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.
http://ovh.to/iw9ZH5g
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:
http://ovh.to/Mkwp775
Is it me not understanding something ?