Looks good Miska! But just to be clear, my request was to see a MUCH lower frequency sweep of 10kHz to 60kHz, so we can see what is happening just out of band. I know you like to measure and refine your filters at all those supersonic frequencies, but I more interested in what goes on down lower.

Quad-rate sure does seem to be the sweet spot. That's an impressive 7kHz square rise.

Have you been listening to the DSC1 for a while now?

Thanks and regards.

Band below 100 kHz is entirely dictated by the conversion stage filter, roll-off slope steepens as the frequency increases (depending on sampling rate). The Sallen-Key filter kicks in at 100 kHz. Since the conversion stage filter is linear phase, this keeps the phase behavior also in shape.

Yes, I've been listening it for quite a bit. I was actually surprised how good it sounds. And nobody (?) can complain that it would sound good due to ultrasonic noise...