Test Procedures - Bose TouchTunes Service Manual

Note: The following tests are intended to
be used by a qualified electronic technician
to service an amplifier module. These
procedures are not intended to be used in
the field.
ZONE 1 Bass Channel Test Procedures
®
Note: Use the AM-5 P audio input cable, part
number 172296, to connect the test equip-
ment to the input (J5) of the amplifier. Discon-
nect the speakers from the amplifier outputs
and do not load the outputs unless otherwise
noted.
Unit Turn On Procedure
Apply 12 VDC to J5 pin1 (refer to the
schematic). This will simulate the turn-on
signal the amplifier receives from the
computer.
1. Bass Channel DC Offset
1.1 Disconnect all audio input signals.
1.2 Measure the woofer channel output. It
should be 0 ± 70 mVDC.
2. Bass Channel Output Noise
2.1 Short all audio inputs.
2.2 Measure the woofer channel output. It
should be <10 mVrms.
3. Bass Channel Reference Gain
3.1 Apply a 200 mVrms, 100 Hz signal to
the left and right input.
3.2 Reference a dB meter to the applied
signal.
3.2 Measure the bass channel output. It
should be 28.3 dB ± 1.5 dB.
4. Bass Channel Relative Frequency
Response
4.1 Apply a 200 mVrms, 100 Hz signal to
the left and right input.

TEST PROCEDURES

5. Bass Channel Dynamic Equalizer Gain
6. Bass Channel Small Signal Distortion at
0.5 W (1.414 Vrms)
7. Bass Channel Large Signal Distortion at
80 W (17.9 Vrms)
6
4.2 Reference a dB meter to the woofer
channel output.
4.3 Measure the woofer output according to
the following table.
Frequency Output
20 Hz -21.3 dB
40 Hz +3.0 dB
100 Hz Reference
200 Hz -24.5 dB
5.1 Apply a 2.4 mVrms, 50 Hz signal to the
left and right input.
5.2 Reference a dB meter to the bass
channel output.
5.3 Apply a 240 mVrms, 50 Hz signal to the
left and right input.
5.4 Measure the bass channel output. It
should be 26.3 dB ± 1.5 dB (referenced to
the measurement taken in 5.2).
6.1 Connect the speaker or a 6 Ω, 1%,
100 W resistive load to the bass channel
output.
6.2 Apply a 54 mVrms, 100 Hz signal to the
left and right input.
6.3 Measure the distortion at the bass
channel output. It should be <0.5% THD.
7.1 Connect the speaker or a 6 Ω, 1%,
resistive load to the bass channel output.
7.2 Apply a 685 mVrms, 100 Hz signal to
the left and right input.
7.3 Measure the distortion at the bass
channel output. It should be <0.2% THD.
Tolerance
± 2.0 dB
± 1.5 dB
-
± 2.0 dB