The specifications for Stages say It has a refresh rate of 31.25kHz.
A Step or Hold channel with no gate and the pot turned full CCW will alias, with somewhat different character for Step vs. Hold. Turning up the slider will add a DC offset and thus clip it.
In Step mode, turning up the knob will slew (lowpass filter) the audio. in Hold mode, it will delay it but also apply lowpass filtering to it – the longer the delay time, the lower the sample rate, but it will smooth the samples to compensate. (It’s kind of a shame the delay time can’t be modulated from external CV.)
Step mode with a rate is a sample+hold – so with an audio-rate squarewave into the gate, you can control the sample reduction effect.
If you use Hold mode with an audio rate gate, it’s sort of a choppier and filthier version of that, since it’s a gate/trigger generator where the CV input and slider determine the level.
Running audio through gates without a CV input, for envelopes or hold segments (with the slider up), also gets pretty crazy. It was a technique I used a lot with the 0-Coast’s Slope section, but with Stages you have multiple segments to play with, including short holds for a crackle effect