How work volume control?

riepa

Major Contributor
Joined
Feb 1, 2023
Messages
53
I understand that there is no Potentiometer built in here, you just wouldn't fit it in size.
Every electronic volume control causes sound degradation (deterioration of quality) and I can hear it here, if I reduce the volume or Vrms, I can see that the sound has degraded. It's easy to do, you turn the volume down on the Wiim and up on the amp and compare the difference.
But I don't understand one thing, what relationship do Optics have with Vrms, because it shouldn't be? Because if I reduce Vrms, the sound through Optics also decreases. This leads me to believe that there is no Vrms at all, it is virtually the same volume setting? Please someone explain, otherwise I think someone is cheating here.
 
I understand that there is no Potentiometer built in here, you just wouldn't fit it in size.
Every electronic volume control causes sound degradation (deterioration of quality) and I can hear it here, if I reduce the volume or Vrms, I can see that the sound has degraded. It's easy to do, you turn the volume down on the Wiim and up on the amp and compare the difference.
But I don't understand one thing, what relationship do Optics have with Vrms, because it shouldn't be? Because if I reduce Vrms, the sound through Optics also decreases. This leads me to believe that there is no Vrms at all, it is virtually the same volume setting? Please someone explain, otherwise I think someone is cheating here.
It just lowers the digital signal levels of the source across the full freq range.
 
It just lowers the digital signal levels of the source across the full freq range.
What the hell?
It should have no effect at all and the Vrms function should not be active at the Optics output just like Fixed volume.
 
What the hell?
It should have no effect at all and the Vrms function should not be active at the Optics output just like Fixed volume.
Vrms setting in the WiiM app is for analog output only. It's unrelated to the digital volume level.
 
Depends what do you mean by that. It changes the numbers stored as bits in the 24 bit "words" sent over spdif for example.
I also understood that cutting bits is how electronic volume controls work. Therefore, a large number of users use Optics to retrieve a clean signal without internal dac quality, interference and bit cutting.
But I still don't understand why Vrms is also shown in the interface at the Optcs output and why it works and cutting bits (to deceive people that it is Vrms)? What's the point of that? Those who came up with it were drunk?
 
I also understood that cutting bits is how electronic volume controls work. Therefore, a large number of users use Optics to retrieve a clean signal without internal dac quality, interference and bit cutting.
But I still don't understand why Vrms is also shown in the interface at the Optcs output and why it works and cutting bits (to deceive people that it is Vrms)? What's the point of that? Those who came up with it were drunk?
Not sure if I understand you correctly. Vrms level setting is for analog output only and it tells what voltage level to use as an equivalent of max volume 0 dBFS digital level. It has no impact at all on the digital output.
 
But I still don't understand why Vrms is also shown in the interface at the Optcs output and why it works and cutting bits (to deceive people that it is Vrms)?

Vrms is indeed shown on the same page as optical SPDIF output resolution, but only against “Aux out level” which refers to the analogue, not optical output. No confusion in my mind.
 
Not sure if I understand you correctly. Vrms level setting is for analog output only and it tells what voltage level to use as an equivalent of max volume 0 dBFS digital level. It has no impact at all on the digital output.
For me App Version 2.3.9.230216.7e3731, the Fixed volume settings with Vrms show up at the SPDIF setting and they all work. This should not be the case.
There should be no active Fixed Volume with Vrms at all.
 
For me App Version 2.3.9.230216.7e3731, the Fixed volume settings with Vrms show up at the SPDIF setting and they all work. This should not be the case.
There should be no active Fixed Volume with Vrms at all.
Fixed volume means that the digital volume is set at 100%, and it affects both digital and analog outputs. Alternatively speaking it means that no volume correction is added to the source.
Vrms level setting tells what voltage level to use on the analog output when converting from the digital to the analog.
Both things are independent.
 
Fixed volume means that the digital volume is set at 100%, and it affects both digital and analog outputs. Alternatively speaking it means that no volume correction is added to the source.
Vrms level setting tells what voltage level to use on the analog output when converting from the digital to the analog.
Both things are independent.
I understood that from the beginning.
It's just that you don't understand that those things that only apply to analog conversion, they don't have to be present and visible on the Optics, nor do you have to degrade the Optics signal output by bit-cutting with the wrong Vrms designation.
 
I understood that from the beginning.
It's just that you don't understand that those things that only apply to analog conversion, they don't have to be present and visible on the Optics, nor do you have to degrade the Optics signal output by bit-cutting with the wrong Vrms designation.
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Ok, I've no idea what is your problem with above settings...
 
I understood that from the beginning.
It's just that you don't understand that those things that only apply to analog conversion, they don't have to be present and visible on the Optics, nor do you have to degrade the Optics signal output by bit-cutting with the wrong Vrms designation.
You can’t “degrade the Optics signal output by bit-cutting with the wrong Vrms designation” as has been said several times, the vrms setting doesn’t impact the optical output, just the analogue output.
 
View attachment 427

Ok, I've no idea what is your problem with above settings...
What was unintuïtive to me is that fixed or variable volume also applies to the digital outputs. I assumed it was analogue only. I'd imagine if you don't know anything about how audio works you might think vrms was just another volume control.
 
I also agree that the page layout implies that fixed only applies to aux out - both the 'Fixed volume output' and 'Aux out level' (mini) / 'Line out level' (pro) options are in the same "box", and the notes advise to reduce aux out level if distortion occurs.(Says aux out even in pro screen, despite being labeled as line out.)
 
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