Hi Elia,
it can be LFO bleed thru (even in bypass) -> set LFO low freq if not used
it can be clock noise, typical related to Freq setting and especially audible in Filter2
this should not be there in bypass -> when making deep bass sounds, cu toff the highs on your desk
When F1 is on minimum, the interference noise should be less while turning F2 (ADSR amounts on 0)
Sometime it seems the pot is noisy.
Plug in a keyboard that has Pitch wheel and Mod wheel transmitting on MIDI ch 16.
Try different F1 F2 knob positions, and turn the wheels, they should control F1 and F2.
If the same 'radio like' noises appear, there is nothing wrong with the pot's, it's all typical :
all filterbanks have this, especially the older ones
