WhitakerAudio JC Whitaker 20 W Stereo Integrated Audio Amplifier, Manual

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power. All measurements described in this User/Assembly Manual are with an input line voltage
of 120 V ac.
7.2.4 Crosstalk
Crosstalk is a parameter that identifies the amount of signal applied to one channel that may
appear in the other channel. This parameter is not specified in Table 7.2 since nearly all stereo
material has a high correlation between channels. In any event, it may be measured as follows:
• Connect a suitable resistive load to each channel. Set the Input switch to Line Input. Set
the Volume control fully clockwise.
• Apply a 1 kHz signal at 1.0 V rms to the right channel Line input. (This will result in about
10 W output.) Connect an audio voltmeter to the right channel output. Adjust the meter to
read 0 dB on a suitable scale.
• Move the 1 kHz signal to the left channel Line input. Place a shorting plug in the right
channel input jack.
• Using the audio voltmeter, measure the residual signal, which will be a combination of
noise and crosstalk from the left channel into the right channel. A reading of
approximately –75 dB is typical for this amplifier.
• Return the audio voltmeter sensitivity switch to the previous setting (10 W). Connect the
voltmeter to the left channel output. Adjust the meter to read 0 dB.
• Move the 1 kHz signal to the right channel Line input. Place a shorting plug in the left
channel input jack.
• Using the audio voltmeter, measure the residual signal, which will be a combination of
noise and crosstalk from the right channel into the left channel. A reading of –75 dB is
typical for this amplifier.
7.2.5 Square Wave Performance
The square wave response of the amplifier can be measured if desired. Two measurement points
are recommended: 1 W output (roughly equal to the “average listening level”) and 10 W (the
maximum rated output of the circuit) into an 8
Ω
load. Typical measurements are shown in Figure
7.2. Performance of the right and left channels should be essentially identical.