Topic: USB "sound level" difference when using different sources ADI 2 Pro

Hello all, I am not technical at all, so please forgive if I use the wrong wording.
I use my ADI 2 Pro only as DAC / Headphone amplifier, works a dream.
Up until now my source was a FIIO M15 connected to the ADI using a USB cable.
Unfortunately the M15 has WIFI connection problems which results in interupted streaming of music
(We live in the middle of nowhere with a"poor" mobile internet connection.)
In this set-up my maximum volume level for my headphone is -20Db
To end my problems I ordered a latest model IPAD Mini which is now  my source.

When I connect the Ipad with the same USB cable, the volume is much louder then when using the FIIO M15.
Now my ax volume is -32 Db..
How is this possible? In my limited technical understanding a USB connection just sends the 1's and 0's...
Also it seems to me, that the sound from the M15 is somewhat cleaner..

Is there anyone who could be so kind as to explain this to me?
I still have the option to return the IPAD, so if for any reason this is a worse option then the FIIO M15 I will do so.
Many thanks
Reginald

as long as you enjoy your music you are alive.

2 (edited by Muffin 2022-09-23 19:20:29)

Re: USB "sound level" difference when using different sources ADI 2 Pro

This is likely caused by volume level from your player that can reduce/increase volume digitally.

Re: USB "sound level" difference when using different sources ADI 2 Pro

Hi "Muffin" thank you for your time and reply. I forgot to mention that changing the volume on as well the Ipad as the FIIO M15 does not have an effect on the volume output of the ADI 2 PRO. I also need to mention that the files used are the same on both sources. ( copies of same audio files )
Regards
Reginald

as long as you enjoy your music you are alive.

4 (edited by ramses 2022-09-23 22:04:17)

Re: USB "sound level" difference when using different sources ADI 2 Pro

Reginald,

the playback volume should not normally change. Perhaps the player uses replay gain tags that may already be embedded in the header of your audio files, but may or may not be used depending on the player or its settings. Or you may have different volume settings in different player.

With Windows, it could also be that they used different drivers.  An ASIO driver bypasses the whole Windows sound system. But maybe you used another Windows audio driver and possibly the Windows kernel mixer was in the signal path or Windows sound extensions were enabled.

So please use the bit test, see also the manual.
Then you can play the test files in WAV format in the player and then observe if the ADI-2 DAC or Pro confirms in the display that the test was successful. Which means, that the signal path from the audio player up to the DAC (shortly before the D/A converter) is lossless.

You just have to check the details, and the manual is your friend.

BR Ramses
UFX+, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1650v4, Win10Pro22H2, Cub12Pro

5 (edited by KaiS 2022-09-24 01:44:51)

Re: USB "sound level" difference when using different sources ADI 2 Pro

reginald wrote:

...changing the volume on as well the Ipad as the FIIO M15 does not have an effect on the volume output of the ADI 2 PRO. I also need to mention that the files used are the same on both sources. ( copies of same audio files ...

I‘m using iPhone and iPad as source too, USB from CCK.
They just send the file fully original to ADI-2 Pro (RME Bit Test confirmed).

The sound is exactly the same like from CD I have connectedo to Optical in.
I often compare to find out if the streaming version is identical to the CD release - if there was a general difference this would not work.



At the moment I‘m hunting a ghost that I thought cannot be possible:
Sound-wise I‘m facing something similar to you:
a digital level reduced signal (like your FIIO does) sounds, illogically, better.


At PH 3/4 I have connected an amplifier for JJ Float QA Electrostatic headphones - the amp can be switched to drive my Raal SR1a Ribbon ‘phones too.


What happens is:
I do hear a clear difference between Hi- and Lo-Power setting.
Of course I have the 15 dB level difference digitally compensated, level is exact the same by 0.01 dB.

To compare I’m switching Setups, assigned to a button push.
I don’t have true blind A/B, as the muting/fade-in process is different in both directions.


But my expectation bias was: Sound should be the same.

What I hear: it’s not!


Hi Power sounds clearly better to me, which is the digital signal reduced by 15 dB.
(15 dB is the switching range between Hi- and Low Power).
Does this mean I do prefer the 15 dB lower resolution digital signal?


