Why Do Different USB Cables Sound Different

[ack]

I recently had an email conversation with Serguei Timachev from Stealth Audio who provided a cogent (at least for me) explanation of why USB cables can and do sound different. Thought I'd share it below. Interesting info.

"The common (incompetent) logic AGAINST ANY premium USB cables usually is that in digital signal transmission the data errors get corrected (and the incomplete or distorted data packets get re-sent). For some reason folks do not know (or do not realize) that music is being transmitted as a STREAM, without any correction, and thus gets distorted (more or less) in a similar fashion as analog signals.

On top of that, a lot of people do not know that S/PDIF protocol for digital audio is, in fact, an ANALOG protocol: digital signal, consisting of “ones” and “zeros” gets converted into a corresponding analog signal, then this ANALOG signal gets transmitted via a “digital” transmission line (75 Ohms characteristic impedance at BOTH ends), and then the receiver chip once again converts this analog signal into digital. Any distortion of this analog signal CHANGES “ones” and “zeros” in the received signal, after the second conversion at the receiver. I.E. the received “ones” and “zeros” digital signal after the S/PDIF transmission is NOT exactly the same as the signal that has been sent. And THIS IS why digital cables do make a sonic difference."

Tell him, Nonsense. He needs to look at jitter and/or noise. Only under extremely poor conditions will there be data loss.

 

[Empirical Audio]

I recently had an email conversation with Serguei Timachev from Stealth Audio who provided a cogent (at least for me) explanation of why USB cables can and do sound different. Thought I'd share it below. Interesting info.

"The common (incompetent) logic AGAINST ANY premium USB cables usually is that in digital signal transmission the data errors get corrected (and the incomplete or distorted data packets get re-sent). For some reason folks do not know (or do not realize) that music is being transmitted as a STREAM, without any correction, and thus gets distorted (more or less) in a similar fashion as analog signals.

On top of that, a lot of people do not know that S/PDIF protocol for digital audio is, in fact, an ANALOG protocol: digital signal, consisting of “ones” and “zeros” gets converted into a corresponding analog signal, then this ANALOG signal gets transmitted via a “digital” transmission line (75 Ohms characteristic impedance at BOTH ends), and then the receiver chip once again converts this analog signal into digital. Any distortion of this analog signal CHANGES “ones” and “zeros” in the received signal, after the second conversion at the receiver. I.E. the received “ones” and “zeros” digital signal after the S/PDIF transmission is NOT exactly the same as the signal that has been sent. And THIS IS why digital cables do make a sonic difference."

All signals are analog, but digital is unique and different type of analog signal. Risetimes are never zero and signal integrity is never perfect, so it is analog. This is not a reasonable argument alone to explain USB effects however. Things that affect digital are unique to digital. There is no error correction with USB or with S/PDIF, but errors are rare if you use reasonable cable and lengths, assuming the interfaces meet the specs. Many don't meet the specs as I discovered in 10 years of modding digital sources, both Transports and USB converters, even devices produced by Sony.

Steve N.
Empirical Audio

 

[jkeny]

USB cables have minimal effect when the USB receiver isolates common mode noise, recreates the USB signal with a very clean power supply so signal quality is optimal (no noise, rise & fall times of square waves are as good as they can be).

If this noise isolation & USB signal cleansing USB signal is don next to the audio device then it is optimal - there is no cable to distort the signal or introduce noise & what is happening upstream with cables/power, etc. has far far less influence.

My USB ISO devices do exactly this - ISO-DAC & ISO-SPDIF

 

[Simon Moon]

I have seen threads here on different ethernet cables sound different and now we read here that USB cables sound different. How is this possible when all that is being transmitted are 0's and 1's.

I am far from a skeptic because my listening experiences do suggest there is an audible difference


I ask this question because now along comes the Master Built Ultra Ultra USB cable which I will be auditioning in the coming weeks. From everything that I have been reading this MB USB cable sonically takes things to a totally different level that is leaving listeners speechlesss. I am looking forward to the audition and sharing my experiences here. My overall experience with my MB Ultra loom has taken my sound system to a totally different level so I am more than curious about their version of a USB cable even though it has an MSRP in the ozone

I understand that the MB engineers have done something which isolates the data but this apparently is nothing new

So my question is whether others have been hearing improved sonics with different makes of USB cables and if so what differences are you noting

Bold mine.

Cables, of any type, do not transmit 0's and 1's. In the case if USB cables, they transmit pulses of light. In digital audio, there are never 0's and 1's being transmitted.

