A bit special, but it works. You can stream all you iPad Output to HQPlayer. Anyway fixed at 44.1/16 as using here Airplay to Mac in combination with BlackHole on Mac. HQPlayer Desktop running on Windows here, but works on Ubuntu Server just the same. Did not dig into this further as much easier to run HQPlayer Desktop on little Macbook Air. But you may get the idear. Maybe dabass has a more optimzed version. Have fun 