Bose FREESPACE BMA-125, Service Manual

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Frequency Output
(dB)
Tolerence
(dB)
50Hz 0 -2
1KHz ref -
20KHz 0 -2.8
3.5 Adjust Input Five until 11.2Vrms is
measured across the 8
Ω
load. Reference a
dB meter to the output.
3.6 Measure the response according to the
following table.
Frquency Output
(dB)
Tolerence
(dB)
20Hz 0 -2
1KHz ref -
20KHz 0 -2.5
4. 25 Volt Output
Note: Place a jumper between the output
connector labeled “4
Ω
” and the output
connector labeled “PRI”. Connect a 5
Ω
load to the 25V output and the terminal
marked lo.
4.1 Apply a 120mVrms, 1KHz signal to
Input Five. Adjust Input Five to full output
at the 25V output (just before clipping).
4.2 Measure the output. It should be
≥
25Vrms.
4.3 Measure the distortion. It should be
< .5%.
4.4 With the 25V output adjusted to
25Vrms, reference a dB meter to the
output. Measure the response according to
the following table.
Frequency Output
(dB)
Tolerence
(dB)
50Hz 0 -2
1KHz ref -
20KHz 0 -2.5
4.5 Adjust Input Five until 8.875 Vrms is
measured across the 8
Ω
load. Reference a
dB meter to the output.
4.6 Measure the response according to the
following table.
Frequency Output
(dB)
Tolerence
(dB)
20Hz 0 -2
1KHz ref -
20KHz - -2.5
5. 70 Volt Output
Note: Place a jumper between the output
connector labeled “4
Ω
” and the output
connector labeled “PRI”. Connect a 40
Ω
load to the 70V output and the terminal
marked lo.
5.1 Apply a 105mVrms, 1KHz signal to
Input Five. Adjust Input Five to full output at
the 70 Volt output (just before clipping).
5.2 Measure the output. It should be
≥
70.7 Vrms.
5.3 Measure the distortion. It should be
< .5%.
5.4 With the output adjusted to 70.7Vrms,
reference a dB meter to the output. Mea-
sure the response according to the follow-
ing table.
Frequency Output
(dB)
Tolerence
(dB)
50Hz 0 -2
1KHz ref -
20KHz 0 -2.5
6. Tape Output
6.1 Apply a 100mV, 1KHz signal to Input
Five.
6.2 Adjust Input Five to the full clockwise
position.
BMA-125 120V Test Procedures