I don’t want to tell what I hear at this point, to avoid biasing others that might reproduce the test.

The test is simple:
Use two Setups, one with Hi-, the other with Lo-Power ‘phones setting, and 15 dB different Volume setting.
Activate “Load Volume with Setup”.
Compare.


@MC
Measured frequency response and level is exactly the same on both settings.
Something else changing?

I noticed the effect first by chance, completely unbiased, wondering why the sound changes.

6 (edited by ramses 2022-09-24 06:12:29)

Re: USB "sound level" difference when using different sources ADI 2 Pro

Kai, what you describe here is in my opinion an entirely different topic, or where do you see a parallel to the original question of Reginald?
This takes place at the end of the signal chain around digital volume control, with two different reference levels at the analog output.
Maybe you should have opened another thread for this so that these two different topics do not mix in this thread.

Reginald's issue / question is purely at the digital level, where it shouldn't make any difference which hardware player he connects via USB, provided the starting conditions are the same: same audio material, same digital output volume at the player, replay gain tags turned off, no EQ'ing or add-ons that manipulate the sound or add any kind of room emulation, etc.).
And USB is of course sonically neutral, pure lossless transport of digital audio data (zeroes and ones).

BR Ramses
UFX+, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1650v4, Win10Pro22H2, Cub12Pro

7 (edited by KaiS 2022-09-24 08:47:04)

Re: USB "sound level" difference when using different sources ADI 2 Pro

ramses wrote:

Kai, what you describe here is in my opinion an entirely different topic, or where do you see a parallel to the original question of Reginald?
This takes place at the end of the signal chain around digital volume control, with two different reference levels at the analog output. ...

I’m not sure about this, we both have a signal lowered in the digital domain that we hear as sounding better than the original file.

I see a coincidence on something that makes me scratch my head, and someone hearing something comparable like me.

ramses wrote:

Reginald's issue / question is purely at the digital level, where it shouldn't make any difference which hardware player he connects via USB, provided the starting conditions are the same: same audio material, same digital output volume at the player, replay gain tags turned off, no EQ'ing or add-ons that manipulate the sound or add any kind of room emulation, etc.).

Of course every other parameter needs to be kept the same to isolate the reason.

I hesitate to open a dedicated thread, to at least partly avoid to open a can of audiophile worms, so I kind of hided it here.
Maybe I do, once I can find anything valid on the measurement side.


Maybe, if you find some time, you could replicate my setting and report back what you hear.

8 (edited by ramses 2022-09-24 08:58:09)

Re: USB "sound level" difference when using different sources ADI 2 Pro

All good Kai. In the first place, I just wanted to understand exactly what you mean. I wasn't certain whether you see a connection there, or whether you just had another topic going through your head that concerns you in this context.

Currently, I still tend to think that the two things “should” have nothing to do with each other. Because of lossless audio transmission in the digital domain vs. different control of analog output stages behind the D/A converter at different ref levels.

What you describe, I would perhaps put under the rubric that the analog components might sound slightly different, when using different ref levels … Maybe something like a sweet spot of sound that matches better to your listening habits.

But I assume the differences you hear are so small that you might not be entirely sure yourself, are you? A blind test would probably be really interesting here, whether you still perceive the differences blind and then get them clearly assigned whether its A or B.

Keep it here, I made this comment only under the assumption that these are different topics, but ofc I could be wrong.

BR Ramses
UFX+, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1650v4, Win10Pro22H2, Cub12Pro

9 (edited by KaiS 2022-09-24 10:10:37)

Re: USB "sound level" difference when using different sources ADI 2 Pro

Only that the difference is not at the edge of audible, but became apparent to me without looking for it.

I have to think about a way to do blind A/B, maybe a comparison to an unchanged HP 1/2 as “neutral” reference.
Best would be to have a 2nd, identical ADI-2 Pro.

The point is: I’m sure I hear a difference, only there’s no way to locate the cause between digital and analog gain changes, and measurements don’t support there’s a difference.

Currently I’ve been stuck at this point, didn’t want to report this at all.

