + and Ground
Amp 1-4 2 pin, Beau style, + and -
Control Connectors: Remote 1-4 RJ-45, 8 pin, ground shell
Standby In 2 pin Beau style, contact closure in and ground
Dimensions: 5.25"H x 16.5"W x 15.5"D (13.3 x 43.8 x 39.4 cm)
Weight: 30 lbs (13.6 kg)
AC Mains input: IEC standard User selectable 100/120 or 220/240V
3 pin 50/60 Hz
receptacle 300 Watts maximum
Overall Performance
Nominal Limits Conditions
Gain: 0 dB +1 dB at 1 kHz; input gain set to nominal 0 dB
Dynamic range: 100 dB >/= 96 dB measured with ADC/DAC full scale mapped to
+17 dBV; this is THD +N measured at FS-60,
through A-weighting filter, and expressed in dB
below full scale
THD+N: .05% .1% at +10 Vrms output, for signal frequencies from
30 Hz to 20 kHz
Crosstalk at 1 kHz: -80 dB </= -70 dB terminate unused input terminals with 100 Ohm
balanced-connected resistors.
Crosstalk at 10 kHz: -60 dB </= -50 dB terminate unused input terminals with 100 Ohm
balanced-connected resistors.
Frequency response: 30 - 20 kHz +3 dB reference 1 kHz, measured at 0 dBV input
Output noise: -70 dBV </= -65 dBV channel noise measured through an A
weighting filter. Gain structure set to deliver
rated power and expressed in dBV

6
SPECIFICATIONS
Line Input Source 1 and 2
Nominal Limits Conditions
Source impedance: 200 Ohms 10 to 2k Ohm frequency response specification maintained
with sources over this range
Input impedance
differential: +/> 50k Ohm +/-20% at 1 kHz
CMRR referred to 80 dB >/= 74 dB at 1 kHz, 20 dB gain, 200 Ohm source
output: impedance
Input sensitivity for -20 dBV to +/-1 dB at 1 kHz
codec FS: +17 dBV
Gain, all settings: 20 dB to +/-1 dB 1 kHz, 50 Ohm source
-20 dB
Maximum input level: +17 dBV >/= +17 dBV THD+N </= 0.3%, 30-20 kHz, 0 dB gain
THD+N: .001% .01% at +10 dBV output, 1 kHz, 20 dB gain
Crosstalk at 1 kHz: -90 dB </= -80 dB
Crosstalk at 10 kHz: -70 dB </= -60 dB
Frequency response: 30 to 20 kHz +/-1.5 dB reference 1 kHz, measured at 20 dB gain and
with 0 dBV output
Page and Aux/Mic Inputs
Nominal Limits Conditions
Source impedance: 200 Ohms 10 to 2k Ohm frequency response specification maintained
with sources over this range
Input impedance
differential: 20k Ohm +/-5% at 1 kHz
Equivalent input noise at 60 dB, at 60 dB, A-weighted RMS, 200 Ohm source
at INA129 gains of 60 -130 dBV -127 dBV termination
dB, 40 dB, 20 dB and at 40 dB, at 40 dB,
0 dB: -127 dBV -125 dBV
at 20 dB, at 20 dB,
-115 dBV -113 dBV
at 0 dB, at 0 dB,
-96 dBV -93 dBV

7
SPECIFICATIONS
Page and Aux/Mic Inputs (continued)
Nominal Limits Conditions
CMRR referred 90 dB >/= 70 dB at 1 kHz, 60 dB gain, from source of nominal
to output: 200 Ohms
Input sensitivity for -60 dBV to +/-1 dB at 1 kHz
codec FS: +17 dBV
Gain, all settings: 20 dB to +/-1 dB 1 kHz, 50 Ohm source
-20 dB
Maximum input level: +17 dBV >/= 10 dBV THD+N </= 0.3%, 20-20 kHz, 0 dB gain
THD+N: .001% .01% at +10 dBV output, 1 kHz, 60 dB gain
Crosstalk at 1 kHz: -90 dB </= -80 dB
Crosstalk at 10 kHz: -70 dB </= -60 dB
Frequency response: 30 Hz to +0/-0.5 dB Reference 1 kHz, measured at 60 dB gain and
20 kHz with 0 dBV output
Sense Mic inputs
Nominal Limits Conditions
Source impedance: 200 Ohms 10 to 2k Ohm frequency response specification maintained
with sources over this range
Input impedance
differential: 20k Ohm +5% at 1 kHz
Equivalent input noise at 60 dB, at 60 dB, A weighted RMS, 200 Ohm source termination
at INA129 gains of 60 -127 dBV -125 dBV
dB, 40 dB and 20 dB: at 40 dB, at 40 dB,
-115 dBV -112 dBV
at 20 dB, at 20 dB,
-96 dBV -93 dBV
CMRR referred
to output: 90 dB >/= 60 dB at 1 kHz, 60 dB gain, from source of nominal
200 Ohm
Phantom power: +12V +/-1V open circuit
Input sensitivity for -60 dBV to +/-1 dB at 1 kHz
codec FS: +20 dBV
Gain, all settings: -60 dB to +/-1 dB 1 kHz, 50 Ohm source
+20 dB

