Bose FREESPACE BMA-125 Service Manual - Page 15

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Bose FREESPACE BMA-125 Service Manual
6.3 Measure the Tape Output. It should be
1Vrms ( -.21, +.26).
7. Mixer Output
7.1 Apply a 100mVrms, 1KHz signal to
Input Five.
7.2 Adjust Input Five to the full clockwise
position.
7.3 Measure the Mixer Output. It should be
1Vrms (-.2, +.29).
8. Line Output
8.1 Apply a 100mVrms, 1KHz signal to
Input Five.
8.2 Adjust Input Five to the full clockwise
position.
8.3 Measure the line output. It should be
.93Vrms (-.19, +.17).
9. Master Volume Control Range
9.1 Apply a 105mVrms, 1KHz signal to
Input Five. Adjust the Master volume
control to the full clockwise position. Adjust
Input Five to full output (just before clip-
ping).
9.2 Reference a dB meter to the 4Ω
output.
9.3 Rotate the Master volume control to
the full counter clockwise position.
9.4 Measure the 4Ω output. It should be
≤ -50 dB.
10. Mute Control Attenuation
10.1 Apply a 105mVrms, 1KHz signal to
Input Five. Adjust the Master volume
control to the full clockwise position. Adjust
Input Five to full output (just before clip-
ping).
BMA-125 120V Test Procedures
10.2 Reference a dB meter to the 4Ω
output.
10.3 Short the two screws labeled mute
together.
10.4 Measure the 4Ω output. It should be
≤
- 70dB.
11. Input 1 and 2: 400
Input
µ
11.1 Apply a 400
Vrms, 1KHz signal to
Input 1 or 2. Move the selector switch to
the Mic setting.
11.2 Reference a dB meter to the applied
signal.
11.3 Measure the Line Output. It should be
±
67 dB
1 dB.
11.4 Reference a dB meter to the Line
Output.
11.5 Change the input signal to 20Hz. With
the Mic EQ switch in the FLAT setting,
measure the Line Output. It should be
±
-5.3 dB
2 dB. With the Mic EQ switch in
the LOCUT setting, it should be -24.8 dB
± 4 dB.
11.6 Change the input signal to 20KHz.
With the Mic EQ switch in the FLAT setting,
measure the Line Output. It should be
±
-1 dB
1 dB. With the Mic EQ switch in
the LOCUT setting, it should be -1 dB
±
1 dB.
11.7 Apply a 100mV, 1KHz signal to the
INPUT 1 RCA jack or 1Vrms, 1KHz to
INPUT 2.
11.8 Move the selector switch to the AUX
setting. The LINE output should be clean.
Note: Perform the AUX test on both
channels for the 220V variation.
15
µ
V Microphone