1 Topic by rmeuserr (edited by rmeuserr 2013-03-25 14:21:18)

  • Registered: 2009-10-21
  • Posts: 12

Topic: Changing UC/ADI-8 from '+4dBu' to 'Lo Gain'= tiny sound degradation?

Hello fellow RME-users and RME support team,

Trying to integrate my Avalon 747 and work comfortably with its 'very particularly' working compressor and gainstages  I always find myself in the situation that I have my RME UC and also ADI-8 AE input close to clipping at the input '+4dBu' setting.
So I switched to 'lo Gain' input but I have the feeling that this changes the sound itself a bit for the worse/some degradation or lets say the sound changes a bit.
Can you confirm this?

Question:
1) Input setting: changing from '+4dBu' and 'lo Gain'
Does switching the input setting on my RME converters from '+4' -> 'lo Gain' change the sound itself in any slightest way?

I had the impression that it does and the 'lo Gain' setting sounds a tiny bit duller while the '+4' setting was 'sweeter and breathing more freely'.
Should 'Lo Gain not rather have sounded 'more relaxed and free' since I increased the headroom for this hot Avalon output signal?
Can this be due to some form of 'padding' in the RME converters to get more headroom at 'lo Gain'?
Which RME setting equals 'purest' audio?
Is there such a thing as a sweetspot at a RME '+4dBu' setting and another sweetspot for the 'Lo Gain' position that should be taken into account? (Of course nothing is clipping in my example)

Or do they actuall sound exactly the same at both settings and I rather imagine things?


2) another Output setting question: changing from '+4dBu' to 'Hi Gain'
Will changing the output setting from '+4dBu' to 'Hi Gain' not change the sound slightly too as RME converters will have to amplify the signal?
If yes, which setting is the one with the 'cleanest/unaltered' output?

3) If yes, is this changed sound/degradation the same for both RME converters UC and ADI-8 AE ...or do they use different components to pad and amplify signals.
Which one delivers better as regards this on Lo Gain input and Hi Gain output: Fireface UC or ADI-8 AE?
(My feeling is that ADI-8 AE converters are a bit superior to those of the Fireface UC, right?)

Thanks for your help and some clarification!

regards,Rak

2 Reply by Runepune (edited by Runepune 2013-03-23 18:34:01)

  • Registered: 2011-12-16
  • Posts: 59

Re: Changing UC/ADI-8 from '+4dBu' to 'Lo Gain'= tiny sound degradation?

I wouldn't think there's much of a difference, if any... That said, I'm curious why RME chose to do it this way, and how it's done....what's the benefit over just having 15 dB headroom on the +4 dBU setting?

3 Reply by rmeuserr (edited by rmeuserr 2013-03-25 14:19:26)

  • Registered: 2009-10-21
  • Posts: 12

Re: Changing UC/ADI-8 from '+4dBu' to 'Lo Gain'= tiny sound degradation?

Edited post!

Hi,

Runepune wrote:

I wouldn't think there's much of a difference, if any...

That's the big question: slight difference for the worse or not any at all? hmm If there is padding involved than it might be changing the sound in some way.
Is that soundchange really audible? ...hmmm I have the feeling it is.


Runepune wrote:

That said, I'm curious why RME chose to do it this way, and how it's done....what's the benefit over just having 15 dB headroom on the +4 dBU setting?

Edited: good questions. 

Thanks and regards,Rak

4 Reply by Runepune (edited by Runepune 2013-03-25 16:56:08)

  • Registered: 2011-12-16
  • Posts: 59

Re: Changing UC/ADI-8 from '+4dBu' to 'Lo Gain'= tiny sound degradation?

rmeuserr wrote:

1) I think it is just 13dB headroom at +4dBu setting and 19dB headroom at 'lo Gain' setting.

That is max output. The reference is +4 dBU, so on that setting the headroom is 9 dB. I assumed +4 dBU was also the reference on the Lo Gain setting, but I dunno smile

They also chose to do it this way/offer these options so that if you have for example a weak signal going into the RME inputs at +4dBu -which would only use say 14 bits- you can easily change to -10dBv which then will translate into using a much higher bit count than just those 14bits.

I understand the -10 dBv and +4 dBU setting, because those are the two standard/reference levels most all equipment work at. I'm a bit curious about the reason for the last one though! smile

Just get the RMS of your signal to stay around +4 dBU on your "+4 dBU gear" (e.g. the Avalon), and set the RME to handle the peaks, +4 dBU or Lo Gain. I've left mine at Lo Gain, but I need to check if there's any perceivable difference...

5 Reply by rmeuserr (edited by rmeuserr 2013-03-24 22:18:02)

  • Registered: 2009-10-21
  • Posts: 12

Re: Changing UC/ADI-8 from '+4dBu' to 'Lo Gain'= tiny sound degradation?

Runepune wrote:

...I've left mine at Lo Gain, but I need to check if there's any perceivable difference...

Yes, please do so... it would be really nice to hear your findings  and also get some information from the RME support team on that.

Thanks and regards,Rak

6 Reply by rmeuserr (edited by rmeuserr 2013-03-24 22:38:07)

  • Registered: 2009-10-21
  • Posts: 12

Re: Changing UC/ADI-8 from '+4dBu' to 'Lo Gain'= tiny sound degradation?

Runepune wrote:

...
That is max input. The reference is +4 dBU, so on that setting the headroom is 9 dB. I assumed +4 dBU was also the reference on the Lo Gain setting, but I dunno smile
...
I understand the -10 dBv and +4 dBU setting, because those are the two standard/reference levels most all equipment work at. I'm a bit curious about the reason for the last one though! smile
...

Hi Runepune,

I'm sorry, you are right of course and now I understand your question too, therefore I edited my original post as not to confuse with wrong statements.
And yes, it says in the FF UC manual that the reference for the Lo Gain setting is +4dBu as well.

regards,Rak