TOPPING HS02 coming

[MC_RME]

I need a ground loop breaker / hum reducer for my Fiio k5 Pro ESS (connected to a windows desktop PC and active monitors or headphones).

The K5 Pro (XMOS USB Receiver) is not USB powered and has an external power supply.

Is there any reason to better buy the HS02 or can go with HS01 without the additional power supply isolation and it is supposed to work fine? Is there anything the HS02 would do better in my case?

If you don't need as much power as the HS02 provides (true for all DACs with power supply), or its extended feature set, then you could save some money with the new Hifime USB High Speed isolator. It also uses the AD UM4166 and an additional DC/DC isolator with a bit less current (still 500 mA), but also better isolation (71 pF coupling capacity only). I know because I got one already.

Hifime Hi-Speed USB Isolator - new 2023 version

The Hifime High-Speed USB Isolator is designed specifically for audio and supports USB Hi-speed mode that is required by many Audio devices. It will prevent ground loops, prevent interference and protect your equipment against power surges.

hifimediy.com

 

[Music1969]

but also better isolation (71 pF coupling capacity only)

With your measurement gear can you see improvements with measurements with this improved isolation vs HS02?

Or it is just a theoretical improvement?

Obviously better isolation for cheaper price is an obvious 'no brainer' but also curious if HS02 isolation is already 'enough' for any situation

Like if you hookup USB DAC to gaming PC and have sub-optimal earthing, will you see difference in isolator performance at the DAC analogue output?

 

[wyup]

If you don't need as much power as the HS02 provides (true for all DACs with power supply), or its extended feature set, then you could save some money with the new Hifime USB High Speed isolator. It also uses the AD UM4166 and an additional DC/DC isolator with a bit less current (still 500 mA), but also better isolation (71 pF coupling capacity only). I know because I got one already.

Hifime Hi-Speed USB Isolator - new 2023 version

The Hifime High-Speed USB Isolator is designed specifically for audio and supports USB Hi-speed mode that is required by many Audio devices. It will prevent ground loops, prevent interference and protect your equipment against power surges.

hifimediy.com

Does the Hifime isolator reclock like HS02 and improve jitter or do they add jitter on their own?

 

[antcollinet]

Does the Hifime isolator reclock like HS02 and improve jitter or do they add jitter on their own?

Jitter is not an issue for usb audio. It is a solved issue for all audio - but it is not even an issue to be solved with USB.

 

[MC_RME]

Apart from that both units use the same chip and nothing else, so are basically identical in how they work with USB.

 

[wyup]

Jitter is not an issue for usb audio. It is a solved issue for all audio - but it is not even an issue to be solved with USB.

Jitter correction depends on the dac's implemention, you cannot take it for granted. It's better not having to correct it, and when using an isolator the data signal is retimed again, which may reduce or add jitter, depending on the crystal and chip accuracy.
"An external 24 MHz clock source is required by the AD-uM4166 to support high speed data recovery and retiming", according to its datasheet.

I have a dac connected to my tv by both toslink and usb, and toslink sounds better than usb, which sounds drier. The tv out is full of jitter, though, because optical gets microdropouts from time to time. I have a streamer with a digital transport and good clocks connected by coaxial to the dac. The sound quality is better than either. So don't tell me jitter is a solved issue because it's not, even on USB. AP jitter test may say whatever, but my ears know how it sounds.

I am considering a USB isolator for better conection to the tv usb ports, but as I don't think I have groundloop issues, my interest is that its timing feature uses good enough clocks to improve jitter, not add.

 

[antcollinet]

Jitter correction depends on the dac's implemention, you cannot take it for granted.

Not for a USB source.

For pretty much all modern dacs USB audio is a pull system rather than push (Asynchronous transfer). The DAC requests data as it is needed to keep buffers filled, so only the DAC clock is involved in the data rate from the source.

There is no need for reclocking, clock sync or any of the other processes needed for TOSLINK or other push systems. Hence jitter (of the source) is irrelevant.

 

[wyup]

Not for a USB source.

For pretty much all modern dacs USB audio is a pull system rather than push (Asynchronous transfer). The DAC requests data as it is needed to keep buffers filled, so only the DAC clock is involved in the data rate from the source.

There is no need for reclocking, clock sync or any of the other processes needed for TOSLINK or other push systems. Hence jitter (of the source) is irrelevant.

Anynchronous transfer is not a failsafe solution. It depends on the quality of the implementation. (wikipedia)
The reality is that most DDCs are usb to spdif (some of them sync-able to a master clock), and not one is spdif to usb. If usb was that perfect none of these would exist. Because good spdif transports use better clocks than regular usb async mechanism on the XMOS. And they sound better, and this is what is relevant.

 

[antcollinet]

Anynchronous transfer is not a failsafe solution. It depends on the quality of the implementation. (wikipedia)
The reality is that most DDCs are usb to spdif (some of them sync-able to a master clock), and not one is spdif to usb. If usb was that perfect none of these would exist. Because good spdif transports use better clocks than regular usb async mechanism on the XMOS. And they sound better, and this is what is relevant.

