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Study: Is I²S interface better for DACs than S/PDIF or USB?

srkbear

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The explanation is simple, USB-B aren’t outputs, they are inputs. USB-A are often there to support external storage only, not for external DACs. RPi based streamers can usually output to external DAC via USB, the Zen Stream can as well, perhaps it’s built on n RPi, not sure.
But the DP5 appears to be using the USB B as an output, not as an input. Otherwise I agree with your assessment fully…
 

sarumbear

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Well I could, but I shelled out some big bucks for an Audioquest Coffee USB cable (with full acknowledgment of the controversies) and it feels a bit queasy to plug that into a cheap adapter. I’d rather stick with my Zen Stream and go without the SMSL’s graphical interface—I don’t need the DAC in the DP5 anyway.
It’s a digital connection. Why spend big bucks on it?
 

srkbear

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It’s a digital connection. Why spend big bucks on it?
*sigh* I was worried you might ask that. Well, again I know this is controversial—I just had a fairly reliable, experienced audiophile guru who had no financial stakes in the game convince me awhile back that the timing and accuracy of data transfer, not what is being transferred itself, influences the precision of data being presented to the DAC’s clock—and thus reduces errors and resulting jitter/distortion. I can’t seem to shake this explanation, please forgive me…
 

sq225917

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Well you better get shaking, all async usb dacs retime the data out of a buffer. If you can't hear drop outs the data transfer is working, there are no degrees of working, or working better. It either fails of succeeds.
 

srkbear

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Well you better get shaking, all async usb dacs retime the data out of a buffer. If you can't hear drop outs the data transfer is working, there are no degrees of working, or working better. It either fails of succeeds.
I appreciate the feedback. Tone could have been a little better. I may have some specious beliefs but I’ve given considerable thought to my setup, and I’m not a moron. I’ve heard varying opinions on this from sources I am discerning about, and I’ll happily and gratefully include yours.

Folks, please try not to scare off newcomers to this site like myself with harsh takedowns. If the goal is to share your wisdom and expertise with those less informed, you’re already at an advantage, and there’s no point in shaming those asking for honest advice—please pay it forward and teach, rather than intimidate. Thank you.
 

DonH56

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I appreciate the feedback. Tone could have been a little better. I may have some specious beliefs but I’ve given considerable thought to my setup, and I’m not a moron. I’ve heard varying opinions on this from sources I am discerning about, and I’ll happily and gratefully include yours.

Folks, please try not to scare off newcomers to this site like myself with harsh takedowns. If the goal is to share your wisdom and expertise with those less informed, you’re already at an advantage, and there’s no point in shaming those asking for honest advice—please pay it forward and teach, rather than intimidate. Thank you.

That was about as gentle as it gets, and an accurate description of the process. Ignorant does not mean stupid, nor moronic, and I am not sure how the information could have been conveyed without your taking offense.

To explain a little further, early DACs did indeed depend upon the incoming bit stream for the sampling clock, thus jitter (timing errors) on the data stream could affect the output. Even then it would take a very large amount of noise to be audible. These days, and for the past decade or three, DACs include a data buffer and internal clock so the DAC retimes the data to eliminate any dependence upon the incoming timing (jitter). They are asynchronous, meaning they operate from their own clock independent of the incoming signal. All USB cables are supposed to meet basic standards to be certified and that is all you should ever need.

HTH - Don
 

srkbear

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That was about as gentle as it gets, and an accurate description of the process. Ignorant does not mean stupid, nor moronic, and I am not sure how the information could have been conveyed without your taking offense.

To explain a little further, early DACs did indeed depend upon the incoming bit stream for the sampling clock, thus jitter (timing errors) on the data stream could affect the output. Even then it would take a very large amount of noise to be audible. These days, and for the past decade or three, DACs include a data buffer and internal clock so the DAC retimes the data to eliminate any dependence upon the incoming timing (jitter). They are asynchronous, meaning they operate from their own clock independent of the incoming signal. All USB cables are supposed to meet basic standards to be certified and that is all you should ever need.

HTH - Don
That was very helpful, thanks. I don’t think I’ve interacted with you enough for you to make any conclusions about my threshold to take offense, so I offer this introductory sentence as an example—“you better get shaking” made all the difference between his explanation and yours.

And there’s quite a difference between “ignorant”—which does suggest stupidity, and “uninformed”, which does not. I’ve just found a tendency among some folks on here to actually get testy if someone espouses some belief that they view as pseudoscience, that’s all.

Please, I don’t want to belabor this; I’ve caught on to how gentle this particular forum gets vs others, and I’m not here to ruffle feathers or change the landscape, I’m just here to share info and learn, respectfully. Peace
 
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DonH56

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That was very helpful, thanks. I don’t think I’ve interacted with you enough for you to make any conclusions about my threshold to take offense, so I offer this introductory sentence as an example—“you better get shaking” made all the difference between his explanation and yours.

And there’s quite a difference between “ignorant”—which does suggest stupidity, and “uninformed”, which does not. I’ve just found a tendency among some folks on here to actually get testy if someone espouses some belief that they view as pseudoscience, that’s all.

Please, I don’t want to belabor this; I’ve caught on to how gentle this particular forum gets vs others, and I’m not here to ruffle feathers or change the landscape, I’m just here to share info and learn, respectfully. Peace
You said: "I can’t seem to shake this explanation, please forgive me…" and @sq225917 started with "Well you better get shaking" so it seemed to me a direct play on your response. I might have done the same thing out of a quirky sense of humor had I been first to respond. I really doubt anything more was meant by it, though "you'd better get shaking" is something I heard a lot in my younger days, mainly when I was seeking to avoid work. :)

Ignorance to me means a lack of knowledge, not a lack of ability (or desire) to learn. Stupid implies both.

