Bose 802 E Service Manual

1        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.
Contents
Safety Information ............................................................................................................................. 2
Electrostatic Discharge Sensitive...

2             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 par ts 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. Refer  to Par...

3
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...

4 Dimensions:1.63" H x 19.0" W x 10" D (4.14 x 48.3 x 25.4 cm)
Weight:5.5 lbs. (2.5 kg.)
Chassis material:16 gauge steel with painted/zinc coated finish
Cover plate material:Brushed aluminum, painted
Input Connections:Balanced  XLR
Output Connections:Balanced high frequency and low frequency XLR
 Input Impedance:Balanced input, -10 dB level: 14 k 

Balanced input, +4 dB level: 6 k 

Unbalanced input (+ input used), -10 dB level: 12 k 

Unbalanced input (+ input used), +4 dB level: 4 k 
...

5
THEORY OF OPERATION
This discussion is an electrical overview of the 402® and 802® controllers. Equalization curves
are referenced and are located in the back of this manual. Additionally, the block diagram and
schematic diagrams should be referenced as required.
1. Differential Input Stage
The input stage features protection against RFI (radio frequency interference), ESD (electro-
static discharge), and overvoltage. Referring to the channel 1 circuit,  R2/C1, R1/C120, R3/C2,
and R9, R10/C7 provide...

6 6. Output stage
NOTE: The components mentioned in this paragraph are for the high frequency output only.
The output stage is compatible with balanced signal transmission systems. Inver ting op-amp
stage U9 (pins 1, 2, and 3)  provides the output signal. Diodes D9, D10, D29 and D30 provide
output clamping to protect against overvoltage and ESD. Relays K1 and K2 clamp the outputs
to ground to protect against power on/off transients. When the relay is de-energized, as when
the AC power is off, the outputs...

7 With a nominal AC power input voltage (100, 115, or 230, depending on the country), the AC
voltages at the transformer secondary should be:
between P3-1 and P3-3:  41.3 Vrms
With a cold (i.e. -room temperature) power transformer, you should expect primary and second-
ary resistances of:
For the 100 VAC version:
between P2-1 and P2-2:  41.8 

between P3-1 and P3-3:  6.9 

For the 115 VAC version:
between P2-1 and P2-2:  45.4 

between P3-1 and P3-3:  6.3 

For the 230/240 VAC version:
between P2-1 and...

8
THEORY OF OPERATION
Figure 1. Block Diagram 

9
DISASSEMBLY/ASSEMBLY  PROCEDURES
402® and 802® 

 First Variation (Removable Front Panel)
1. Top cover Removal
1.1 Remove the two screws (7) that secure
the top cover (2) to the front panel (9).
1.2 Remove the two screws (1) that secure
the top cover to the rear of the chassis.
1.3 Lift up the rear of the top cover and
slide it out from under the front panel.
2. Top cover Replacement
2.1 Place the top cover (2) onto the unit and
slide it under the front panel (9).
2.2 Secure the rear of the top cover...

10
DISASSEMBLY/ASSEMBLY  PROCEDURES
7. Transformer Removal
7.1 Perform procedure 1.
7.2 Disconnect the two wire harnesses (P2)
and (P3) from the transformer to the PCB.
7.3 Remove the two 11/32” hex nuts (12)
that secure the transformer (13) to the
chassis.
7.4 Lift the transformer up and away from
the chassis.
8. Transformer Replacement
8.1 Place the transformer (13) into the
chassis aligning it to the studs.
Note: Proper orientation is required for the
transformer wire harnesses.
8.2 Secure the...