8
SPECIFICATIONS
Sense Mic inputs (continued)
Nominal Limits Conditions
Maximum input level: +10 dBV >/= 7 dBV THD+N </= 0.3%, 20-20 kHz, 0 dB gain
THD+N: -84 dB </= -80 dB at +10 dBV output, 1 kHz, 60 dB gain
Crosstalk at 1 kHz: -90 dB </= -80 dB
Crossalk at 10 kHz: -70 dB </= -60 dB
Frequency response: 20 Hz to +0/-0.5 dB reference 1 kHz, measured at 60 dB gain and
20 kHz with 0 dBV output
Direct Input
Nominal Limits Conditions
Source impedance: 200 Ohms 10 to 2k Ohm frequency response specification maintained
with sources over this range
Input impedance
differential: +/> 10kOhms +/-20% at 1 kHz
CMRR referred
to output: 92 dB >/= 60 dB at 1 kHz, 20 dB gain, 200 Ohm source
impedance
Input sensitivity -20 dBV to +/-1 dB at 1 kHz
for codec FS: +17 dBV
Gain: 0 dB +/-1 dB from input connector to amplifier input stage
Maximum input level: +17 dBV >/= +17 dBV THD+N </= 0.3%, 30-20 kHz, 0 dB gain
THD+N: .001% .01% at +10 dBV output, 1 kHz, 20 dB gain
Crosstalk at 1 kHz: -90 dB </= -80 dB
Crosstalk at 10 kHz: -70 dB </= -60 dB
Frequency response: 30 Hz to +0/-0.5 dB reference 1 kHz, measured at 20 dB gain and
20 kHz with 0 dBV output
Line Outputs
Nominal Limits Conditions
Output impedance: 200 Ohms +/-1% impedance at 1 kHz, each output
terminal
Maximum output level: +17 dBV >/= +17 dBV 1 kHz, THD less than 0.1%, load 10 k Ohm,
differential

9
Line Outputs (continued)
Nominal Limits Conditions
CMRR referred
to output: 92 dB >/= 60 dB at 1 kHz, 20 dB gain, 200 Ohm source
impedance
Output noise: -90 dBV </= -85 dBV A-weighted, set for 0 dB gain
THD+N: .001% .01% at +10 dBV output, 1 kHz, 20 dB gain
Crosstalk at 1 kHz: -90 dB </= -80 dB set for 0 dB gain, no limiting, terminate the
unused input with a 50 Ohm resistor
Crosstalk at 10 kHz: -70 dB </= -60 dB
Frequency response: 30 Hz to +0/-1.0 dB reference 1 kHz, measured at 20 dB gain and
20 kHz with 0 dBV output
Turn on/off pop: 10 mV peak </= 50 mVpk as monitored by a listener, must be inaudible at
full gain using a Model 32 loudspeaker tapped
at 32W, with the unit set for no EQ and the
loudspeaker 3 feet from listener
Music on Hold (MOH)
Nominal Limits Conditions
Output impedance: 400 Ohms +/-1% impedance at 1 kHz
Maximum output level: +17 dBV >/= +17 dBV 1 kHz, THD less than 0.1%, load 10 kOhm,
differential
Output noise: -90 dBV </= -85 dBV A-weighted, set for 0 dB gain
THD+N: .001% .01% at +17 dBV output, 1 kHz, 0 dB gain
Crosstalk at 1 kHz: -90 dB </= -80 dB set for 0 dB gain, no limiting, terminate the
unused input with a 50 Ohm resistor
Crosstalk at 10 kHz: -70 dB </= -60 dB
Frequency response: 20 Hz to +0/-1.0 dB reference 1 kHz, measured at 0 dB gain and
15 kHz with 0 dB output
Turn on/off pop: 10 mV peak </= 50 mVpk as monitored by a listener, must be inaudible at
full gain using a Model 32 loudspeaker tapped
at 32W, with the unit set for no EQ and the
loudspeaker 3 feet from listener
SPECIFICATIONS

10
Power Amplifier
Nominal Limits Conditions
Power bandwidth: 30 Hz to 1% THD loaded at 25 Ohms
20 kHz
Frequency response: 30 Hz to +/-3 dB output voltage of 10 Vrms over a load
20 kHz impedance of 12.5 Ohms to 1000 Ohms
THD+N at 70.7 Vrms, .05% .1% 30 Hz to 20 kHz, 25 Ohm load, A weighted
200W:
THD+N at 70.7 Vrms, .5% 1% 7 kHz, 12.5 Ohm load, A weighted
400W:
THD+N at 100 Vrms, .05% .1% 30 Hz to 20 kHz, 25 Ohm load, A weighted
200W:
THD+N at 100 Vrms, .5% 1% 7 kHz, 12.5 Ohm load, A weighted
400W:
Sensitivity at 70V: 11 dBV +/-1 dBV
Sensitivity at 100V: 14 dBV +/-1 dBV
Gain: 26 dB +/-0.5 dB
Output noise: -70 dBV -65 dBV A-weighted with a 20 kHz filter
Crosstalk at 1 kHz: -90 dB </= -80 dB set for 0 dB gain, no limiting, terminate the
unused input with a 50 Ohm resistor
Crosstalk at 10 kHz: -70 dB </= -60 dB
Turn on/off pop: 10 mV peak </= 50 mVpk as monitored by a listener, must be inaudible at
full gain using a Model 32 loudspeaker tapped
at 32W, with the unit set for no EQ and the
loudspeaker 3 feet from listener
SPECIFICATIONS