DAC the better way or is there one ? USB-c vrs Optical input

[Earwax]

Just received the SMSL SU1 and my question is does the USB C input have a better signal pathway compared to optical ?

Here is my scenario, Asus Rogg Strix desktop ( quality ) using Zeskit 8K HDMI cable to the Sony Bravia XBR 55X800E then optical output to DAC RCA cables to my Harmon Kardon AVR 140 with Analog bypass mode ( digital bypass to pure Analog ) the sound seemed diminished when compared to the USB C output at rear of desktop.

For optical power supply I was using the 1 amp USB output slot of the TOMO T4 battery bank and do not recommend anyone ever purchase this unit it squeals when powered on and drawing current or when charging.

That said it probably is not the issue as it`s not high pitch noise the sound quality is degraded using the optical.

Optical cable is Blue rigger braided 6ft 24k gold plated version with aluminum shell.

I did a separate test with TV optical direct to amp no dac using another RCA cable brand Acoustic Research Pro II series but in a 12foot length and it was noticeable upgrade switching to the 6 foot so not sure if it was quality related but anyways those bases should be covered.

I`ve had quality issues with optical cables before so now I`m curious about the DAC`s using optical inputs in general.

RCA cables from DAC to AVR 140 I tried 2 different brands one UGreen $16 cad and the other more expensive FosPower $24 for a pair they sound similar when using the USB C from ASUS so can only assume there not an issue using the optical.

I don`t have optical output on my ASUS so no way to know if it`s the TV degrading the signal you never now these days....

Thank you for your time !

 

[DVDdoug]

the sound seemed diminished when compared to the USB C output at rear of desktop.

The sound should be identical unless you're getting ground-loop noise through the USB, and in that case an optical connection isolates ground preventing that problem.

Or, the USB may be "hotter" (louder) but I wouldn't expect that.

With the optical connection you are less-likely to get a sample-rate conversion. With USB, you can "play anything" and the software & drivers will automatically take care of any conversion needed to make it compatible with the DAC.

Optical (S/PDIF TSOLINK) is more limited and I think you can get higher resolution with USB, but with USB there is the possibility of it down-sampling. You can play 192kHz (or higher) audio with any-cheap USB DAC or soundcard and it will down-sample without telling you. It's like printing a high-resolution picture on a low-resolution printer. But it will still be "CD quality" or better so you won't hear any difference.

And it was noticeable upgrade switching to the 6 foot

Different cables won't make a difference unless they are defective, especially with digital connections. When the digital data gets corrupted it's usually terrible. If you weren't hearing gross glitches or dropouts it was probably your imagination. It's more common than you might think and nobody is immune. This isn't a perfect analogy but one flipped-bit in your bank account is just as likely to cause a 1-cent error a billion dollar error.

Usually, electronics are better than human hearing unless you over-drive an amplifier into distortion. Or sometimes you'll get audible noise (hum, hiss, or whine in the background). Noise is an analog problem. Different speakers (or headphones) and different room acoustics ALWAYS make a difference (better or worse).

See What is a blind ABX test? and Audiophoolery.

 

[staticV3]

does the USB C input have a better signal pathway compared to optical ?

Better in that it's asynchronous so the DAC can do its own clocking.

Worse in that it's electrically conductive so can invite ground loops and USB noise interference.

Optical cable is Blue rigger braided 6ft 24k gold plated version with aluminum shell.

Just FYI, neither gold nor aluminium nor any other metal serves any purpose for optical signal transmission.

I don`t have optical output on my ASUS so no way to know if it`s the TV degrading the signal you never now these days....

You can know though, with the help of a Hifime UR23 and free test software like REW, RMAA, Multitone Analyzer or Deltawave.

 

[Rja4000]

About the SU1, you may have a look at the Jitter test, which shows USB and Optical input.

As may be seen, there should not be any audible difference.
That may not tell the full story, but it's a very good start.

(From Amir's SU1 review)

 

[Earwax]

Thank you for your time great detail very much appreciate you guys taking the time to explain it simply

I`ll give MSL SU1 another go using the optical with another power source to cover that base even though it should not matter in theory or text book facts.

