[audioengr]

Quote:

Originally Posted by jkeny /img/forum/go_quote.gif Thanks for the clarification Steve. What SPDIF transformer configuration does the HiFace use? Would you consider galvanic isolation most worthwhile at the USB input side rather than on the output to the DAC?

I believe the secondary on the HiFace is ungrounded.

The effectiveness of the isolation depends on the power supply architecture. Isolating the USB interface, which is what I do on the Pace-Car USB, has the added benefit of making any power supply modulation caused by the USB interface unimportant. This is in addition to the benefit of breaking the ground-loop.

Steve N.
Empirical Audio

 

[audioengr]

Quote:

Originally Posted by Fujak /img/forum/go_quote.gif Hi Steve, so in the case that I'm using a Netbook 5mtrs. away from my DAC (listening position) it would make sense to use a 5m USB-cable connecting to the HiFace USB-input and on the other side to connect the SPDIF-Out directly (e.g. by adapter) to the DAC. So all the jitter, that could arise on the long way from Netbook to HiFace, coul be elminated there. The constructor of the HiFace provided in the other way round: connecting the Hiface directly to USB of the Netbook and leading the digital-out on SPDIF-cable (in my case 5mtrs.) to the SPDIF-In of the DAC. What do you (and of course all the others) about it? Fujak

Actually, the real benefit of async mode is to allow you to use a long USB cable of low quality. I use a $5 5m long cable myself. The S/PDIF cable should be between 1.5 and 2 meters for best results, and use a very good quality cable there.

Has anyone tried using a USB extension cable with the HiFace?

Steve N.
Empirical Audio

 

[audioengr]

Quote:

Originally Posted by JackRyan /img/forum/go_quote.gif good quality co-ax SPDIF cable can run at least 10-15 meters without issues.

This is true, but if you care about sound quality (low jitter), you will make this cable between 1.5 and 2m in length and very high quality.

spdif

jitter

Steve N.
Empirical Audio

 

[JackRyan]

Quote:

Originally Posted by audioengr /img/forum/go_quote.gif This is true, but if you care about sound quality (low jitter), you will make this cable between 1.5 and 2m in length and very high quality. spdif jitter Steve N. Empirical Audio

Thanks for the reading links, they are very informative. From my standpoint, whatever money to be spent on very high quality digital cables, should be invested towards a DAC that has reclocking features so as to render any jitter caused by the cable or upstream SPDIF interface irrelevant.

Not saying cables don't matter, it just seems to me that taking advantage of the capabilities of a digital medium's robustness in error correction is a better approach than chasing after a perfect square wave in the analog domain. Why are we worrying about the waveform of a digital signal when it simply should not matter if implemented properly? For example, there are no shortages of $1000 digital coax cables, but the $1000 Benchmark DAC1 doesn't really care if it's getting is 1/0's from a $1000 1.5M coax or a $50 BJC coax.

Yes I am sad that there are engineers who design these systems that bend to the will of the bean counters.

 

[audioengr]

Quote:

Originally Posted by JackRyan /img/forum/go_quote.gif Thanks for the reading links, they are very informative. From my standpoint, whatever money to be spent on very high quality digital cables, should be invested towards a DAC that has reclocking features so as to render any jitter caused by the cable or upstream SPDIF interface irrelevant. Not saying cables don't matter, it just seems to me that taking advantage of the capabilities of a digital medium's robustness in error correction is a better approach than chasing after a perfect square wave in the analog domain. Why are we worrying about the waveform of a digital signal when it simply should not matter if implemented properly? For example, there are no shortages of $1000 digital coax cables, but the $1000 Benchmark DAC1 doesn't really care if it's getting is 1/0's from a $1000 1.5M coax or a $50 BJC coax.

How did you determine this?

I have been modding DAC-1's for about 7 years. I have at least 100 of them in the field. When I change the input cable I can easily hear a difference, but my system may be more resolving than yours.

Jitter is never zero and resamplers are always affected by incoming jitter IME.

Steve N.
Empirical Audio

 

[rosgr63]

Quote:

Originally Posted by audioengr /img/forum/go_quote.gif Actually, the real benefit of async mode is to allow you to use a long USB cable of low quality. I use a $5 5m long cable myself. The S/PDIF cable should be between 1.5 and 2 meters for best results, and use a very good quality cable there. Has anyone tried using a USB extension cable with the HiFace? Steve N. Empirical Audio

Hi Steve, I am using a USB hub with a cheap USB cable and a Stereovox XV2 for Coaxial. The results are very good.

 

[hawkhead]

I tried a USB extension cable with the Hiface - a Belkin Signature cable. It was dreadful (in comparison)

 

[ironmine]

What can you guys say about this product?

eBay.com.sg: POPPULSE WIRELESS 24-96KHZ PC-LINK USB TO SPDIF FOR DAC (item 220520615850 end time Apr 02, 2010 08:37:14 SGT)

Does anyone have any experience with it?

 

[JackRyan]

Quote:

Originally Posted by audioengr /img/forum/go_quote.gif How did you determine this? I have been modding DAC-1's for about 7 years. I have at least 100 of them in the field. When I change the input cable I can easily hear a difference, but my system may be more resolving than yours. Jitter is never zero and resamplers are always affected by incoming jitter IME. Steve N. Empirical Audio

I determined it because the DAC-1 reclocks and resamples the incoming data stream before converting it into an analog signal. Now if you want to speak to the fact no electronics is perfect and therefore the reclocking/resampling circuit in the DAC1 itself will have *some* jitter, I would agree. And if you further say that the incoming line jitter may have some observable effect on the final wave form in a laboratory setting due to careless circuit design, I would also concede that point. But to assert that the effect is audible at a practical listening situation indicates one of two things: the equipment was broken, or you really do have exceptionally sensitive hearing and a very very resolving sound system.

