hi all,
I'm developing a simple circuit that converts the output of an audio card into the working voltage range of an ADC (0-3.3V). Well, my input is an audio signals and I'm also interest in cutting-off the high frequencies (higher than 20 Khz). The input signal is alternate with a peak-to-peak voltage of about 0.7 V. Can someone tell me if this circuit can do the necessary task?

 

Almost, I see a low pass filter, no rectifiers.

Do yourself a favor, go with something like LM723, a quad that doesn't need nearly the voltage range. It's much easier to work with.

What is the goal again? To feed an audio signal into an Analog to Digital Convertor?

 

yes the goal is to feed the audio signal to the ADC trying to lose the smaller percentage of components as possible. About the amplifier I'm quite bound to the ua741cp because at the moment is the only model that I've. if necessary I can buy something different but if I can succeed with them I'll happier!
Do you think these operationals are not good at all, or only more complex to manage?