I wonder if there's also distortion or ring modulation stages where some of the energy above hearing range might spill into audible sidebands if they're not nyquist-limited first.
replyYeah, that's the "rest of the synth" part that's more vulnerable to aliasing.
replyThere's some ways to do band-limited distortion but...they aren't nearly as widespread, easy, or universal as band-limited oscillators.
Ring modulation is funny though because you'd ideally want the sidebands to modulate down by default rather than filter them out, that's why you're using it.