Why is USB audio so often preferred over AES/EBU or S/PDIF?

[Victorr_]

USB is universal. DSD up to 512, PCM up to 768 and more. Try to play such streams through SPDIF. With competent implementation, there are practically no artifacts. The influence of the interface cable is practically absent.

By the way..
I once had an Audioquest VDM-3 coaxial cable. This cable could not transmit a stream of 176.4 and 192 without continuous clicks and failures. In contrast, a thin Chinese conductor from an old VCR with yellow connectors transmitted the stream without problems.

 

[john61ct]

OK, all this pretty well clarifies why USB can be useful: it’s ubiquitous, computer-native, supports async operation, multichannel, bidirectional audio, control functions, etc etc.

Great summary!

> But what about the USB-remediation industry? If async USB is already the technically cleaner solution, why the huge ecosystem of USB cards, isolators, regenerators, reclockers, special endpoints, special cables, linear supplies, filters, and all the rest?

> USB-tweaking culture favored in "certain circles"

Snake oil infests all media types in those circles, that does not imply objective problems.

When there is a Real problem, then you take steps to fix it, isolate the loop or switch to TOSlink, whatever.

Just like employing Balanced when SE issues arise.


> proper AES/EBU and 75-ohm BNC S/PDIF are mature and boring. They have limitations, but in a normal two-channel streamer-to-DAC setup they generally just work

Is that less true for TOSlink in your opinion?

 

[Nutul]

Bla Bla Bla.
- ground Interference is in USB as is in COAX (it is physically absent in optical, of course).
- COAX and optical are limited in bandwidth: coax due to capacitance at high frequencies, and optical also due to poor materials in consumer grade cables... and instead of spending 400 bucks for a high-grade optical cable - does such thing exist? I mean, not the price... the capability of optical to do DSD, or even PCM at 384k - I prefer spending 10 in a certified USB one. You know, just like the one that perfectly transfers the data from the PC to the printer without loss or corruption).
- I2S was deigned to be internal. onboard, between-chips interface, not a cable between devices - adding RFI problems. But somebody decided otherwise, because... you know... you can, hence you will.
I really fail to understand how people nowadays can still prefer older technology, proven to be inferior on many aspects. Especially here... USB is the greatest achievement of the past 30 years in data-transfer technology, apples to every field; strangely in the audio realm it is crap...

Anyway, everybody needs to get a burn in order to understand that fire can be dangerous.
I am not the one to keep one from experiencing it, as it would be far more dangerous... I am just merely warning.

 

[johny_2000]

The primary disadvantage of SPDIF and AES compared to USB Audio Class 2 (UAC2) is that they rely on a unidirectional, source-controlled clocking mechanism that makes them highly susceptible to jitter. Conversely, USB utilizes an asynchronous data transfer mode where the DAC controls the timing loop, completely isolating the audio signal from source-generated clock timing errors.

This is particularly important for older DAC models that use synchronous data processing (without re-clocking). Modern AKM and ESS chips perform internal asynchronous resampling of all incoming data streams, making them inherently less sensitive to transmission formats—provided the data has not been completely corrupted.

Less significant drawbacks of SPDIF and AES include: sampling rate limitations (maximum 24-bit/192 kHz), lack of native DSD support, absence of bidirectional communication (for device configuration, firmware updates, status reporting, app integration, etc.), lack of multichannel audio support, and the absence of bus power (many modern DACs operate solely on power supplied via USB).

 

[klettermann]

Great summary!

> But what about the USB-remediation industry? If async USB is already the technically cleaner solution, why the huge ecosystem of USB cards, isolators, regenerators, reclockers, special endpoints, special cables, linear supplies, filters, and all the rest?

> USB-tweaking culture favored in "certain circles"
Snake oil infests all media types in those circles, that does not imply objective problems.
When there is a Real problem, then you take steps to fix it, isolate the loop or switch to TOSlink, whatever.
Just like employing Balanced when SE issues arise.

> proper AES/EBU and 75-ohm BNC S/PDIF are mature and boring. They have limitations, but in a normal two-channel streamer-to-DAC setup they generally just work
Is that less true for TOSlink in your opinion?

Yes indeed. It's quite remarkable, and even more so in said circles because of the avoidance of DSP-caused "signal
contamination." As for toslink, never used it and so have no opinion.

 

[Nutul]

The primary disadvantage of SPDIF and AES compared to USB Audio Class 2 (UAC2) is that they rely on a unidirectional, source-controlled clocking mechanism that makes them highly susceptible to jitter. Conversely, USB utilizes an asynchronous data transfer mode where the DAC controls the timing loop, completely isolating the audio signal from source-generated clock timing errors.

