[Allanmarcus]

From the Jotunheim thread, post #630
 

Well it seems that I must retract what I said yesterday about the USB versus Toslink cables/connections from my iMac to the Modi MB.  I have been listening to various music all day with the Toslink and occasionally flipping to the USB connection and I must say that the Toslink connection definitely sounds more expansive with better bass punch.  Mind you it's not night and day different but audibly noticeable if a fair amount of comparison time is taken.

 
My question, now is this possible? Is this possible? I realize digital audio is more than 1's and 0's, timing and noise can be a factor, but how can the digital transport change the FR of the output? Can it?

 

[madwolfa]

Not possible.

 

[Ancipital]

I'm not sure, random Macs are famous for ropy USB implementation, but I wouldn't expect anything "inside" the signal, as that's not how it works- jitter and dropouts, sure, but not that. Could be confirmation/expectation bias or aliens.

 

[GRUMPYOLDGUY]

No. Not possible.

The digital values are the digital values. Those values are not modified by the medium which carries them in the manner you're talking about.

Ask the original poster to do a blind test.

Sent from my E5803 using a highly trained, special forces carrier pigeon

 

[Allanmarcus]

No. Not possible.

The digital values are the digital values. Those values are not modified by the medium which carries them in the manner you're talking about.

Ask the original poster to do a blind test.

Sent from my E5803 using a highly trained, special forces carrier pigeon

I would love to ask them to do a blind test, but them's fighting' words in audiophila, but heavily frowned upon anywhere but the sane forum (er, Sound Science) 

 

[castleofargh]

I can think of a few reasons why 2 digital input may sound different in some cases, but I don't think looking into objective reasons to validate an empty claim is very constructive. I suggest to simply ignore anything that talks about easily measurable differences while not showing said measurements. if the guy desires to be taken seriously, he will provide frequency responses or a short recording of a song with both inputs. if he can't be bothered to do it, then he mustn't care much and we should care even less.

 

[gregorio]

  I realize digital audio is more than 1's and 0's, timing and noise can be a factor, but how can the digital transport change the FR of the output? Can it?

 
Digital audio is NOT more than 1's and 0's, by definition. The timing of those 1's and 0's can, under certain extreme situations, have an effect but noise does not, again except in extreme situations.
 

  My question, now is this possible? Is this possible?

 
It is theoretically possible. If for example the USB were so badly implemented that very large amounts of jitter were introduced, this could result in phase issues between left and right channels which could result in the stereo image being affected and some frequency cancellation in lower frequencies, giving a thinner, less bass sound. I have experienced and successfully blind tested this myself. However, that was with a first generation multi-channel 24bit pro ADC/DAC twenty years ago. I would not expect that amount of jitter in any DAC designed in the last 5 or 10 years, even relatively cheap consumer DACs. Clocking is one area of digital audio which has improved significantly in the last 15 years and can be done now both very accurately and very cheaply. The likelihood of an audible issue is extremely unlikely, barring an incompetent design flaw and of course for there to be an an audible difference between the USB and Toslink inputs, the unit would have to have competent handling of the Toslink input AND incompetent handling of the USB input.
 
All things considered, what was posted is possible but extremely unlikely. I would not believe it without some decent blind testing and even if it were proven in an individual case, it certainly would not be applicable to the vast majority.
 
G

 

[PurpleAngel]

  From the Jotunheim thread, post #630
 
My question, now is this possible? Is this possible? I realize digital audio is more than 1's and 0's, timing and noise can be a factor, but how can the digital transport change the FR of the output? Can it?

 
My two cents and best guess.
The program(s) the Mac uses might use different audio settings, for the USB connection output and the Toslink optical connection output.
But this just a big guess.

 

[Ancipital]

  I can think of a few reasons why 2 digital input may sound different in some cases,

 
Obviously there is the potential for ground noise, and general induced RFI, but I really don't think that's what we're talking about here. It sounds more like Audiomagination(tm) caused by expectation bias. It sounds like one of those cases where a blind ABX would actually help as a first step. Find out if there is really anything there before trying to work out what it is...

 

[Allanmarcus]

@Tuneslover 
Just out of curiosity, what player are you using (iTunes?) and are the settings for the output set the same in Audio MIDI Setup?

 

[Tuneslover]

@Tuneslover
 
Just out of curiosity, what player are you using (iTunes?) and are the settings for the output set the same in Audio MIDI Setup?

Yes I am using iTunes. I'm not at my computer at the moment but I need to manually go into the iMac's System Settings >Sound and switch the audio from the previous Schiit USB selection to the Schiit Toslink selection. Then change the input selection on the Schiit DAC from USB to Toslink. A bit cumbersome but doable.

 

[Allanmarcus]

 

@Tuneslover
 
Just out of curiosity, what player are you using (iTunes?) and are the settings for the output set the same in Audio MIDI Setup?

Yes I am using iTunes. I'm not at my computer at the moment but I need to manually go into the iMac's System Settings >Sound and switch the audio from the previous Schiit USB selection to the Schiit Toslink selection. Then change the input selection on the Schiit DAC from USB to Toslink. A bit cumbersome but doable.

You can select "Show Volume in Menu Bar" in the sound prefs, then the volume icon will appear in the menu bar near the clock. If you opiton-click on the volume icon in the menu bar, you can quickly change input and output.
 
If you open /Applications/Utilities/Audio Midi Setup you can click on each output interface and see how it is set. See if the USB output and the Toslink output are set the same.

 

[Tuneslover]

You can select "Show Volume in Menu Bar" in the sound prefs, then the volume icon will appear in the menu bar near the clock. If you opiton-click on the volume icon in the menu bar, you can quickly change input and output.

If you open /Applications/Utilities/Audio Midi Setup you can click on each output interface and see how it is set. See if the USB output and the Toslink output are set the same.

Thanks for the information. I will try it when I get home tonight.

 

[DKMTech]

All digital transports sound different. There's no way to transfer 0's and 1's without first turning them into an analog signal. The cables do matter and so does the signal being fed into them, aka your transport, whether that be a computer or a CD transport, etc. Specifically, the USB input of the DAC or SPDIF converter you are using makes a big difference. The Schiit gear is incredible for the money but they do not use the best USB input receivers on the market and I have experienced the same type of results that you have. Specifically, using AES/ EBU instead of USB and getting better results. It all depends upon the equipment you are using and the type of cables in each scenario. Everything matters and all 0's and 1's are not created equally.

 

[Ancipital]

 
All digital transports sound different. There's no way to transfer 0's and 1's without first turning them into an analog signal. The cables do matter and so does the signal being fed into them, aka your transport, whether that be a computer or a CD transport, etc. Specifically, the USB input of the DAC or SPDIF converter you are using makes a big difference. The Schiit gear is incredible for the money but they do not use the best USB input receivers on the market and I have experienced the same type of results that you have. Specifically, using AES/ EBU instead of USB and getting better results. It all depends upon the equipment you are using and the type of cables in each scenario. Everything matters and all 0's and 1's are not created equally.

 
You're that magic file copying guy in disguise, aren't you?