I am using an OPA series audio amplifier, and I want to adjust the gain of the input signal by connecting a variable resistor in the feedback path. However, when I connect either a digital or an analog potentiometer to the feedback network, I observe distortion in the input signal.
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I applied DC and sinusoidal signals to the Op-Amp input, respectively. When I connected a digital potentiometer in the feedback path, I observed that the input signal waveform became distorted at certain resistance values.
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I applied DC and sinusoidal signals to the Op-Amp input, respectively. When I connected an analog potentiometer in the feedback path, I observed that the input signal waveform became distorted at certain resistance values.
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I applied DC and sinusoidal signals to the Op-Amp input, respectively. When I soldered fixed resistors in the feedback path, the gain behaved correctly and the signal remained clean.
In this case, I need to amplify the analog audio signal at the Op-Amp input with adjustable gain. How can I solve this problem?
