• Registered: 2009-07-26
  • Posts: 47

Topic: Line Out Level Of ADI-2 DAC FS To Keep Max Resolution In Studio Use ?

Hi

I got the ADI-2 DAC FS for two weeks now and I'm very happy.

My old studio setup was Fireface 800 and now I'm with the ADI-2 DAC FS, but I Cann't figure out how to set the level out of the ADI-2 DAC FS!!

On the Fireface 800 it is very simple +4dBu is selected and as known it is Studio standard Level, also I'm using Heritage Audio Baby R.A.M for controlling out volume to my amplifier, and in the Fireface 800 main out Fader it is set to 0.

Many years ago there was a knowledge that setting the Fireface 800 to 0 of the output level should keep the higher resolution of the Fireface 800 DA convertors by using external volume controller, now in the ADI-2 DAC FS there is no +4dBu only -5dBu +1dBu +7dBu +13dBu ( I'm aware that the XLR out of the ADI-2 DAC FS is +6dB higher )

So the achieve same level of the Fireface 800 I need to lower the volume of the AD-2 DAC FS by -6dBr and the sound level is identical to +4dBu from the Fireface 800 level.

Now is it effecting sound quality or dynamic range of the ADI-2 DAC FS when I lower the volume ? should I keep volume dial at 0 for maximum resolution when using external volume controller ?

What is the best advice for using ADI-2 DAC FS in studio use taking care of out level ?

Thanks, looking forward to any advice.....

Mac Studio M2 Ultra  / 14.4.1 / FF400 FF800 ADI-2 PRO FS R BE / Ableton Live 12
  • KaiS
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Re: Line Out Level Of ADI-2 DAC FS To Keep Max Resolution In Studio Use ?

If you really need exactly +4 dBu (which I kind of doubt) you could either use:

• Nominal Reference Level +1 dBu (gives +7 dBu at the XLRs) and dial back ADI-2‘s Volume by 3 dB.

• Nominal Reference Level -5 dBu (gives +1 dBu at the XLRs) and dial up ADI-2‘s Volume by 3 dB.
This setting works without distortions because ADI-2’s line outs have an additional headroom of 3 dB above full scale, meant to deal with Inter Sample Peaks - ISPs.

No problem with naturally recorded music.
ISPs appear with hot mastered (read clipped) tracks.
So if you intend to play such, better go for the 1st suggestion.


In all cases ADI-2 has such a high SNR and resolution that hardly any following amp can keep track with it anyway.

KaiS's Website

3 Reply by unpluggged (edited by unpluggged 2024-03-30 23:00:04)

  • Registered: 2023-06-30
  • Posts: 161

Re: Line Out Level Of ADI-2 DAC FS To Keep Max Resolution In Studio Use ?

Sagi.s wrote:

+4dBu is selected and as known it is Studio standard Level

+4 dBu "standard level" references to 0 VU, which is 16 dB below analog clipping. In digital realm this would closer correspond to +19 dBu or even +24 dBu ref level, which RME references at 0 dBFS.

Fireface UCX II + ARC USB > ADI-2 Pro FS R BE > Neumann KH 750 DSP + MA 1 > KH 120 A

4 Reply by KaiS (edited by KaiS 2024-03-31 00:48:11)

  • KaiS
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Re: Line Out Level Of ADI-2 DAC FS To Keep Max Resolution In Studio Use ?

Yes, for studio use digital 0 dBFS = analog +4 dBu is a very low reference level, more like “Fostex homerecording”.

I’m using 2 different 0 dBFS reference levels:
• +19 dBu for tracking with natural uncompressed dynamics.
• +10 dBu for mixing and mastering.

My meters are calibrated:
• Analog VUs: +4 dBu.
• Analog DIN Peakmeters: +10 dBu.

KaiS's Website

5 Reply by Sagi.s (edited by Sagi.s 2024-03-31 13:51:21)

  • Registered: 2009-07-26
  • Posts: 47

Re: Line Out Level Of ADI-2 DAC FS To Keep Max Resolution In Studio Use ?

• +19 dBu for tracking with natural uncompressed dynamics.

So you leave the level of ADI-2 DAC FS at 0.0dBr ?

