Battle of S/PDIF vs USB: which is better?

[DonH56]

Satire my friend.....hence the "Z".....

(Full disclosure: degree in Applied Physics, worked on signal processing for x-ray laser research projects in upper division lab work)

Oops, sorry, hard to tell on the monitor. I'm a hairy-knuckled engineer, though been around a few physicists (most famous probably Feinstein, only very briefly, what a character!) Designed a few VCSEL drivers and dealt with some optical laser systems but never got very deep into them.

Back on-topic, more or less, regarding the previous jitter comment: The original AES spec allowed a lot of jitter (like 40-50 ns pp) but I thought it was knocked down to 1 ns or 0.1 ns when consumer DACs started using the recovered clock (unlike many pro systems). Now DACs typically decouple their clock from the datastream but I am not sure the AES (S/PDIF, TOSLINK) jitter spec -- should know, spaced it, long day (back hurts from shoveling and it's affecting my brain tonight).

 

[watchnerd]

Oops, sorry, hard to tell on the monitor. I'm a hairy-knuckled engineer, though been around a few physicists (most famous probably Feinstein, only very briefly, what a character!) Designed a few VCSEL drivers and dealt with some optical laser systems but never got very deep into them.

Back on-topic, more or less, regarding the previous jitter comment: The original AES spec allowed a lot of jitter (like 40-50 ns pp) but I thought it was knocked down to 1 ns or 0.1 ns when consumer DACs started using the recovered clock (unlike many pro systems). Now DACs typically decouple their clock from the datastream but I am not sure the AES (S/PDIF, TOSLINK) jitter spec -- should know, spaced it, long day (back hurts from shoveling and it's affecting my brain tonight).

I'd actually love to see a 21st century asynchronous optical based digital audio connector to get "the best of both worlds" between optical benefits over distance plus asynchronous clocking benefits.

Or, more realistically....

Just implement Audinate / Dante in consumer products.

I'm always a bit surprised no high end maker adopted it.

And I'd love to see @amirm test one of these:

 

[DonH56]

The new Harman processors will include Dante.

 

[watchnerd]

The new Harman processors will include Dante.

Really?

Which brands? The pro ones?

Or the Levinson products?

 

[DonH56]

The JBL series, not sure which ones. I think SDP-55 and the related AVR, both including Dirac Live; the SDP-75 and (I think) SDP-65 are Trinnov-based and do not include Dante AFAIK. @amirm probably knows. These are expensive, though, something like $6k for the SDP-55 IIRC.

 

[Mark Lawless]

I'm having a discussion on FB, recently I took my Topping D30 off of optical and attached my laptop to the DAC using USB. Suddenly I was hearing more detail and tighter focus on the soundstage. The music itself seemed cleaner. I remember one song specifically with a horn in it and the horn was much better. My FB friend says this is not possible and he actually uses this article to argue that. I am using some B&W802Ds and a Krell EV302 Amp. This gear is pretty revealing and so I'm wondering would you also say I'm imagining things. I assure you what I am hearing is not a slight improvement over the Optical. Perhaps there's something else at play here that I'm missing.

 

[Mark Lawless]

That shouldn't be, though Amir found some issues with the D30's handling of S/PDIF data. I'm not sure I believe the issues to be audible but short of a DBT of the two impossible to say for sure.

What is a DBT?

 

[Blumlein 88]

What is a DBT?

Double blind testing.

If you still hear differences when you didn't know whether optical or USB is being used then they are real. If you know what you are listening to there are many ways our brains play tricks on us.

Looks like you are a new member. So let me welcome you here.

 

[Soniclife]

Perhaps there's something else at play here that I'm missing.

Have you had a good look at the 2 sound card configurations? I suspect the windows mixer is in use with one, but exclusive mode on the other.

 

[Sal1950]

What is a DBT?

Double blind testing.

If you still hear differences when you didn't know whether optical or USB is being used then they are real. If you know what you are listening to there are many ways our brains play tricks on us.

Looks like you are a new member. So let me welcome you here.

Yes and most importantly the level of the two sources must be matched to within a tenth of a db. Even the slightest difference in volume level will change the way you perceive the sound in many ways.
Also Welcome to ASR

 

[Michiel de Ruyter]

I want to add my experience with the USB-interface. I have been using a USB-soundcard (Soundblaster X-Fi Surround 5.1 Pro) since the mid-00's, I have used two headphones on it: an HD598 (which was rebranded as the HD599) and an HD700, both from Sennheiser.. A recurring problem which I always had was arbitrary crackling noise. I can only describe it as similar to what you might hear with an old LP but much stronger, or similar to when you burn wood in fire and hear a crackling sound. Here the interesting thing: it doesn't matter which USB-port you use, it can come any time on any port and sometimes switching the port helps, sometimes it doesn't, sometimes leaving it on the same port and booting the computer again solves the problem. i have had this on two different systems, an Acer prebuild and a computer which I assembled myself (3700X, X570 Gigabyte Elite). I have used multiple operating systems: Windows7, Windows10 and several Linux distros. Some operating systems (W7) have this worse than others (Linux distros) but on all operating systems you hear it in some way. On Linux distros it seems to be limited to when you change the volume by moving the slider with the mouse (not when you use a keyboard-button to change the volume), on Windows7 I had it all the time when just watching a video and it could get loud. I agree with the topicstarter that we should look at the measured data but I also believe that maybe not everything which is relevant gets measured. Maybe the USB-interface becomes a problem when the same USB-hub (which several ports are connected to) is being used for other data too (keyboard, mouse...). Maybe the USB-interface becomes a problem when there is too much electromagnetic interference from the components on the PCB (like a motherboard). I don't have the answers, I can only share my experience that I had a lot of problems with crackling noise which was related to the USB-interface given that it often disappeared or changed by simply plugging it into another USB-port.