If you mean by "quality of implmentation" whether or not async is implemented or not, then worry not : pretty much all modern dacs to implement it.

And since we are talking specifically about the question if a USB isolator "reclocks" to reduce jitter - the statement that jitter is irrelevant on a usb interface still stands.

 

[wyup]

If you mean by "quality of implmentation" whether or not async is implemented or not, then worry not : pretty much all modern dacs to implement it.

And since we are talking specifically about the question if a USB isolator "reclocks" to reduce jitter - the statement that jitter is irrelevant on a usb interface still stands.

Quality of implementation means async (or any method) being implemented, of course. My dac is from last year, so it should have it.
All I say is usb sounds worse than optical, both being from the same source, the TV. And a SPDIF transport from a dedicated streamer sounds even better than both, because I check it with my own ears, live switching.

So jitter is relevant, boy it is. Usb is no perfect by any means. It's not a clean signal to begin with, go figure what noise comes from the tv. I don't know if an isolator can help regarding the incoming jitter, but the dac sure doesn't clean it well, because it sounds worse, thinner. No Audio Processor jitter test can deny it. I don't listen to 12 Khz pulse tones, but a full spectrum of music.

 

[antcollinet]

Quality of implementation means async being implemented, of course. My dac is from last year, so it should have it.
All I say is usb sounds worse than optical, both being from the same source, the TV. And a SPDIF transport from a dedicated streamer sounds even better than both, because I check it with my own ears, live switching.

So jitter is relevant, boy it is. Usb is no perfect by any means. It's not a clean signal to begin with, go figure what noise comes from the tv. I don't know if an isolator can help regarding the incoming jitter, but the dac sure doesn't clean it well, because it sounds worse, thin. No Audio Processor or jitter test can deny it. I don't listen to 12 Khz pulse tones, but a full spectrum of music.

But. you are listening sighted - likely not level matched also. So you preception of the sound can be influenced by small differences in levels, or subject to all sorts of biases**. In any case, jitter - even if it were audible - just doesn't sound like that.

**So it is far more likely that you (like everyone else) is hearing the effects of cognitive bias. Everyone is subject to this, and it is not possible to avoid it. It is simply how humans are built. What we perceive as sound even when the sound reaching our ears is unchanged, is impacted by how we feel, what we know, what we believe and what we see (etc etc) - and all those variables being tweaked by what we have experienced from the day we were born

go figure what noise comes from the tv

Can you hear the noise? As a hiss, or a hum? Because if audible that is how it presents. It doesn't change the characteristics of the sound in other ways - eg making it "thin"


See also:

What does jitter ACTUALLY sound like? (jitter test tracks)

The following website has some simulated jitter test tracks: What does jitter ACTUALLY sound like? There are seven versions of each sample. Three have periodic jitter, three have random jitter, and one is the original - untouched. In the samples we have 2µs (microseconds), 4µs, 8µs, 16µs...

www.audiosciencereview.com

 

[wyup]

But. you are listening sighted - likely not level matched also. So you preception of the sound can be influenced by small differences in levels, or subject to all sorts of biases**. In any case, jitter - even if it were audible - just doesn't sound like that.

**So it is far more likely that you (like everyone else) is hearing the effects of cognitive bias. Everyone is subject to this, and it is not possible to avoid it. It is simply how humans are built. What we perceive as sound even when the sound reaching our ears is unchanged, is impacted by how we feel, what we know, what we believe and what we see (etc etc) - and all those variables being tweaked by what we have experienced from the day we were born




Can you hear the noise? As a hiss, or a hum? Because if audible that is how it presents. It doesn't change the characteristics of the sound in other ways - eg making it "thin"


See also:

What does jitter ACTUALLY sound like? (jitter test tracks)

The following website has some simulated jitter test tracks: What does jitter ACTUALLY sound like? There are seven versions of each sample. Three have periodic jitter, three have random jitter, and one is the original - untouched. In the samples we have 2µs (microseconds), 4µs, 8µs, 16µs...

www.audiosciencereview.com

I have level matched all three inputs, and even not perfectly levelled I can distinguish enough not to be biased. I am honest and objective enough not biased to admit it wouldn't make a difference, if that'd be. No cognitive bias. I can live switch all inputs, toslink, coax and usb. All sources from the same music source. Toslink and usb share the same device, so music is synced, at the same volume. Coax playing the same file. I can distinguish sound quality not to need an A/B test.

Those jitter tests I already knew them, but those don't substitute real playing. Those files are computer generated to custom jitter patterns to various degrees. Jitter can be deterministic and non deterministic. You can't replicate real world jitter, but I can make out sound quality. I don't have any cognitive bias to justify any choice. If any source sounds better or equal, i would point it out. No need to justify myself.

