1 Topic by superbaka (edited by superbaka 2021-04-17 00:26:58)

  • Registered: 2020-02-15
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Topic: Output gain - which setting?

This has been talked about in bits and pieces before, but I want to go back to basics :

I am connecting the UFX+ to a Class D amp with balanced XLR. (Ch 1+2).

All 4 output settings (-10, +4, Hi Gain, +24) will give me more than enough volume and I must attenuate the output fader to listen at comfortable levels.

Which output setting do I choose for the optimum sound and amp behavior? All 4, with corresponding attenuation, will yield very slightly different sonic results. (And I can't tell if this different sonic behavior is occurring in the DAC or the amp.)

thank you

2 Reply by MC

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Re: Output gain - which setting?

If the Class D amp is so overly sensitive then I would use the +4 dBu output setting and add a simple, switchable passive attenuator (XLR) as described here:

https://forum.rme-audio.de/viewtopic.php?id=25399

That will ensure no surprise volume peaks and optimizes SNR as much as possible.

Regards
Matthias Carstens
RME

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Re: Output gain - which setting?

I can confirm this arrangement. I am using +4 dBu and the JBL Nanopatch passive attenuator. Works well.

UFX+; MADIfaceUSB; Startech active USB3 cable; Sonnet Allegro Pro adapter; Win11x64
  • Registered: 2020-02-15
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Re: Output gain - which setting?

Thanks.

Which of these output stages has the best SN?

I thought they are like ADI-2 where they each optimize SN, but seems from reading the other thread that is not the case?



MC wrote:

If the Class D amp is so overly sensitive then I would use the +4 dBu output setting and add a simple, switchable passive attenuator (XLR) as described here:

https://forum.rme-audio.de/viewtopic.php?id=25399

That will ensure no surprise volume peaks and optimizes SNR as much as possible.

5 Reply by MC

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Re: Output gain - which setting?

Even the ADIs do not maintain the full (!) SNR at the lowest ref level. At these you run into basic problems like the base noise of the electronics driving the output, limiting the max available SNR. The setting as such is still useful as it limits max volume/level. But when an attenuator (after the final noise source) is used anyway then the better SNR is kept by not using the lowest ref level. That is the case with the ADIs as well.

Regards
Matthias Carstens
RME

MC's Website

6 Reply by superbaka (edited by superbaka 2021-04-21 18:07:11)

  • Registered: 2020-02-15
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Re: Output gain - which setting?

(Lowest ref level, you mean -10?)
...
So if we assume there is no volume problem with speakers/etc attached to the UFX and we are only talking about the quality of the signal inside UFX, which is the optimum setting for output on the Mains 1+2?

-10
+4
Hi Gain
+24

Is there one that is inherently the best to use?

I realize one reason its confusing is because I don't know the full signal path inside UFX.
thanks again

7 Reply by MC

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Re: Output gain - which setting?

+4 (+13 dBu) and High Gain (+19 dBu) have identical performance. +24 might introduce various issues when used with attenuators, so don't.

Regards
Matthias Carstens
RME

MC's Website