When playing audio in passthrough mode (line in -> headphones out) on the Pynq Z2, I seem to be getting quite a lot of “electronic” noise (buzzes, clicks and pops rather than white noise hiss).
This occurs whether I am using the base overlay, or my own overlay which handles the audio I2S streams in quite a different way in detail.
As expected, the noise goes away if I mute the codec output.
Does anyone have any suggestions on how to overcome or reduce this noise?
(Audio noise gating doesn’t really help, as the noise is audible even when sound is playing).
Is it likely to be something inherent in the layout of the Pynq Z2 board? Or is it perhaps due to timing glitches causing missed / repeated samples? I’d readily believe that of my own overlay, but as the base overlay also shows a similar kind of noise (although different in detail), it seems less probable this is the cause.
Any suggestions gratefully received. Thanks!