As for cables I have to disagree with so many people, I agree with the textbook facts of a digital signal using optical & HDMI but as for cables I`ve had my small share of awakenings.

Optical cables I had a cheaper quality one all plastic cheap felling plastic and harder rubber line instead of the softer rubber of others. That cable was with out a doubt audibly lower and less depth when I changed it to a higher quality brand name it was night and day difference.

That said the longer then length of optic cable the more chances you have of some kind of quality issue of the brands cable, I`ve heard others having audio quality experiences using longer optical cables I have no idea how these are designed but good to know it`s a possibility.

I have my doubts about the cables being used these days, I have had audio and video quality loss experiences with HDMI cables cheap vs average vs Higher build quality brands.

Another experience When I bought my 4K Bravia TV I swapped out the good average quality HDMI Cable to 8k cables the difference in Video clarity is obvious you will notice the upgrade from 4K cables if you have 4k TV, That said I am running video source from my PC video card.

I bought another high quality brand HDMI cable from a mainstream computer outlet store but in 4K and compared it against the 8K and I was a bit angry this is not common knowledge these days that 8K cable makes that much of a difference from a 4K cable as my TV is only 4K so makes no logical sense unless of course the 8K brand name was just that much more superior in build quality over the other similar priced brand........

Cables are not very expensive $15 cad for a superior quality cable is well worth it ? $50 cable is robbery and snake oil sales tactics ....

The Important question is at what price point does the quality stop ? from my experience in researching the cable scam it`s not the more expensive ones.

I bought the Gold plated aluminum shell optical cable for the build quality it also stated they were using a Japan design for the actual inside area that the light travels through so not being technical enough in that area I tried it.

Thanks for clearing up the gold plated input making no difference for a light transmitting optical cable that could be used as snake oil on people who don`t research what they are buying, I research everything before I give my money away, always doing as much as possible until I`m satisfied I`m not buying low quality or defective stuff I can`t return.

This would be a great discussion for a separate thread must be people here that have extensive knowledge of how these types of cables are actuality designed and how different materials can affect the light or signal traveling through them leaving a diminished signal.

 

[staticV3]

Another experience When I bought my 4K Bravia TV I swapped out the good average quality HDMI Cable to 8k cables the difference in Video clarity is obvious you will notice the upgrade from 4K cables if you have 4k TV, That said I am running video source from my PC video card.

I bought another high quality brand HDMI cable from a mainstream computer outlet store but in 4K and compared it against the 8K and I was a bit angry this is not common knowledge these days that 8K cable makes that much of a difference from a 4K cable as my TV is only 4K so makes no logical sense unless of course the 8K brand name was just that much more superior in build quality over the other similar priced brand........

Don't confuse uncontrolled impressions with fact.

Either the video settings changed between cables, the cables have image processing built in, or you fell for simple confirmation bias.

It is not physically possible for two simple cables to produce different images with identical image settings between source and TV.

The cables either transmit the bits or they don't.

 

[Earwax]

I understand your frustrations,

I cannot explain why those cables affected the sound and video what I can say is that I was purchasing HDMI cables from the Dollar store after seeing the cable scam on the news then further from others. I can`t say for certain but the optical cable might also have been from the dollar store I not sure.

It was not just on my old LG 1080 res TV but also my PC Monitor I noticed the video quality from the cheap HDMI cables

I also do not know why the 8K cable improved the video quality on my Sony Bravia I did`nt change anything and swapped them back and forth to make sure it was a very clear difference.

There has to be an explanation I`m a very observant person always assessing and reassessing to make sure I`m not just having a bad day or moment of brain fog from the 5G network I eat extremely healthy actually Vegan for 10 years now always helping people understand how there food intake is dumbing them down I also don`t want to lead anyone astray not even for a laugh it`s just not funny to me.

I enjoy factual proof when it can be found, when it can`t I learn on my own and share with others the experiences I had.

My eyes are better than 20/20 and my hearing is easily average, I know due to the hearing tone tests I take for work.