This is particularly important for older DAC models that use synchronous data processing (without re-clocking). Modern AKM and ESS chips perform internal asynchronous resampling of all incoming data streams, making them inherently less sensitive to transmission formats—provided the data has not been completely corrupted.

Less significant drawbacks of SPDIF and AES include: sampling rate limitations (maximum 24-bit/192 kHz), lack of native DSD support, absence of bidirectional communication (for device configuration, firmware updates, status reporting, app integration, etc.), lack of multichannel audio support, and the absence of bus power (many modern DACs operate solely on power supplied via USB).

I just didn't want (and didn't feel it would have met the meant audience understanding) to go so deep.
This should be made sticky.

 

[dartinbout]

I follow a strict protocol, for all exposed cables (and some dCs equipment internals), of liberally bathing them for 10,000 hours in the finest liquid serpent extract. Might I recommend the following:

https://www.amazon.com/Chem-X-Snake-Oil-No-Touch-Lightning/dp/B0DSXL6K17/ref=sr_1_10?crid=246C8L7EG6MFW&dib=eyJ2IjoiMSJ9.6eIqNkxrkNbbfCWjFvh0qFP3GWuBEoJHqXaMrNsXtg8u5-QTm0q5LFNc_3-ISv9Ehs0f4_QbnfTgKe_I4Yn2d9DB4sGyifiDoqxYVrdrDsGInq1M3GlDQ1o8dlLLQnZ33t_ZezXX1vlZnkVS-EEbX7QQg_6uA-eaIb1cmrGUAvkoMvGobIDuliePACNO7m_qTei-moyw3ivTs5zCyP4Z_zBPQ3xZkm5DY-v4iv8Cl_okudlLRSSKw2JLmSZiX6leD7-4Y4YnNDYMp4PUDJW2IB0NdmWa2o9NGfBT-jJ4s7k.lxjgHXvNCN-r_uM3ntytcxhFfoJFPKp3IcWQPOAP3jM&dib_tag=se&keywords=snake%2Boil&qid=1784326238&sprefix=snake%2Boil%2Caps%2C222&sr=8-10&th=1

 

[Selkirks]

I follow a strict protocol, for all exposed cables (and some dCs equipment internals), of liberally bathing them for 10,000 hours in the finest liquid serpent extract. Might I recommend the following:

https://www.amazon.com/Chem-X-Snake-Oil-No-Touch-Lightning/dp/B0DSXL6K17/ref=sr_1_10?crid=246C8L7EG6MFW&dib=eyJ2IjoiMSJ9.6eIqNkxrkNbbfCWjFvh0qFP3GWuBEoJHqXaMrNsXtg8u5-QTm0q5LFNc_3-ISv9Ehs0f4_QbnfTgKe_I4Yn2d9DB4sGyifiDoqxYVrdrDsGInq1M3GlDQ1o8dlLLQnZ33t_ZezXX1vlZnkVS-EEbX7QQg_6uA-eaIb1cmrGUAvkoMvGobIDuliePACNO7m_qTei-moyw3ivTs5zCyP4Z_zBPQ3xZkm5DY-v4iv8Cl_okudlLRSSKw2JLmSZiX6leD7-4Y4YnNDYMp4PUDJW2IB0NdmWa2o9NGfBT-jJ4s7k.lxjgHXvNCN-r_uM3ntytcxhFfoJFPKp3IcWQPOAP3jM&dib_tag=se&keywords=snake%2Boil&qid=1784326238&sprefix=snake%2Boil%2Caps%2C222&sr=8-10&th=1

Graphene? Sold.

 

[xanalog]

One of our PCs, w/an Asus Z790 ProArt Creator motherboard, features two USB-C4.0, along with two DP4 IN (+ 8k HDMI) ports.
These interfaces are for video editing, though I no longer do video work...

"Cable: must be a certified Thunderbolt/USB4 cable, not a generic USB-C cable. A certified USB4 40 Gbps cable is required, typically labeled "USB4 40 Gbps," and may also display the Thunderbolt logo if dual-compatible. These have an embedded chip that negotiates protocol — a bare USB-C charging cable will physically fit but won't carry Thunderbolt data at all, or will silently fall back to slow USB 2.0."

I give both USB and TB kudos for such SOTA speeds, using such a pos interface (that was still-born).

 

[klettermann]

Many of these are useless tweaks with, again, use cases (reclockers) in pro audio. Specifically look at some of the reviews Amir has done on the isolators sold to audiophiles - you may as well add some cable lifters. Cables can make a difference especially for long connections but otherwise rarely make a difference for audio needs.

OK, makes sense. I was a bit surprised though by the number of USB users here, though I probably shouldn't be - really a different use case than AES or spdif, though they clearly overlap. Anyway, a question to the USB users here: do you use any of the USB accessories?

