1 Topic by bitfidelity (edited by bitfidelity 2019-05-29 21:58:46)

  • Registered: 2019-05-21
  • Posts: 22

Topic: Reference level question

My setup is ADI-2 DAC > PSI Audio A17-M. According to the studio monitors' specifications, sensitivity for 100 dB @ 1m is 0.775 V. The input sensitivity of the amps is set to 0 dB (-20 dB is the minimum).

Here are the reference level options of the DAC:

1 V (0 dBV, +2.2 dBu): Pro Ref +4 dBu, Vol -2 dB. DAC Ref +7 dBu, Vol -5 dB
0.775 V (0 dBu, -2.2 dBV): Pro Ref +4 dBu, Vol -4 dB. DAC Ref +1 dBu, Vol -1 dB
0.5 V (-3.8 dBu, -6 dBV): Pro Ref +4 dBu, Vol -8 dB. DAC Ref +1 dBu, Vol -5 dB
0.315 V (-10 dBV, -7.8 dBu): Pro Ref +4 dBu, Vol -12 dB. DAC Ref -5 dBu, Vol -3 dB

The implication here is that +1 dBu is the best choice, but do any of these settings really matter for someone who never goes anywhere near reference levels? My normal listening levels seem to hover around -40 dB to -30 dB.

I've also tried dialing my monitors' sensitivity down to -20 dB and running the unit at -5 dBu. The volume levels are still fine since I only sit a couple of feet away, but is this bad in terms of SNR?

  • ramses
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  • Registered: 2012-10-14
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Re: Reference level question

Do you hear any noise ?

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13
  • Registered: 2019-05-21
  • Posts: 22

Re: Reference level question

ramses wrote:

Do you hear any noise ?

No. My monitors have a low-level hiss regardless of what the input sensitivity is set at, so even if there was, I probably wouldn't be able to hear it.

So is it safe to say that neither the input sensitivity (A17-M) or reference level (ADI-2 DAC) settings matter for me, since both go way beyond what I need in SPL?

4 Reply by ramses (edited by ramses 2019-05-29 22:37:42)

  • ramses
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Re: Reference level question

Activate Auto Ref Level and choose a value between 0 and approx -30dB on the ADI-2 Pro.
On the display you see the reference level in use.
Choose a value that is low enough that you can comfortably control the power amp.

I use for example -13 (+7 dBu), then I can either
a) use a fix value around -50 and use the volume of ADI-2 DAC to make use of dynamic loudness or
b) choose on my Accuphase values -45 to -60

Tip: don't think to complicated, simply use the gear.
The auto ref level already chooses the proper ref level for you ...
Simply concentrate whats required on the preamp side so that the volume on the power amp side can be adjusted in a proper way.

I wouldn't worry about SNR .. its ds high these days ... for playback purposes you do not have to worry.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13