I was looking at an amplifier schematic and saw a curious portion that I realized I wasn't sure what its purpose was.
At first glance I thought I saw a low pass filter, but then I said wait no, those are in parallel. What's that capacitor doing there? Is it smoothing the audio source, acting as some kind of noise filter? Is there a name for this kind of device? Would any assumptions need to be made (like whether the audio source has a constant current, or constant voltage or neither) to determine the function of this device? I was operating under the assumption of direct current and audio was encoded as time varying voltages, but if that's not the case, would the circuit do anything different? I saw some things thrown around online like smoothing capacitor, so on an audio signal would it just smooth out sharp peaks? Would this be make it sound nicer, like how a sine wave sounds different than a square or triangle wave?
What would the difference be if I skipped that and connected the audio source directly to my NODE1 there?