This is not the most gentle of places but others tend to be much worse IME. As a conversational medium the Internet sucks IMO. "Nobody can see you smile on the 'net." Bear in mind that most questions have been asked a hundred times before so sometimes it's easy to get a bit jaded and respond curtly. Please don't take offense.

Onwards - Don
 

gvl

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But the DP5 appears to be using the USB B as an output, not as an input. Otherwise I agree with your assessment fully…

That would be a very silly thing of them to do. I saw some pictures online indicating USB-B is an output but that is wrong. According to the manual you use USB-A to connect an external DAC. The last "note" is rather ominous though but I can't parse it with a good amount of certainty. I don't know why would anyone want to use a DP5 and another DAC, the DP5 is not too good of a streamer but it has a pretty good DAC in it already, so why bother. If you have a good DAC just get an RPi based solution or even Chromecast Audio and be done.

1638077797914.png
 

sarumbear

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*sigh* I was worried you might ask that. Well, again I know this is controversial—I just had a fairly reliable, experienced audiophile guru who had no financial stakes in the game convince me awhile back that the timing and accuracy of data transfer, not what is being transferred itself, influences the precision of data being presented to the DAC’s clock—and thus reduces errors and resulting jitter/distortion. I can’t seem to shake this explanation, please forgive me…
It is your life and if you feel happy with it then go ahead, but I still want to know what is it he said that convinced you? What was it other than "trust me"?
 

sarumbear

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srkbear

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You said: "I can’t seem to shake this explanation, please forgive me…" and @sq225917 started with "Well you better get shaking" so it seemed to me a direct play on your response. I might have done the same thing out of a quirky sense of humor had I been first to respond. I really doubt anything more was meant by it, though "you'd better get shaking" is something I heard a lot in my younger days, mainly when I was seeking to avoid work. :)

Ignorance to me means a lack of knowledge, not a lack of ability (or desire) to learn. Stupid implies both.

This is not the most gentle of places but others tend to be much worse IME. As a conversational medium the Internet sucks IMO. "Nobody can see you smile on the 'net." Bear in mind that most questions have been asked a hundred times before so sometimes it's easy to get a bit jaded and respond curtly. Please don't take offense.

Onwards - Don
With that lovely response, I assure you I will not, and thank you!
 

srkbear

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That would be a very silly thing of them to do. I saw some pictures online indicating USB-B is an output but that is wrong. According to the manual you use USB-A to connect an external DAC. The last "note" is rather ominous though but I can't parse it with a good amount of certainty. I don't know why would anyone want to use a DP5 and another DAC, the DP5 is not too good of a streamer but it has a pretty good DAC in it already, so why bother. If you have a good DAC just get an RPi based solution or even Chromecast Audio and be done.

View attachment 168519
You’re right—I tried plugging it in to the USB-A port and it found my DAC. You’re right again—I don’t know why anyone would want to pair this thing with an external DAC, particularly with my D90se or my x26 pro. Roon only recognizes it via Airplay and it nearly blows out my cans every time I switch tracks—I’ve got it packed up and can’t send it back soon enough. I really didn’t want a streamer with a DAC; I wanted a streamer only—but I heard crappy things about the SD-9. Turns out the DP5 has the same problems.

I love the sound and versatility of my Zen Stream, which is indeed a Volumio-based modified RPI setup—i just wish it had a better GUI (it has none). I have my system on my nightstand and don’t want to use a PC or phone as a signal source. I have a Cambridge Audio cxn v2 and a Cocktail Audio n25 on the way to test—if you know of any other good streamers under $1,500 I’d welcome the input.
 
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srkbear

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It is your life and if you feel happy with it then go ahead, but I still want to know what is it he said that convinced you? What was it other than "trust me"?
Nah—he was a very trusted resource otherwise and my guru helping me build my guitar amps; he’s a top notch luthier and a whiz with amp electronics. He gave the explanation I’ve already provided and I likely fell into the placebo chasm—and this was a long time ago. I had spent so much on quality components for my system that I didn’t sweat $150 on a cable, especially since I was already buying high quality XLR interconnects at the same time.

Now if you’re gonna tell me that cheap XLR cables do the trick too I’m gonna cut my head off my neck.
 
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BDWoody

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Now if you’re gonna tell me that cheap XLR cables do the trick too I’m gonna cut my head off my neck.

I don't know how to break it to you...;)

Step back from the guillotine...
 
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srkbear

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I don't know how to break it to you...;)
Oh, come on! Next you’re gonna tell me headphone cables don’t matter either too? Now with that I DO hear a clear difference and my ears are not virginal—I’ve been an obsessive musician my whole life. You’re kidding me now, right? :)
 

BDWoody

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Oh, come on! Next you’re gonna tell me headphone cables don’t matter either too? Now with that I DO hear a clear difference and my ears are not virginal—I’ve been an obsessive musician my whole life. You’re kidding me now, right? :)

It isn't that they don't matter, it's that they don't have to be expensive. The cable side of this business, both analog and digital, has to be the worst offenders in terms of taking advantage of the ignorance of buyers.
 

BDWoody

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By the way, how did you get “Chief Cat Herder” under your avatar? My cats are complaining that I don’t have that now…

That's my prize for being one of our two moderators... Seemed most appropriate for this place!
 
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