 

[Michiel de Ruyter]

In the meantime I can update about my experiences. Unfortunately my soundcard still needs USB for the power and that power comes from the computer, only the data goes via S/PDIF. Still crackling noises. The weird thing, after every boot it is a problem, when I change it to another USB-slot it goes away. It clearly is the power via USB which causes the problem, not the data-transfer via USB. I would guess that a good external USB power supply would solve the problem but I haven't tried it out.

 

[Kal Rubinson]

I want to add my experience with the USB-interface. I have been using a USB-soundcard (Soundblaster X-Fi Surround 5.1 Pro) since the mid-00's, I have used two headphones on it: an HD598 (which was rebranded as the HD599) and an HD700, both from Sennheiser.. A recurring problem which I always had was arbitrary crackling noise. I can only describe it as similar to what you might hear with an old LP but much stronger, or similar to when you burn wood in fire and hear a crackling sound. ......................................................... Maybe the USB-interface becomes a problem when the same USB-hub (which several ports are connected to) is being used for other data too (keyboard, mouse...). Maybe the USB-interface becomes a problem when there is too much electromagnetic interference from the components on the PCB (like a motherboard). I don't have the answers, I can only share my experience that I had a lot of problems with crackling noise which was related to the USB-interface given that it often disappeared or changed by simply plugging it into another USB-port.

This is not a USB audio problem. This is a system issue and the defect may be particular to your home setup. I have been using USB for audio for years with several computers, Win and Mac, and never had such experiences, even with the ocassional use of a USB-hub. Does your audio processing have higher system priority than your other data?

 

[Michiel de Ruyter]

I hadn't tried it yet. That is a good idea, it might work. I had this problem with two systems, it looks like it has to do with the soundcard.

 

[Scriba]

is it a myth that surround sounds will transfer better with S/PDIF than USB? some people say yes, other say both is digital so it doesn't matter

 

[ReaderZ]

Well, didn't Amirm at one point after making this thread had to go to s/pdif since usb of his gaming pc give way too much noise?

 

[Fitzcaraldo215]

Well, didn't Amirm at one point after making this thread had to go to s/pdif since usb of his gaming pc give way too much noise?

What? I missed it, and I just recently reread them all. You are in error, to put it mildly, based on the technical measurements which Amir has taken. There is nothing to refute Amir’s initial technical opinion vs. USB over spdif.

 

[ReaderZ]

What? I missed it, and I just recently reread them all. You are in error, to put it mildly, based on the technical measurements which Amir has taken. There is nothing to refute Amir’s initial technical opinion vs. USB over spdif.

No, rather pointing out in certain situation S/PDIF has it's value and advantage over USB. When these situation happen, the advantage of S/PDIF over USB is overwhelming because you get very audio-able and sometimes unbearable noise form USB, unlike USB's advantage over S/PDIF in most situation will be very very hard to detect by human ear.

Also here is the quote from another thread.

https://www.audiosciencereview.com/forum/index.php?threads/singxer-uip-1-usb-isolator-review.10982/

"Ever since I received my new custom built gaming PC for my main workstation, the DX3 Pro which I use as daily DAC and headphone amp, has been produces pretty bad noises when no music is playing. It got so bad that I disconnected the USB and went with Toslink optical from the motherboard. That took care of the problem nicely. "

 

[Fitzcaraldo215]

No, rather pointing out in certain situation S/PDIF has it's value and advantage over USB. When these situation happen, the advantage of S/PDIF over USB is overwhelming because you get very audio-able and sometimes unbearable noise form USB, unlike USB's advantage over S/PDIF in most situation will be very very hard to detect by human ear.

Also here is the quote from another thread.

https://www.audiosciencereview.com/forum/index.php?threads/singxer-uip-1-usb-isolator-review.10982/

"Ever since I received my new custom built gaming PC for my main workstation, the DX3 Pro which I use as daily DAC and headphone amp, has been produces pretty bad noises when no music is playing. It got so bad that I disconnected the USB and went with Toslink optical from the motherboard. That took care of the problem nicely. "

Yes, that refers to the specific case of a convoluted, cheap Singxer hooked up to a god knows what computer. Yes, ground loops and other things are unpredictable, although not that hard to circumvent with patience.

But, do you have a general recommendation for equipment which do not have excess noise upon the based their inteconnection architecure? I for one should think that they should stay with USB, besides the numerous advantages in Amirs’ postings.

 

[ReaderZ]

Yes, that refers to the specific case of a convoluted, cheap Singxer hooked up to a god knows what computer. Yes, ground loops and other things are unpredictable, although not that hard to circumvent with patience.

But, do you have a general recommendation for equipment which do not have excess noise upon the based their inteconnection architecure? I for one should think that they should stay with USB, besides the numerous advantages in Amirs’ postings.

I am using USB on my DX7 pro. The point is you might not want a USB only DAC, having S/PDIF is an important plan B. Unless you get something like Singxer SDA-2 DAC's high end version which has galvanic isolation on USB input to deal with these issues. (It also have optical in as well.)