By the way, differences in sound quality between USB and SPDIF wouldn't have to be exclusively jitter related (although it can manifest as that). As far as noise is concerned, (not necessarily ground loop) I wouldn't need to hear a hum or a hiss. I don't hear it now, but any noise on USB could affect the dac conversion and affect sound quality, without actually hearing any hiss or hum.

 

[pkane]

I have level matched all three inputs, and even not perfectly levelled I can distinguish enough not to be biased. I am honest and objective enough not biased to admit it wouldn't make a difference, if that'd be. No cognitive bias. I can live switch all inputs, toslink, coax and usb. All sources from the same music source. Toslink and usb share the same device, so music is synced, at the same volume. Coax playing the same file. I can distinguish sound quality not to need an A/B test.

Those jitter tests I already knew them, but those don't substitute real playing. Those files are computer generated to custom jitter patterns to various degrees. Jitter can be deterministic and non deterministic. You can't replicate real world jitter, but I can make out sound quality. I don't have any cognitive bias to justify any choice. If any source sounds better or equal, i would point it out. No need to justify myself.

By the way, differences in sound quality between USB and SPDIF wouldn't have to be exclusively jitter related (although it can manifest as that). As far as noise is concerned, (not necessarily ground loop) I wouldn't need to hear a hum or a hiss. I don't hear it now, but any noise on USB could affect the dac conversion and affect sound quality, without actually hearing any hiss or hum.

You may be honest or objective, but that has nothing to do with your brain generating impressions for you that have nothing to do with reality. This happens to everyone. You can't avoid it, you can only conduct a test that controls for these effects. This is the reason for blind random testing. All other sighted tests are simply not reliable enough, and this has nothing to do with your honesty or ability or experience, it has to do with being human.

 

[antcollinet]

No cognitive bias.

You can't avoid it - it is how we are built. It is subconscious, and a result of pre-filtering of your senses by the subconscious brain.

Here is an example (The Mckgurk effect). Even when you know how your brain is being fooled - it is still fooled.

 

[SSS]

You can't avoid it - it is how we are built. It is subconscious, and a result of pre-filtering of your senses by the subconscious brain.

Here is an example (The Mckgurk effect). Even when you know how your brain is being fooled - it is still fooled.

Was absolutely surprised. Didn't know such an effect in audio. Visual illusions are broadly known. But not that visual perception alters the perception of what you hear. Amazing.
By the way. I use and I like to use USB audio connections. With a good buffer on the receiver there in my experience is no jitter and drop-out problem recognizable. This not only for listening. Same for my measurement tools. Of course USB is not designed for ultra-hi-speed digital audio yet at this stage of time.

 

[Killingbeans]

Of course USB is not designed for ultra-hi-speed digital audio yet at this stage of time.

If the McGurk effect blew your mind, just wait till you find out how useless those ultra bit depth/sample rate audio streams are

A bit of excessiveness could possibly make the job of the DAC reconstuction filter easier (say some... I'm personally not so convinced), but the extreme stuff has "benefits" that are reserved for bats and dolphins.

 

[RichB]

You can't avoid it - it is how we are built. It is subconscious, and a result of pre-filtering of your senses by the subconscious brain.

Here is an example (The Mckgurk effect). Even when you know how your brain is being fooled - it is still fooled.

Ah, this video again.
When I buy an audio component with lips, this will be applicable.

- Rich

 

[RichB]

The purpose of the HS02 is to remove noise that could possibly negatively affect the DACs performance, including jitter effects.
ASR has well demonstrated that in this test environment, jitter is not an issue.
There are other types of interference that may not be found in the lab jitter test.

I use DietPi on RPI4's as streaming endpoints, and the HS02s subjectively provide a benefit.
I do not believe that this is in conflict with the ASR jitter rejection measurement, since this is not my environment.

I could send an HS02 and RPI4 to ASR. A test could find an improvement measured performance due to something introduced by the PI.
It may not though. If not, it would not disprove that there is a benefit in my environment. No, it would not.

I have two DAC3s and could arrange a voltage level matched A/B single blind test, but this truly a PIA.
Having done these in the past, I suspect that even a positive result, is meaningless to many.
You get flack for those here too.

The HS02 does what it says and Archimago has measurements showing that it delivers on its stated goal of reducing noise.
Ther is no hype or audiophile prose for the HS02 to be debunked.

The device works for its intended purchase, folks can try it from a vendor that takes returns.
If they like it, great, if not also great.

- Rich

 

[antcollinet]

Ah, this video again.
When I buy an audio component with lips, this will be applicable.

- Rich

If you like it, you'll be able to kiss it. A brand new way to love your gear.

 

[Superdad]

If you like it, you'll be able to kiss it. A brand new way to love your gear.

Dang! If I has thought of it 13 years ago I would have named our company KissAudio. (Surprised that name--and the web domain name--is not already taken.)