WhitakerAudio JC Whitaker 20 W Stereo Integrated Audio Amplifier, Руководство пользователя

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20 W Stereo Integrated Audio Amplifier
14) Set the generator to produce 1 kHz at 1 V rms. Set the Treble control to the flat position (as
just identified). Adjust the Volume control to produce 1.5 V rms at the speaker terminals. Set
the audio voltmeter to read 0 dB.
15) Change the generator setting to produce 20 kHz. With the Treble control set to the flat
position, the meter should still read 0 dB (within about 1 dB). Turn the Treble control to the
full “cut” position (counterclockwise). The observed output on the audio voltmeter should
drop by about 10 dB. Move the Treble control to the full “boost” position (clockwise). The
observed output on the audio voltmeter should increase by about 10 dB. Return the Treble
control to the flat position.
16) Repeat the previous Treble cut/boost measurement on the right channel. The performance of
the two channels should be identical, or at least very close.
11) With the Bass and Treble controls set to their flat positions, adjust the generator to begin the
sweep at about 20 Hz and end the sweep at about 20 kHz. Begin a repetitive linear sweep of
about 1 second duration. Observe the right channel performance. It should be within about
+/–1 dB.
12) Adjust the signal generator to produce a 1 kHz tone at 1 V rms. Adjust the Volume control to
produce an output of 2.8 V rms at the right channel speaker terminals. Set the audio
voltmeter to read 0 dB. Move the Balance control and observe the result on the audio
voltmeter. The output of the right channel should swing from about 2 dB of boost to full cut
(no signal output).
13) Connect the generator output to the left channel Line input and connect the audio voltmeter
input to the left channel speaker terminals. Move the Balance control and observe the result
on the audio voltmeter. The output of the left channel should swing from about 2 dB of boost
to full cut (no signal output).
Note that the effect of the Balance control is influenced by the setting of the Volume control.
As the Volume control is advanced clockwise, the effect of the Balance control boost tends to
increase.
Measurements have now been completed on the tone control preamplifier.