Now reginald comes up with such, purely in the digital domain (no ref level switching between -20 and - 32 dB).


You could really do me a favor replicating the setup and tell your listening results.
It’s just about switching two “Setups”, like described.

Re: USB "sound level" difference when using different sources ADI 2 Pro

Hello all, I hope you do not mind me scratching my head here...as said too technical is a wasted with me, I only made the observation, and wondered why a signal that is purely digital is different in sound level when the exact same files are  played from different players (FIIO M15 and 2021 Ipad mini) through USB...
Again, using the audio level settings on as well the FIIO and the iPad does not change a thing. ( When I connect my smartphone ,Huawei Pro40, through USB C to my ADI then there I can change the volume setting on the phone which is audible when playing through the ADI)

I followed Ramses's advise and ran a BIT test on both players, and they both passed.

So is it the case that as well as the FIIO M15 and the iPad Mini both have there set audio levels going out through USB?
If that is the case my question is answered.

Still leaves me scratching my head why (wonder now if this is subconsious) the FIIO sounds "cleaner" than the iPad
(my headphone is a  Hifiman HE R10P's used in LO-power)
So I do understand where Kai's confusion is coming from as well..

If it wasn't for the WIFI connection problems of the FIIO M15, I would surely stick with that.
The iPad mini is much more stable in that sense. 
Of course the problem only occurs when using a streaming service (TIDAL)
For local files there is no problem at all using the FIIO..

So to finalise does each source, in my case FIIO and iPad, have their own set audio levels that are sent through USB?

Thank you all for the replies and thoughts it is really a big help.

Cheers
Reginald

as long as you enjoy your music you are alive.

Re: USB "sound level" difference when using different sources ADI 2 Pro

reginald wrote:

I only made the observation, and wondered why a signal that is purely digital is different in sound level when the exact same files are  played from different players (FIIO M15 and 2021 Ipad mini) through USB...

I followed Ramses's advise and ran a BIT test on both players, and they both passed.

This is a part that is very strange:
if the sound level from the FIIO M15 is quieter, BitTest shouldn’t pass.
Changing digital volume changes Bits, this is what BitTest is made to detect.

Can you compare the reading of the horizontal meter, set to Pre-FX:
SETUP / Options / Display / Hor. Meter / “Pre-FX.

This way you can see what level goes into ADI-2.

Typical pop-music should go to 0 dB / full scale most of the time, same or not between FIIO or iPad ?

reginald wrote:

So is it the case that as well as the FIIO M15 and the iPad Mini both have there set audio levels going out through USB?

On iDevices this is normal, device volume doesn’t change USB.

reginald wrote:

Still leaves me scratching my head why (wonder now if this is subconsious) the FIIO sounds "cleaner" than the iPad
(my headphone is a  Hifiman HE R10P's used in LO-power)
So I do understand where Kai's confusion is coming from as well..

This, your 2nd point of concern, made me come up with my observation, as the audible result cannot be (fully) understood from the technical perspective.

Re: USB "sound level" difference when using different sources ADI 2 Pro

Hello again, Kai, thank you for your advise, I did just as you said..
Now, when playing a song that is stored on the hard drive of either FIIO or iPad the readings were similar as you suggested around o dB , the FIIO showed OVR at times for a very short period..
And now I have to start apologizing...please do not shoot the messenger.
I started playing the same track through the TIDAL app.
Result: the iPad hovered around 0 dB, the FIIO around - 6dB...
Scratch scratch, until I found MY mistake... in the TIDAL audio app on the FIIO :playback , Loudness normalization was ticked.  (this enables same volume level for all tracks)   In the Tidal app on the iPad this was NOT activated..
So there we have the culprit..
Again apologies for wasting your time...
In relation to the remark from KaiS, I did the BIT test over on both the iPad and the FIIO, paying more close attention now.
The 32Bit file passed on the FIIO (screen message clearly stating 32 passed), but seemingly not on the iPad, there the screen message very fast flicked between 16 passed and 24 passed...not showing 32 passed..
So here we go. Again sorry and I would never had found this out if not through your extensive help. THANKS

as long as you enjoy your music you are alive.