Bose FREESPACE BMA-125 Service Manual - Page 16

Browse online or download pdf Service Manual for Amplifier Bose FREESPACE BMA-125. Bose FREESPACE BMA-125 49 pages. Business music amplifier 120/230v

Print Page
Bose FREESPACE BMA-125 Service Manual
12. Input 3, 4
12.1 Perform the test procedure 11, if the
optional input module is installed.
13. MIC PAGE INPUT
µ
13.1 Apply a 800
Vrms, 1KHz signal to
the MIC PAGE INPUT. Rotate the PAGE
LEVEL pot to the full clockwise position.
13.2 Reference a dB meter to the applied
signal.
13.3 Measure the LINE output. It should be
±
60 dB
4 dB.
14. Model 8, 32 EQ
Note: Connect J1 to the EQ PCB. This will
insert the internal EQ. Do this if J1 was
disconnected according to the general test
setup procedure.
14.1 Apply a 100mVrms, 1KHz signal to
Input Five. Move the EQ selector switch to
the Model 8 position.
14.2 Adjust the Master and Input Five gain
controls to obtain a 5Vrms output from the
4Ω output.
14.3 Reference a dB meter to the 4Ω
output. Measure the response according to
the following table.
Frequency
Output
(dB)
20Hz
-20.3
85Hz
13.2
250Hz
3.7
500Hz
.9
1KHz
ref
5KHz
5.8
12.5KHz
12.4
20KHz
2.1
14.4 Move the EQ selector switch to the
Model 32 position. Measure the response
according to the following table.
BMA-125 120V Test Procedures
Tolerence
(dB)
±3
±1.5
±1.5
±1.5
-
±1.5
+.85,-2.15
±3
16
Frequency
Output (dB)
20Hz
-18.4
85Hz
14.5
250Hz
4.3
500Hz
1.2
1KHz
ref
5KHz
9.2
12.5KHz
15.5
20KHz
5.4
230V Variation Tests
Note: Perform all the proceeding tests
except 3, 4 and 5.
1. Remote Master Volume
1.1 Apply a 100mV, 1KHz signal to Input
Five.
Ω
1.2 Connect a 4
1.3 Adjust Input Five and the Master
volume control so that 24Vrms is measured
across the 4Ω load.
1.4 Reference a dB meter to the 4Ω
output.
1.5 Connect a 10KΩ pot to the terminals
marked Remote Master. Rotate the pot to
its minimum resistance position. Measure
the 4Ω output. It should be
2. 100V Output
Note: Remove the 4Ω to PRI jumper and
connect a 80Ω load to the 100V output.
2.1 Apply a 100mVrms, 1KHz signal to the
100V output.
2.2 Adjust Input Five to the full clockwise
position. Adjust the Master volume control
so that 100Vrms is measured across the
80Ω load. The signal should look clean.
Tolerence (dB)
±3
±1.5
±1.5
±1.5
-
±1.5
+.8, -2.2
±3
Ω
load to the 4
output.
≤
-40dB.