For all you Audiophiles out there It is a well proven experience that Dairy builds earwax same as sugar. I won`t say fact as I don`t want the Dairy or Medical Mafia harassing me.

 

[voodooless]

It was not just on my old LG 1080 res TV but also my PC Monitor I noticed the video quality from the cheap HDMI cables

I also do not know why the 8K cable improved the video quality on my Sony Bravia I did`nt change anything and swapped them back and forth to make sure it was a very clear difference.

This is just your bias talking. There is nothing in the cable that could improve video quality.

I`m not just having a bad day or moment of brain fog from the 5G network

What?

For all you Audiophiles out there It is a well proven experience that Dairy builds earwax same as sugar. I won`t say fact as I don`t want the Dairy or Medical Mafia harassing me.

Citation needed!

It’s seems your very far into the woo woo rabbit hole. This is Audiosciencereview. If you make claims, be prepared to back them up.

 

[Earwax]

Stating it is not possible over and over again is not helping it`s just an emotional response not a scientific one.

To say that there is no way to slow down, degrade or fragment the digital signal that could possibly have an impact on the processing there for affecting the output without factual proof is proof in it`s self.

 

[voodooless]

It’s simple computer science. If you know how it works, you know that the things you observed cannot be from a different cables. I’m not prepared to educate you on the ins and outs. There are plenty of resources that can do that. You make the claim, so the burden of proof is on your side.

 

[Earwax]

The sound should be identical unless you're getting ground-loop noise through the USB, and in that case an optical connection isolates ground preventing that problem.

Or, the USB may be "hotter" (louder) but I wouldn't expect that.

With the optical connection you are less-likely to get a sample-rate conversion. With USB, you can "play anything" and the software & drivers will automatically take care of any conversion needed to make it compatible with the DAC.

Optical (S/PDIF TSOLINK) is more limited and I think you can get higher resolution with USB, but with USB there is the possibility of it down-sampling. You can play 192kHz (or higher) audio with any-cheap USB DAC or soundcard and it will down-sample without telling you. It's like printing a high-resolution picture on a low-resolution printer. But it will still be "CD quality" or better so you won't hear any difference.


Different cables won't make a difference unless they are defective, especially with digital connections. When the digital data gets corrupted it's usually terrible. If you weren't hearing gross glitches or dropouts it was probably your imagination. It's more common than you might think and nobody is immune. This isn't a perfect analogy but one flipped-bit in your bank account is just as likely to cause a 1-cent error a billion dollar error.

Usually, electronics are better than human hearing unless you over-drive an amplifier into distortion. Or sometimes you'll get audible noise (hum, hiss, or whine in the background). Noise is an analog problem. Different speakers (or headphones) and different room acoustics ALWAYS make a difference (better or worse).

See What is a blind ABX test? and Audiophoolery.

It sounds like there is a bit more loudness while using the USB vs Optical but I can`t notice it with my Headphones ATH-M50x maybe they need to be dialed in with a parametric EQ...

Only seems noticeable using the HK AVR 140 to JBL Speakers I`m only using analog bypass in pure mode and I'm not sure if the headphone jack works in that mode...

I`m using Flac file fom PC hard drive play through foobar2000 Van Halen 316 for a reference, the guitar appears louder it`s very slight but I`m hearing it.

Tried 3 battery banks for the SMSL SU1, Tomo T4, Beats pill and Tribit Storm box Blast both have charging outputs but all Battery sources make no difference in SMSL SU1 sound quality so that base is covered.

 

[Jimbob54]

I may be missing something here but in the OP are you comparing usb from pc into the dac Vs hdmi from pc to TV then optical from TV to dac ?

I'd be amazed if optical out of TV to dac after processing was same as usb direct to dac from pc.

 

[raif71]

USB = USB Sound Better

 

[Earwax]

I may be missing something here but in the OP are you comparing usb from pc into the dac Vs hdmi from pc to TV then optical from TV to dac ?

I'd be amazed if optical out of TV to dac after processing was same as usb direct to dac from pc.

Yes you are correct comparing PC USB to DAC USB then DAC RCA to AMP RCA vs PC HDMI to TV HDMI then TV OPTICAL to DAC OPTICAL then DAC RCA to AMP RCA.