Which is +19 dBu on the XLR output, +13 dBu auto ref plus +6 dBu at the XLR out give +19dBu ?

https://i.postimg.cc/5y08fTGJ/temp-Image-BGam4-X.avif

• +10 dBu for mixing and mastering.

So level set to auto ref and volume set to -9dBr which is +19dBu minus 9dBr gives at the XLR output +10dBu ?

https://i.postimg.cc/pLt3qM6y/temp-Imagebh-Igc-R.avif


According to RME Fireface 800

Reference        0 dBFS
Hi Gain           +19 dBu
+4 dBu           +13 dBu
-10 dBV           +2 dBV

So to achieve +4 dBu I set auto ref and dial down volume by -6dBr  which equals to +19 dBu minus 6dBr = +13 dBu and sounds by A/B the same as the Fireface 800 when set to +4 dBu

https://i.postimg.cc/Bv3qjQPC/temp-Imageq-Cu0-O3.avif

Mac Studio M2 Ultra  / 14.4.1 / FF400 FF800 ADI-2 PRO FS R BE / Ableton Live 12

6 Reply by KaiS (edited by KaiS 2024-03-31 22:07:07)

  • KaiS
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Re: Line Out Level Of ADI-2 DAC FS To Keep Max Resolution In Studio Use ?

To keep things simple, the start for each calculation is:

ADI-2 DAC XLR is +19 dBu at 0 dBFS.
With Auto Ref Level “On”, the -xx dBr Volume Dial value substracts from this +19 dBu, that all you need to know.

Ignore the reference levels shown in the display, they are just informative.

Auto Ref Level “On” switches those automatically to care for optimum SNR and resolution for each output level.


So, if you want 10 dBu:
Dial down to -9 dBr (from 19 dBu).

If you want 13 dBu:
Dial down to -6 dBr (from 19 dBu).


Remark:
dBu is an absolute voltage expressed in dB.
Volume dBr at ADI-2 is an attenuation related to it’s full scale output.

KaiS's Website

7 Reply by Sagi.s (edited by Sagi.s 2024-04-05 22:50:51)

  • Registered: 2009-07-26
  • Posts: 47

Re: Line Out Level Of ADI-2 DAC FS To Keep Max Resolution In Studio Use ?

Hi

Ok to achieve any desire dBu simple to subtract dBr from +19dBu at the XLR outputs.

I lean more to 0.0dBr with auto ref on sounds more open and reveling.


Thanks for the info and time all of you, much appreciated.

Mac Studio M2 Ultra  / 14.4.1 / FF400 FF800 ADI-2 PRO FS R BE / Ableton Live 12

8 Reply by kingstoler (edited by kingstoler 2024-04-04 02:06:46)

  • Registered: 2022-11-27
  • Posts: 11

Re: Line Out Level Of ADI-2 DAC FS To Keep Max Resolution In Studio Use ?

KaiS wrote:

To keep things simple, the start for each calculation is:

ADI-2 DAC XLR is +19 dBu at 0 dBFS.
With Auto Ref Level “On”, the -xx dBr Volume Dial value substracts from this +19 dBu, that all you need to know.

Ignore the reference levels shown in the display, they are just informative.

Auto Ref Level “On” switches those automatically to care for optimum SNR and resolution for each output level.


So, if you want 10 dBu:
Dial down to -9 dBr (from 19 dBu).

If you want 13 dBu:
Dial down to -6 dBr (from 19 dBu).


Remark:
dBu is an absolute voltage expressed in dB.
Volume dBr at ADI-2 is an attenuation related to it’s full scale output.

Thank you, excellent explanation. I've always used 0 dB with +7dBu when using RCA line out in "pure DAC mode." (Feeding the amp in 2V). Never seen it clipping. If I happen to use DSP's I'll compensate with the appropriate level. If I wanna use the RME as a volume control I set it to Auto ref. level and apply the proper amp volume. Is this the best way to do it, or should I just leave it to Auto ref. levels at all times?

  • KaiS
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Re: Line Out Level Of ADI-2 DAC FS To Keep Max Resolution In Studio Use ?

Your approach makes perfect sense.

Auto Ref Level always optimizes the SNR and resolution, and is there for convenience, specifically if variable output levels are needed like for volume control.

Choosing reference level manually would work the same way, but makes more sense if a certain fixed level is targeted.
This needs some awareness of ADI-2’s functionality for best results.

KaiS's Website