WhitakerAudio JC Whitaker 20 W Stereo Integrated Audio Amplifier, Manual

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20 W Stereo Integrated Audio Amplifier
Baseline measurements for the tone control preamplifier are listed in Table 7.7 .
The preamplifier PWB with the daughter board attached draws approximately 50 mA at a
supply voltage of +35 V dc.
Table 7.6 Baseline Performance of Front Panel Auxiliary Buffer Amplifier
Measurement Conditions:
Input signal applied to CONN106
Input voltage = 0.5 V rms
Frequency = 1 kHz
Output taken at CONN107
Output voltage = 1.1 V rms (R164/R171 fully CW)
V+ supply voltage = +23.9 V dc
Parameter Baseline Performance
Frequency response, +/–1 dB 10 Hz to 50 kHz
THD 0.3%
IMD 0.1%
Noise unweighted –85 dB
Clipping point (as observed on an oscilloscope) at 1 kHz 5 V rms output (input = 2.5 V rms)
Table 7.7 Baseline Performance of Tone Control Preamplifier
Measurement Conditions:
Input signal applied to CONN103
Input voltage = 0.3 V rms
Frequency = 1 kHz
Output taken at CONN104/CONN105
Output voltage = 1 V rms (R156/R157 fully CW)
V+ supply voltage #1 = +28.6 V dc
V+ supply voltage #2 = +23.9 V dc
Parameter Baseline Performance
Frequency response (Bass and Treble controls set to “flat”), +/– 1
dB
6 Hz to 550 kHz
Maximum Bass boost (20 Hz) +14 dB
Maximum Bass cut (20 Hz) –11 dB
Maximum Treble boost (20 kHz) +9 dB
Maximum Treble cut (20 kHz) –11 dB
THD (flat response) 0.3%
IMD (flat response) 0.01%
Noise unweighted, shorted input terminals –75 dB
Clipping point (as observed on an oscilloscope 3 V rms output (input = 1 V rms)