I do not have any technical way to measure the difference just my ears and much patience.

That said the USB from PC to DAC does appear to be introducing loudness vs the optical guessing probably from the AC power to my PC.

I`m using a pure DC battery source to power the DAC in Optical mode.

Other than that the music sounds identical nearly unrecognizable unless your are determined and patient seriously it`s very minor difference...

I spent a good hour or more swapping back and for from USB and OPTICAL to be sure I was hearing it. The way DVDDoug stated hotter (loudness) was a perfect explanation if you compare the 2.

For instance the guitars of Van Halen: 316 & Metallica: And justice for all, using FLAC files appear to have a slight bit more gain or sharpness again very difficult to notice.

It did appear to me a couple times using the PC USB that a very slight static noise would come through when using Youtube when just silence between the talking and other sounds. When using the optical I was not noticing it but more time would be needed for me to say for certain if your not specifically listening for it you probably wouldn't even notice it at all. Hell it could have been a ghosting noise from the internet....

No static noise difference between the 2 configurations when playing FLAC files from my hard drive.

Turned off the sound settings on my PC and TV, not sure if all optical outputs of TV`s are same design but it does not appear to be affecting the FLAC files I`m playing.

This is like splitting hairs I would not hesitate to purchase the SMSL SU1 again and again all day for use with PC USB I appreciate this quality very much !

On another note, I have great hearing since I stopped consuming all dairy products I no longer ever have earwax none I can dig all day with a Q-tip no earwax for years and years now...

 

[Roland68]

Optical cables I had a cheaper quality one all plastic cheap felling plastic and harder rubber line instead of the softer rubber of others. That cable was with out a doubt audibly lower and less depth when I changed it to a higher quality brand name it was night and day difference.

And I agree, it's technically absolutely impossible and would turn the entire physics of physics on its head.
You should really do your homework and familiarize yourself with the topic. Then you won't fall for any cable nonsense, especially not with optical cables.

The volume and the entire frequency response are encoded in zeros and ones. The optical cable only transports the digital data from A to B and definitely has no access to volume, bass, etc. That would require targeted and complex calculations and continuous changes to the optical cable in the digital data stream.
How is that supposed to work?

If someone proves this, they'll definitely win the Nobel Prize.

The only thing that can happen is the unintentional loss of data and signal contamination, e.g., through jitter, which quickly leads to dropouts.
This also applies to other digital transport paths, such as USB, SPDIF, AES, etc.

For one thing, I've worked with USB and network analyzers for more than two decades, including cables and cable routes. For another, I've conducted at least ten tests and comparisons over the past 25 years where people adamantly claimed that their optical or coaxial cables made a significant difference in digital connections. There was no difference either on the analyzers or in a standardized blind test. And even though none of these people could hear a difference in the blind test, most of them were so offended that they stopped speaking to me afterward.

 

[akafreak]

Adding my 2 cents as I have experienced this as well although with a Samsung TV. HDMI to TV and TV Optical out to DAC sounds worse than PC USB to DAC.

The reason for it is internal audio processing done by TV. Basically, TV does some internal processing for audio to sound good on weak TV speakers and feeds the same processed digital signal to Optical out. And this processing happens in the digital domain before TV's internal DAC converts it to analog and sends it to internal speakers.

I confirmed this by using USB out from TV (didn't know TVs could do this but Samsung ones do, at least mine did). Connect a USB DAC to USB ports on TV, select it as Audio Output Device in TV and compare the audio quality to when you connect the same DAC to a PC with the same USB cable. TV will sound worse.

Again to reiterate, it is not a USB vs Optical or cable quality debate. They all sound same. It is PC to DAC vs PC to TV to DAC debate. Adding a TV in between makes audio worse because of audio processing done by TV in digital domain and outputting the same processed digital signal via Optical or USB.

There may be a way to turn off this processing. I was reading an article here only to use a service remote and mess with the service menu setting. But I could not do it and therefore resorted to PC to DAC direct connection.

