I haven’t experimented with upsampling at all — and yes, my ring mod is just two inlets, a *~ and an outlet and it sounds like garbage :)
The material I’m currently working with is a personal library of objects that all accept signals from -1. to 1. and operate on the metaphor of an analog modular — all objects have inputs and outputs in the same range, whether they are intended as audio or "control voltage." I open up these modules in bpatchers and then route them around through a matrix~. One of the situations in which i notice bad quality audio is, for example, when I have one vco modulating another vco in the audio rate (a kind of FM).
I’ll attach a couple of problematic modules — the vco, vca, and the wavetable module — that i’ve noticed as liable to generate undesirable artifacts. I’d appreciate any suggestions for improving their performance.
Any tips on getting into upsampling? where can I learn about how to do it?