 

[Victorr_]

OK, makes sense. I was a bit surprised though by the number of USB users here, though I probably shouldn't be - really a different use case than AES or spdif, though they clearly overlap. Anyway, a question to the USB users here: do you use any of the USB accessories?

My two DACs (Chord Qutest & Topping E30II Lite) do not require the use of additional filters or any accessories. Both are used with a PC, and Chord also uses other interfaces.

 

[Vincent Kars]

USB 3.x, 4.x, and so on wouldn't be any better—they would simply introduce new and additional problems.

Today USB audio is done using UAC2 (USB Audio Class 2). It set the bus in High Speed mode - 480 Mb/s regardless of its version (2/3/x)

 

[john61ct]

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

I was recently asked about merits of S/PDIF versus USB for audio DACs. It has been said that S/PDIF was designed for audio whereas USB is a computer interface. And that makes USB noisier and less desirable interface. I think most of you know my opinion on this. But just in case, I believe...

www.audiosciencereview.com

Jason @Schiit states with their "Unison" gear that USB is the better interface to use, over AES/EBU

I personally think insisting on the latter everywhere adds too much cost for me.

Sometimes even balanced analog over SE RCA does the same.

Both are really only improvements when they are Actually Needed, e.g. long distances.

TOSlink also, cheap way to get 100% galvanic isolation, but silly to chase that as a goal in itself in the absence of an Actual Problem.

But then some can afford belt & suspenders to satisfy nervosa.

I agree USB is in general the best default when available, unless another medium is specifically called for.

I do NOT think these connection media issues should dictate our choice of components, unless all else being equal.

 

[SSS]

OK, makes sense. I was a bit surprised though by the number of USB users here, though I probably shouldn't be - really a different use case than AES or spdif, though they clearly overlap. Anyway, a question to the USB users here: do you use any of the USB accessories?

Not for my regular audio setup since my PC is a laptop which has no ground connection. Then there is no ground loop. On my audio measurement setup with the QuantAsylum QA403 and a tower PC I tried the topping USB isolator, but it was not very efficient, thus I skipped it. And I use standard USB cables, nothing special and nothing expensive. When a cable is USB certified then it works for audio (which is data) and data transfer without problems. All works very good without special accessories.

 

[Aure]

This is puzzling. Why devote enormous attention to fixing USB’s apparent flaws with better outputs, isolators, regenerators, endpoints, and so on? If USB is inherently superior, why is so much remediation needed? A large USB-remediation ecosystem has developed to improve the supposedly superior interface.

A few years ago, I was still fairly new to all this and curious enough to be persuaded by an audiophile forum to buy a used Wyred 4 Sound USB reclocker, almost convinced it would improve the sound. At the time, it was one of the fashionable gadgets everyone seemed to be recommending.

https://ucarecdn.com/d65d628a-e8a7-496b-a350-ec6f18275d21/-/preview/840x630/-/setfill/ffffff/-/crop/840x630/center/

I bought it... and sold it almost immediately.

To this day, I still wonder why I was foolish enough to buy something like that in the first place.

 

[xanalog]

Anyway, a question to the USB users here: do you use any of the USB accessories?

Is this some kind of a trick question?
Would a $200 USB Dante dongle or a $5 USB3-class external SATA3 converter count?

 

[Aure]

The only USB optimization that's actually useful in my system at the moment:

I'm just not sure whether it adds more air to the sound...

 

[BookshelfBob]

Outside what are mostly psychosomatic concerns about interference and timing.

Anyone trying to distinguish between what is functionally the same exact data being fed from the source is a bit of a crazy person. There is no "color" to USB vs Toslink vs hdmi.

@Aure - if we need to get you a window AC unit, we can do that. You have powerful and wealthy friends across the Atlantic. A land of bounty where cool air is part of your God given rights. Hahahahaah

 

[Aure]

@Aure - if we need to get you a window AC unit, we can do that. You have powerful and wealthy friends across the Atlantic. A land of bounty where cool air is part of your God given rights. Hahahahaah

Haha! Thanks! Here in southern France, we still rely on old-fashioned technology: opening the windows early in the morning... then closing everything, pulling down the shutters, and living in the dark until sunset.

The only real challenge is finding the beer in the fridge.

 

[BookshelfBob]

Haha! Thanks! Here in southern France, we still rely on old-fashioned technology: opening the windows early in the morning... then closing everything, pulling down the shutters, and living in the dark until sunset.

The only real challenge is finding the beer in the fridge.

I know....You're all so resistant. Think AC is going to give you a sinus infection or something

You don't have to admit it. Just know we are here for you. We will ship it direct to your Chateau