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FINAL TESTING
REQUIREMENTS FOR FINAL TESTING:
a)
Neutrik
b)
Load 40ohm
c)
Multimeter
d)
Oscilloscope
e)
Microphone
f)
Variac
5.
THD
Setup
Signal generator = 1mVAC, 1kHz
Signal in = Ch1 XLR
Channel pot = min (CCW)
Bass/Treble = centre
Master pot = min (CW)
Output metering = 100Vout
Load = 40ohm
Procedure
Set master pot to max. Turn up Ch1 pot to 70VAC (+/-1.0VAC) on output. Measure
THD.
(P/F) Reading shall be < 0.5%.
Values to be recorded:
Value
Pass
Range
5.
THD
0% – 0.5%
6.
Sensitivity
6.1.
Mic inputs
Setup
Signal generator = 1mVAC, 1kHz
Signal in = Ch1 XLR
Ch1 pot = somewhere
Ch2-4 pots = min (CCW)
Bass/Treble = centre
Master pot = max (CW)
Output metering = 100Vout
Load = 40ohm
Procedure
Set channel pot to max.
(P/F) The output reading shall be 100VAC (+/- 5VAC).
Repeat for all channels.
[Setup for next test] Move the signal in back to channel 1 RCA. Set the signal
generator to 0.5VAC
6.2.
AUX inputs
Setup
Signal generator = 0.5VAC, 1kHz
Signal in = Ch1 RCA
Channel pot = max (CW)