Adding for context : It is a default processing being done by TV. And there is no easy or user friendly way to disable it. Even if it could be done, it requires a Service remote which usually, people don't have. All audio and speech enhancement settings were turned off and the TV was still doing some default processing. And for some God only known reason, it was outputting that default processed signal over Digital connections.

 

[antcollinet]

it`s just an emotional response not a scientific one.

You have it the wrong way round. Your uncontrolled "impressions" of quality differences with working digital cables is an emotional/psychological response.

The fact that digital cables (if working) don't (audibly/visibly) change the signal is engineering fact. Stated to you by engineers with the same skills as those who design the gear in the first place.

 

[Earwax]

To say no noise can ever be introduced into a cable in every situation is non scientific reasoning.

The amount of dirty electricity these days is just nuts, add in sources of wireless data and communications along with HARRP then who actually can say for certain just how many rouge harmonic radio waves or other frequencies might have gotten into your system it`s not always text book facts that are proof lots prove nothing just look at big pharma and psychiatry...

It can be argued all day and night back and forth but if many people are hearing and or feeling a hotness then that is also scientific proof, it`s not the same world are Grandparents grew up in....

Not trying to bully anyone or force my way of thinking it just needed to be said so others can relate to my findings. It may appear somedays and not there other days.

Sure zero and ones but another source could be riding the cable...

 

[Blumlein 88]

To say no noise can ever be introduced into a cable in every situation is non scientific reasoning.

The amount of dirty electricity these days is just nuts, add in sources of wireless data and communications along with HARRP then who actually can say for certain just how many rouge harmonic radio waves or other frequencies might have gotten into your system it`s not always text book facts that are proof lots prove nothing just look at big pharma and psychiatry...

It can be argued all day and night back and forth but if many people are hearing and or feeling a hotness then that is also scientific proof, it`s not the same world are Grandparents grew up in....

Not trying to bully anyone or force my way of thinking it just needed to be said so others can relate to my findings. It may appear somedays and not there other days.

Sure zero and ones but another source could be riding the cable...

Man your calendar must be off. Today is April 7th, not April 1st.

Your uncontrolled rant reminds one why if many people are hearing or feeling a hotness it is NOT scientific proof.

One of the key advances of digital is immunity from outside noise corrupting the signal. There are some situations where something else might slightly effect the analog output even if the digits get thru. However, solutions to that are generally somewhere between pretty good and fully effective. The other unhinged comments don't need any commentary. Get a grip friend!

 

[AdamG]

To say no noise can ever be introduced into a cable in every situation is non scientific reasoning.

The amount of dirty electricity these days is just nuts, add in sources of wireless data and communications along with HARRP then who actually can say for certain just how many rouge harmonic radio waves or other frequencies might have gotten into your system it`s not always text book facts that are proof lots prove nothing just look at big pharma and psychiatry...

It can be argued all day and night back and forth but if many people are hearing and or feeling a hotness then that is also scientific proof, it`s not the same world are Grandparents grew up in....

Not trying to bully anyone or force my way of thinking it just needed to be said so others can relate to my findings. It may appear somedays and not there other days.

Sure zero and ones but another source could be riding the cable...

Take some time to study the amount of cables and cable noise testing that has been conducted by our Host Amir. Read his reviews and findings. Modern electronics have robust built in noise filtering systems that mitigate any electrical noise to levels below human perception and the data generated from multiple tests prove this out. People saying they hear or feel “hotness” is not Scientific proof. This is called anecdotal subjective perception and opinion. This is not repeatable by third parties and therefore wholly unverifiable. Not denying that people might think of feel that they are hearing or sensing something. But this is normally proven out to be something other than actual fact. As a scientific/engineering community we deal with facts that can be measured and reproduced by others with resulting comparable data that either confirms the claim or invalidates the claim.

If you are going to make such claims that defy known engineering performance and data. You are going to need to bring some type of proof/data that substantiates your claims. It’s not personal. The ability to reproduce supporting data is at the foundation of Scientific testing and data comparison. Please go watch some of Amir’s Testing Videos on the extensive various cable testing he has conducted. You can find a link to the Video Library in my Signature below.