I did this too but I want to check my solution if it is right or not, and I need more explanation please help me with that and thanks.

I have to build three stages for the (Audio signal) especially for Musical applications. The three stages that I have to simulate using Multisim software are: Amplification of the signal Filtration of the signal Analog to digital convertion In the above schematic I started with Summer Amplifier with multi frequencies input, then I have the filtration stage (At the output of each filter, you should see the desired input signal based on the filter cut off frequency. For example you should see the first input signal (5KHz) at the output of which filter? I used High pass filter, but it is better to try band pass filter (4 filters for each input signal) you have to design R and C according to the cut of frequency and for sure we should connect the 4 filters in parallel They Analog to digital converter Finally as an Application let's assume it is (musical instrument) I did this too but I want to check my solution if it is right or not, and I need more explanation please help me with that and thanks.