These pulses, have to arrive intact, with the same timing, rise time, intensity and the same duration as they start with.

Playing devil's advocate here, I can imagine different quality cables effecting the above parameters.

 

[Legolas]

Bold mine.

Cables, of any type, do not transmit 0's and 1's. In the case if USB cables, they transmit pulses of light. In digital audio, there are never 0's and 1's being transmitted.

These pulses, have to arrive intact, with the same timing, rise time, intensity and the same duration as they start with.

Playing devil's advocate here, I can imagine different quality cables effecting the above parameters.

Pulses of current, unless it is an optical connection. So many USB cables do sound different, and IMO this can be used to an advantage, as long as you get off 'base one' Walmart cables. I have two I keep as reference at the moment. The Phasure Lush 80cm USB, and the Curious Silver 80cm. They are polar opposites. So if you want more warmth, calm down the treble a bit go for the Lush, for more detail and transparency the Curious. Oddly the Phasure cable is 200ohms which is higher than the 'standard' USB protocol. Not odd the Curious is more transparent as it has silver wires. But I must say the Lush, it is a very nice sound to my ears.

TBH I believe everything between each component affect the character or sound signature you will hear. So:
1. Mains quality, time of day, power regenerator or not etc
2. Mains cable, main plug, inlet plug, fuses
3. Ethernet, SPDIF, AES, Optical or USB from the server, power supply to it or not
4. Interconnects from DAC to the pre-amplier
5. Interconnects from pre-amplier to the power amplifier
6. Speaker cables from the power amplifier or headphone cable to the headphones (as I found out this week!)
7. Acoustics of the room

Not to forget cable isolation and vibration control.

Nightmare!!!!!

But I dig the USB cable thing, a cheap(ish) way to 'tune' your system. Remember - system synergy can be more effective than just spending kore and more dollars IMO. YMMV.

 

[allhifi]

Because ...

I have seen threads here on different ethernet cables sound different and now we read here that USB cables sound different. How is this possible when all that is being transmitted are 0's and 1's.

I am far from a skeptic because my listening experiences do suggest there is an audible difference


I ask this question because now along comes the Master Built Ultra Ultra USB cable which I will be auditioning in the coming weeks. From everything that I have been reading this MB USB cable sonically takes things to a totally different level that is leaving listeners speechlesss. I am looking forward to the audition and sharing my experiences here. My overall experience with my MB Ultra loom has taken my sound system to a totally different level so I am more than curious about their version of a USB cable even though it has an MSRP in the ozone

I understand that the MB engineers have done something which isolates the data but this apparently is nothing new

So my question is whether others have been hearing improved sonics with different makes of USB cables and if so what differences are you noting

RE: (Why Do Different USB Cables Sound Different)

Uh, Cuz they can't sound the same ? (lol)

SQ distinctions can be, and often is, dramatic. You ask "What's (/can be) noticed" ? Everything: Tonal Balance, Clarity/Resolution, Layering, Dynamics, Excitement.

Last year I decided to began my Streaming journey on the cheap; Rasp. Pi-3B, Modi-2 Uber, Rune Audio/MPD. Up and running with some basic USB cable -and after some 'run-in' time, I thought OMG -that's CRAP ! lol

I quickly decided on messing with cabling, including Ethernet cable; started with USB cable (AQ 'Carbon' (2M). OMG -Incredible. SQ went from Am radio style, to Hi-Rez. I couldn't believe the magnitude of the improvement. And so too with choice of (get this) generic Ethernet cable -tremendous variation in SQ/tonality.

Since then, upgraded DAC, and began really enjoying Streamed music -basic 98-128 Kb/s stuff. Sounds excellent.
Since my DAC has the (excellent) i2S digital interface (over HDMi), I wondered how the Gustard 'U-12' (spdif converter) to feed my DAC via i2S might sound. With a generic (10-ft. HDMi cable)- really, really bad. Ran out and purchased two cheapy AQ HDMi (2M) cable; AQ entry and model up 'Forest'. AQ entry level 'Pearl'? was better, but. Then, the Forest HDMi cable; OMG again. It was, and remains, stunning (SQ).

This set-up provides greater levels of resolution/transparency (than USB input) along with the very rare treat of greatly improved tonal realism and 3D-like instrument/vocalist reproduction. I remain both amazed, and impressed. I also remain with Streaming (as my source), current Int. Radio station at 128 kb/s.

pj

 

[Alrainbow]

As I am a lifelong skeptic I can say both do. USB is due to a few reasons
Jitter
Imp matching of both output from source and input to dac
Shielding used
Power if part of it
And a few more.
Advice if you don’t need power use a power cutter at the source

Lastly all of audio usb cables are non spec overall so none meet this detailed spec.
This is also why they sound different overall.
For the reasons above and more.

