Pass/Fail Summary
1.
Physical checks
2.
Set up amplifier for test :
2.1.
Fuse check
2.2.
Connections
2.3.
Reset controls:
3.
Power up :
(P/F) Current shall not exceed 0.5Aac.
3.1.
Voltages
(P/F)
Pass
Range
DC power supply
47.5VDC - 50.5VDC
Input PCB rail (p8)
11.0VDC – 13.0VDC
Input PCB ½ rail (p1)
5.0VDC – 6.0VDC
Input PCB ground (p4) -0.1VDC – 0.1VDC
3.2.
Bias setup
(P/F) Slowly adjust the preset PR1 so that you get 4.5mVDC (+/-0.5mVDC)
(P/F) The emitter resistor voltages shall be 4.5mVDC (+/-2.0mVDC).
4.
Initial AC Checks :
4.1.
Signal check and gain of amp
(P/F) The output shall be 15.5VAC +/- 2VAC.
4.2.
Emitter current check
(P/F) Voltage shall be between 300mVDC – 400mVDC.
4.3.
Inputs
4.4.
Outputs
(P/F)
Pass
Range
100V line
90VAC – 110VAC
Tape output – left
200mVAC – 300mVAC
Tape output – right
200mVAC – 300mVAC
Line output
0.65VAC – 0.80VAC
4.5.
Phantom power
(P/F) The reading shall be 12.0VDC +/-1.0VDC.
(P/F) The LED shall be off.
(P/F) The LED shall be on.
5.
THD
(P/F) Reading shall be < 0.5%.
6.
Sensitivity
6.1.
Mic inputs
(P/F) The output reading shall be 100VAC (+/- 5VAC).
6.2.
AUX inputs
(P/F) The output readings shall be 100VAC (+/- 5VAC).
7.
Bandwidth
(P/F) The frequency shall be between 20Hz – 30Hz.
(P/F) The frequency shall be between 20kHz – 40kHz.
8.
Bass/Treble
(P/F) The output reading shall be between 60VAC-70VAC.
(P/F) The output reading shall be between 3VAC-4.5VAC.
(P/F) The output reading shall be between 42VAC-50VAC.
(P/F) The output reading shall be between 4VAC-6VAC.
9.
Phase
(P/F) The signals on the CRO shall be in phase for all outputs (100V, 4ohm).
10.
Priority check
(P/F) The output shall drop in level to < 10VAC.
(P/F) The output shall return to /-10VAC in <10sec (Mental count is
acceptable).