There should not be any degradation in signal from going from an iPhone to a USB DAC vs. a MacBook Pro to a USB DAC, correct?

[saveanimals]

Just 1's and 0's? Assuming everything works, playing same quality of files, uninterrupted WiFi, the sound should be identical, right? I am aware people are having some issues with the new iOS updates, but that aside, it should be the same if everything is working?

 

[onevstheworld]

Some usb powered dacs draw too much power to run from a phone.

 

[saveanimals]

Assuming that's not an issue, would you expect any difference?

 

[ProtegeManiac]

Just 1's and 0's? Assuming everything works, playing same quality of files, uninterrupted WiFi, the sound should be identical, right? I am aware people are having some issues with the new iOS updates, but that aside, it should be the same if everything is working?

As long as it works, then as far as digital signal transfer is concerned, none.

At the analogue stage, there can be depending on the power requirements. Some USB DACs might depend entirely on bus power, and while a signal comes out and there isn't any problem with the digital stream, the entirety of the DAC circuit might not be getting enough power and you end up with a low volume, distorted analogue sound output. This is more likely on the smartphone or tablet than a laptop.

That said, if there is nothing obviously wrong with the sound, then you can safely assume this isn't a problem. Sure, some DAC-HPamps might be underpowered for some headphones, but the key is that as long as the sound isn't obviously and totally effed up, then it's not from the DAC-HPamp not receiving enough bus power.

 

[bixby]

not even close, how are the ones and zeros represented? Once you have that question answered you will find that noise added to the 1/0 can and will affect sound.

Edit: While it may sound same or very close you really do not know if a 1 or 0 got played and at whether any of the dac circuitry added something akin to noise via conversion. That's why some folks can hear differences in transports

 

[saveanimals]

Can you give me a hint? That is above my pay grade, but I am genuinely curious.

 

[bixby]

voltages, here is some headbusting reading of just a few things that can affect a digital signal.

I am still trying to understand it all. This first piece illustrates in one section first hand what I experienced over the past few weeks just doing some digital eq and lowering the gain dramatically only to have digital clipping. Finally got it sorted but those ones and zeros got mangled until I did and I could nt even use one simple eq setting that I had planned.

http://www.ti.com/jp/lit/an/slyt375/slyt375.pdf

this may or may not be helpful:

https://www.head-fi.org/threads/good-music-for-choosing-a-dac.854562/page-2#post-13605436

this is a bit easier to visualize:

https://laptop-test1.blogspot.com/2013/06/measurements-do-bit-perfect-digital.html

then we have all the error points of interest by using usb as well.

Complicated stuff and amazing that 99.99 out of 100 we get repeatable good sounding music.