Postulating here, not theorem-tested.
Ad copy says “Standard delay time from 10 seconds to 10 microseconds”, and “modulation sweep from 1/2 to 2x the standard delay time.”
So, that would be 0.05-0.2 Hz. at 10 seconds. The delay multipliers cut the sample rate. I don’t recall if/how that plays into the modulation speeds.
And on the lowest end of the delay scale, I doubt the modulation sweep exceeds the nominal sample rate (100K). But who cares about any inexactness down there? That is the delay area where those gorgeous modulation sweeps live & breathe.
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