Test Procedures - Bose FreeSpace DXA 2120 Service Manual

Test Setup
AC power must be applied to the product variants as follows:
• DXA 2120 amplifiers with part number 294962-1, use 120VAC (+10/-1%), 60Hz
• DXA 2120 amplifiers with part numbers 294962-2, -4, and -5, use 240VAC (+10/-1%), 50Hz
• DXA 2120 amplifiers with part number 294962-3, use 100VAC (+10/-1%), 50Hz
Required Test Equipment
• Audio Signal Generator
• Oscilloscope
• Distortion Meter
• DC Power Supply capable of a 30V @ 2A output level
• Qty 2 - DXA-2120 Wallplates, PC: 041967
Test Conditions
•
All AC audio measurements must be band limited from 22Hz to 22kHz
• All balanced line inputs must be terminated with 50 ohms
• All balanced mic inputs must be terminated with 150 ohms
• Line level output must be terminated with 400 ohms
•
All amplifier outputs must be terminated with appropriate resistor values. See below.
Output Name
4 Ohm Output
70.7 Volt Output
100 Volt Output
Standard test control positions
Set the unit under test controls to the positions listed in the table below.
Control Name
Input 1 Trim
Input 2 Trim
Input 3 Trim
Input 3 Trim
Output 1 Trim
Output 2 Trim
Output 1 Treb
Output 2 Treb
Output 1 Bass
Output 2 Bass
Page Input Trim
Input 1 Mic/Line Switch
Input 2 Mic/Line Switch
Input 3 Mic/Line Switch
Input 4 Mic/Line Switch
Power Switch

TEST PROCEDURES

Load Required
4 Ohms @ 200W
49 Ohms @ 100W
98 Ohms @ 100W
Reference Designator
VR401 Pot
VR402 Pot
VR403 Pot
VR404 Pot
VR405 Pot
VR406 Pot
VR409 Pot
VR411 Pot
VR408 Pot
VR410 Pot
VR407 Pot
SW101 switch
SW102 switch
SW103 switch
SW104 switch
Note
Jumper must be installed between
4 Ohm and Xfmr In
Jumper must be installed between
4 Ohm and Xfmr In
Default Setting
Fully CCW
Fully CCW
Fully CCW
Fully CCW
Fully CCW
Fully CCW
Centered (0dB)
Centered (0dB)
Centered (0dB)
Centered (0dB)
Fully CCW
Line
Line
Line
Line
Off
62