6. Test Procedure
1)
Test Equipment:
1.Frequency transformer 2.Digital voltage meter 3.AP ( Audio precision ) 4.Oscilloscope
5.Two
8
Ω
(400W) load
2)
Test procedures and specification
1.Set LIMITER and BRIDGE switches at OFF, turn VR of CH1 and CH2 to maximum, then turn on the power switch and the
blue power LED lights up, and OPERATING/PROTECTION LED shows red then become green after 2-5 seconds or so.
2. Applied no signal, adjust R1-16(CH1) and R2-16(CH2) so that the voltage of R1-17/2-17 is 138
±
2mV. Connect a 4
Ω
load
at output, input a 5KHz signal into CH1 or CH2, adjust the signal so that the output is 5VP-P (about 2VRMS), verify the curve
on oscilloscope and there shall be no crossover distortion. Adjust the output signal level so that the distortion on oscilloscope
is about 1.5-2%, adjust R1-20, R1-21(CH1) and R2-20, R2-21(CH2) so that the crossover distortion reaches its peak (note:
the power supply shall be remained in 230V).
3. Input a 1KHz,
－
4dB signal, the output shall be 48V+/-0.5V and the distortion shall be less than 1%. Using the
multifunctional meter to measure two pins of JP1_14(JP2_14), the voltage shall be increasing up (about 10V at first). Using a
tweezers to short D1_18 (2_18), the overheat protection will start (no signal output).
4.To short the output terminal, the LIMITER on front panel is lit, the power consumption is less than 485W while in short
protection.
5.S/N: larger than 90dB(A weighted is more than 102dB)
6. Compressor function test: LIMITER switch is set at ON, input a 1KHz / +12dB signal, the LIMITER LED is lit in yellow and
there is no clipped signal.
7.Adjust the VR on front panel so that the output is 2V(4
Ω
). The measured frequency response is more than 30Hz to 20
kHz+/-1dB (CH1/CH2).
8.Press the BRIDGE switch down, input a 1KHz signal into CH1(the level control of CH2 is turn to minimum), connect a 8
Ω
load to output terminal, measure the bridged output voltage is more than about 85V and the distortion is less than 1%. (This
measurement shall be done in a minute).
9.Turn off the input signal, the power consumption shall be less than 85W.
10.
Done
