• dir
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  • Registered: 2018-04-23
  • Posts: 86

Topic: NOS mode for AD recording

I was notice that i can't get a fair impulse response, because ADI-2 always uses some filters for AD-process.
what does it mean? it means that NOS mode always shows some ringing on ADI's recordings, it means that i see non-simmetric impulse from linear phase source, because ADI-2 was made records with Short Delay filter etc.
i didn't have such a problems with my old portable recorder. NOS looks like NOS, impulse from linear-phase filter looks like impulse with simmetric ringing.
is it possible to add Rec mode without filtering?

2 Reply by MC

  • MC
  • MC
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  • From: Germany/Thailand
  • Registered: 2007-04-06
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Re: NOS mode for AD recording

Use sample rates higher than 192 kHz to record and the filters become invisible. At lower sample rates filters are needed or aliasing issues will be too big. That's why you won't find any AD chip that offers such a 'NOS' option. If your old converter worked that way then both frequency response and aliasing must have been affected.

Regards
Matthias Carstens
RME

MC's Website

  • dir
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  • Registered: 2018-04-23
  • Posts: 86

Re: NOS mode for AD recording

it seems that i never see NOS imp in the loopback mode of ADI-2, because it must be set on 44 kHz on both ways. Right?
most of recording software (izotope or spectralab) are use 192 only. I try to make records on highest rate 192 but it still have some ringing from filters on input.

for example, my recorder Sony PCM-D100 in the 24/88 mode shows classic picture from ADI's filters output
http://i.piccy.info/i9/650c6d10243b357093950dc323a4bbfd/1539070036/14296/1274225/imp.png

  • Registered: 2018-07-20
  • Posts: 30

Re: NOS mode for AD recording

What exactly is your recording source and chain?

5 Reply by MC

  • MC
  • MC
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  • From: Germany/Thailand
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Re: NOS mode for AD recording

You would get the same pics using the ADI-2 Pro at 88.2 kHz with filter Slow. Note that the NOS IR shows the limitations of such 'undersampling'. The real signal view is found in the manual, shot at 768 kHz sample rate.

Regards
Matthias Carstens
RME

MC's Website