 

[dedobot]

Mainly because S/PDIF and AES3 are ancient digital audio protocols, designed with intention to be implemented easy [cheap] in consumer electronic . An file sharing protocol over the TCP/IP model, like SMB is completely different beast. Both are digital, but data transfer via SMB is fully abstracted from the carrier media, the simple S/PDIF isn't so indeed it can be viewed like digital interface with analog parts/dependencies .

 

[allhifi]

Not so fast ...

As I am a lifelong skeptic I can say both do. USB is due to a few reasons
Jitter
Imp matching of both output from source and input to dac
Shielding used
Power if part of it
And a few more.
Advice if you don’t need power use a power cutter at the source

Lastly all of audio usb cables are non spec overall so none meet this detailed spec.
This is also why they sound different overall.
For the reasons above and more.

Lifelong: Your reply reeks of "what's been said", "What's been presumed" for ions regarding SQ variances.

Rest assured, it's all 'guessing', as to the real reasons. Quantum Physics/Science shall reveal insights that should help explain in far greater detail -and accuracy.

A life-long association in hifi has provided me decades of (authentic) vital experience, expertise.

There is not one single hi-fi system, anywhere, at any price that impresses without the use of better cabling -NONE. Never, have I seen/heard one. Ever. And today, not to forget and AC power quality; Balanced/ Symmetrical (Iso. trans) Power and AC Regen. for digital and/or source components. From my experience (and countless others), AC Regen pays big dividends powering digital; DAC's Streamers, CDP's, etc. The improvements are truly spectacular.

Ever wonder how there can be dozens of cable manufacturer's/Designer's in business for decades ?

pj

 

[allhifi]

I recently had an email conversation with Serguei Timachev from Stealth Audio who provided a cogent (at least for me) explanation of why USB cables can and do sound different. Thought I'd share it below. Interesting info.

"The common (incompetent) logic AGAINST ANY premium USB cables usually is that in digital signal transmission the data errors get corrected (and the incomplete or distorted data packets get re-sent). For some reason folks do not know (or do not realize) that music is being transmitted as a STREAM, without any correction, and thus gets distorted (more or less) in a similar fashion as analog signals.

On top of that, a lot of people do not know that S/PDIF protocol for digital audio is, in fact, an ANALOG protocol: digital signal, consisting of “ones” and “zeros” gets converted into a corresponding analog signal, then this ANALOG signal gets transmitted via a “digital” transmission line (75 Ohms characteristic impedance at BOTH ends), and then the receiver chip once again converts this analog signal into digital. Any distortion of this analog signal CHANGES “ones” and “zeros” in the received signal, after the second conversion at the receiver. I.E. the received “ones” and “zeros” digital signal after the S/PDIF transmission is NOT exactly the same as the signal that has been sent. And THIS IS why digital cables do make a sonic difference."

Marty: Excellent. Thanks for sharing. Serguei Timachev is a sharp guy. Indeed, spdif is deeply flawed; separate Word Clock and/or i2s protocol (over HDMi/RJ-45) is the digital data transfer method of choice.

I had a lengthy chat with a Moderator/Owner of a well known (computer audio) forum on precisely this topic. This, authentic 'Meathead', argued Wrd. Clk/i2s is not superior to spdif ! It told me "mountains" about of this chap (not to mention names -Chris Connaker) -and his poor understanding of the very business he engages. Too funny.

In any case, Mr. Timachev suggests a reason (a very good one) but he too must realize there is much more to learn/understand. In fact, it never ends ...

pj

 

[Alrainbow]

Lifelong: Your reply reeks of "what's been said", "What's been presumed" for ions regarding SQ variances.

Rest assured, it's all 'guessing', as to the real reasons. Quantum Physics/Science shall reveal insights that should help explain in far greater detail -and accuracy.

A life-long association in hifi has provided me decades of (authentic) vital experience, expertise.

There is not one single hi-fi system, anywhere, at any price that impresses without the use of better cabling -NONE. Never, have I seen/heard one. Ever. And today, not to forget and AC power quality; Balanced/ Symmetrical (Iso. trans) Power and AC Regen. for digital and/or source components. From my experience (and countless others), AC Regen pays big dividends powering digital; DAC's Streamers, CDP's, etc. The improvements are truly spectacular.

