1 (edited by Danros 2022-01-27 16:28:41)

Topic: AI4S AIO High Frequency noise while running on 192khz

So recently I got an AI4S/192 AIO to get some more inputs for my trusty old HDSP 9632 (also have an AO4S/192 AIO and an ADI-2 Pro FS R over optical SPDIF hooked up to it). Now when running the system on 192khz the new AI4S shows high frequency noise at -50db from around 45khz up (see screenshot attached) regardless of whether anything is plugged in or not, clock source or other settings.

I usually record and monitor at 96k so I never noticed it before, but today I switched to the ADI as clock source and tried different sample rates and filter settings on it, and as soon as the system runs higher than 96 the AI4S' noise becomes obvious in Digicheck and Totalmix. Any idea what could cause it?

https://i.imgur.com/8Dzsyim.jpg

HDSP9632, ADI-2 PRO FS R BE, AI4S, AO4S, QuadMic II

Re: AI4S AIO High Frequency noise while running on 192khz

It is as expected as far as I remember, even in the manual.

Vincent, Amsterdam
https://soundcloud.com/thesecretworld
Babyface pro fs, HDSP9652+ADI-8AE, HDSP9632

Re: AI4S AIO High Frequency noise while running on 192khz

Yep!
Interference gets picked because of broader frequency range! Of course, way above human hearing!!

RME Gear: Digiface USB, HDSP 9632

Re: AI4S AIO High Frequency noise while running on 192khz

Well I didn't find anything about it in the AI4S manual. In the HDSP's manual it says -82db noise for its own inputs at 192khz which is actually spot on for my inputs 1/2 on it. But the AI4's input noise (3 to 6) is significantly higher at -50db which is why I'm asking whether this is to be expected for the expansion card or maybe something else is going on. Next question would be how to best deal with the noise since unlike the ADI-2 I don't think there are filters available before the DAW in Totalmix or the Hammerfall settings. So I guess just put a low pass on all recorded tracks in the DAW then?

https://i.imgur.com/jP63dVd.jpg

HDSP9632, ADI-2 PRO FS R BE, AI4S, AO4S, QuadMic II