Sorry for the late answer, but I ran in this problem again, not having interfacing anything lately. The spikes are not occurring when I move the pot, but at random. It affects everything. I linked a video of it, the blue line is the sin output from the examples project, the red line is a simple 10k pot into Analog 0 wired to the 3.3v from the Bela. I simply multiply the reading from AnalogIn 0 with the output from the sine wave.
As you can see, the blue waveform is affected without me touching the pot. I tried a lot of them too. And also to change basic settings like sample rate, but it's always like this.
Soundwise, you can hear pops now and then when it's strong enough, but you can hear it when modulating, ie using a pot to FM an oscillator in SC can get quite messy.
So I tried with just the simple sinetone project, and added a scope, and there are tiny spikes too:
Is it me not understanding something ?