Ever wonder how there can be dozens of cable manufacturer's/Designer's in business for decades ?
Not
pj

Bro your off the charts and seemed to be an audio god lol. Can’t help anyone who knows it all.
Maybe you sell products so I get flamed for saying they help but not iall conclusive.
You are why I don’t post much anywhere really
God’s should be worshipped at a church or temple.

Ill
Post back tonight to further shatter your world more
And nothing I post is read alone it’s me by me and others I ask as well. Enjoy your view from the temple for now.
Last part so a person buys a complete Msb sel 2 stack with dac , psu and streamer server and it’s garbage cause you say so.
I pitty your followers hahaha.

 

[Empirical Audio]

@astrostar59 : Pulses of current, unless it is an optical connection.

Not quite. These are voltage pulses, not current pulses. Risetime matters and reflections on the cable matter. Cable length can be used to mitigate the reflection problem, but not the risetime problem. Common-mode noise is definitely a problem. My old Short-Block USB filter addressed this and it worked. Devices like jkeney's take care of all of these issues. So does this:

https://sotm-usa.com/collections/sotm-ultra/products/copy-of-tx-usbultra-regenerator-1

If you are not using one of these devices with USB, you are not hearing it's real potential.

Steve N.
Empirical Audio

 

[jkeny]

I agree with Steve, common mode noise (to a lesser extent, waveform shape) is one of the last remaining issues with USB audio
Bit perfection of the USB stream can be tested without sophisticated equipment & USB audio streams, in my experience doesn't change bits i.e. it's bit perfect

 

[Alrainbow]

I still use Steve's short block on my Lampi dacs
I even use his offramp 5 too to convert to spidif best pcm is this way.
I read that usb inputs also vary in imp too wonder of that matters.
Using a shirt block makes most Cankes better and closer too. But some are made worse or better.
No rhyme or reason I can see. I now use a reclocker too for usb this also makes things better.
Steve do you still make them on special order in quantity ?

 

[Empirical Audio]

Al - I don't make the Short-Block anymore. I do however have some great inexpensive mods for your OR5 that reduce jitter. Send me an email if you are interested.

Steve N.
Empirical Audio

 

[Alrainbow]

Ty emailing you now.

 

[admin1959]

@astrostar59 : Pulses of current, unless it is an optical connection.

Not quite. These are voltage pulses, not current pulses. Risetime matters and reflections on the cable matter. Cable length can be used to mitigate the reflection problem, but not the risetime problem. Common-mode noise is definitely a problem. My old Short-Block USB filter addressed this and it worked. Devices like jkeney's take care of all of these issues. So does this:

https://sotm-usa.com/collections/sotm-ultra/products/copy-of-tx-usbultra-regenerator-1

If you are not using one of these devices with USB, you are not hearing it's real potential.

Steve N.
Empirical Audio

Steve, do you want to send me one of your USB short block if you have any kicking around? Used is fine. I want to hear what you are claiming. I used to have a long USB chain with fixers, reclockers, convertors, LPS, and ended up ditching the lot to concentrate on a simpler chain (cable only). But I am open to new knowledge Steve. PM me if you fancy the idea. If it works, cash awaits (and a glowing review), if not I'll send it back FOC.

 

[Empirical Audio]

admin - I have one left that I use myself. They are very labor intensive, so I don't build them anymore. Tired of getting minimum wage to build these...

If you gave me a refundable deposit of $250, I could let you try it I suppose. I mostly use my Ethernet interface now, not USB. I only use USB for occasional streaming. I need it back.

Have you tried one of these:

https://sotm-usa.com/collections/sotm-ultra/products/copy-of-tx-usbultra-regenerator-1

This improved my USB a lot.

Steve N.
Empirical Audio

 

[Alrainbow]

admin - I have one left that I use myself. They are very labor intensive, so I don't build them anymore. Tired of getting minimum wage to build these...

Have you tried one of these:

https://sotm-usa.com/collections/sotm-ultra/products/copy-of-tx-usbultra-regenerator-1

This improved my USB a lot.

Steve N.
Empirical Audio

Have you tried a power cutter for your usb cable also.insulate the shield at the dac too

 

[Empirical Audio]

The Short-Block cuts the power, but I use a Power Block mostly, which is a Hynes-based fast LPS providing high-quality +5V for the USB cable. This is an option for my Off-Ramp 6, but I can sell it separately for $899.00 plus shipping and PayPal fee.

https://www.audiocircle.com/index.php?topic=128620.0

Steve N.
Empirical Audio