One final note, Stereophile in this following article:

Stereophile: Bel Canto USB Link 24/96 USB-S/PDIF converter

Showed some graphs and made some comments about the DAC1's performance and susceptibility to input jitter. In the measurements section, it's mentioned:

Quote:

When I analysed the Benchmark's analog output while it decoded USB data converted to electrical S/PDIF by the Bel Canto USB Link, to all intents and purposes, the spectrum was identical to that in fig.3. It is shown in fig.4. Regardless of any jitter in the Bel Canto's output, it will not affect the Benchmark's sound quality.

Emphasis mine. But then again, the author may not have a system that was capable of resolving these easy to hear differences.

 

[audioengr]

Quote:

Originally Posted by JackRyan /img/forum/go_quote.gif I determined it because the DAC-1 reclocks and resamples the incoming data stream before converting it into an analog signal. Now if you want to speak to the fact no electronics is perfect and therefore the reclocking/resampling circuit in the DAC1 itself will have *some* jitter, I would agree. And if you further say that the incoming line jitter may have some observable effect on the final wave form in a laboratory setting due to careless circuit design, I would also concede that point. But to assert that the effect is audible at a practical listening situation indicates one of two things: the equipment was broken, or you really do have exceptionally sensitive hearing and a very very resolving sound system.

I dont have exceptional hearing, but it is good and my brain is properly trained.

I suggest you borrow a DAC-1 and try some different cables and the different interfaces yourself.

Quote:

One final note, Stereophile in this following article: Stereophile: Bel Canto USB Link 24/96 USB-S/PDIF converter Showed some graphs and made some comments about the DAC1's performance and susceptibility to input jitter. In the measurements section, it's mentioned: Emphasis mine. But then again, the author may not have a system that was capable of resolving these easy to hear differences.

Precisely. I think if you heard some of these reviewers systems you would be shocked. Very few have what I would consider a resolving system.

If you read the review of my Overdrive DAC in February TAS and the following review of Amarra in March TAS, you will see that the reviewer says that initially he could not hear any improvement using Amarra with iTunes. Then he got my Overdrive DAC and heard a significant improvement with Amarra. This is due to the fact that the jitter and the distortion and noise were reduced. More resolving.

Most audiophiles feel that their systems are resolving. Reviewers do too. Most of them are not. There is usually a layer of noise, jitter and distortion that masks a lot of improvements that can be realized from better cables, lower jitter devices and better DAC's. When someone says that cables all sound the same or they cant hear the improvement with Amarra, or differences in jitter are not audible, it is usually indicative of this masking effect.

This is why it is so critically important to spend the money wisely, improving the source first and then the DAC and then go to the rest of the system. If the source has poor quality, usually nothing you do to the rest of the system matters much.

Steve N.
Empirical Audio

 

[regal]

Quote:

Originally Posted by JackRyan /img/forum/go_quote.gif One final note, Stereophile in this following article: Stereophile: Bel Canto USB Link 24/96 USB-S/PDIF converter .

Stereophile said it so it must be true, hell I'd buy into your position more if you quoted the National Enquirer.

 

[rosgr63]

Steve I have my reservations about Amarra, as it's not compatible with all available hardware. The differences I heard in my systems were vivid from my Beresford DAC only! My other systems showed little improvement. I would not spend $1000 to buy a player to improve the sound of my Bresford for sure!

PS I personally value Steve's opinions a lot, and I highly regard his excellent products.
I often refer in my posts to his recommendations and I follow them in practice too.

 

[upstateguy]

Quote:

Originally Posted by audioengr /img/forum/go_quote.gif ....I think if you heard some of these reviewers systems you would be shocked. Very few have what I would consider a resolving system. Most audiophiles feel that their systems are resolving. Reviewers do too. Most of them are not. There is usually a layer of noise, jitter and distortion that masks a lot of improvements that can be realized from better cables, lower jitter devices and better DAC's. When someone says that cables all sound the same or they cant hear the improvement with Amarra, or differences in jitter are not audible, it is usually indicative of this masking effect. This is why it is so critically important to spend the money wisely, improving the source first and then the DAC and then go to the rest of the system. If the source has poor quality, usually nothing you do to the rest of the system matters much. Steve N. Empirical Audio

A very resolving post!

I read the recommendations for computer audio on your web site and was wondering what components would you include in a laptop system to make it resolving enough to unmask the improvements that can be realized from better cables, lower jitter devices and better DAC's?

USG

 

[audioengr]

Quote:

Originally Posted by upstateguy /img/forum/go_quote.gif A very resolving post! I read the recommendations for computer audio on your web site and was wondering what components would you include in a laptop system to make it resolving enough to unmask the improvements that can be realized from better cables, lower jitter devices and better DAC's? USG

I dont know if you are trying to be fececious (sp?) or not, but there are actually a LOT of things you can do:

1) for Mac, add Amarra or Pure Vinyl to improve iTunes
2) for PC, bypass Kmixer using Kernel Streaming or Wasapi
3) rip your tracks using dbpoweramp with Accurate Rip enabled
4) Rip to AIFF or .wav format
5) use an external device for S/PDIF conversion with its own power supply
6) change the power supply for (5) to LI or SLA battery
7) use an async protocol from USB or Firewire ports
8) choose the best-sounding USB port if you ar using USB

Steve N.
Empirical Audio

 

[haloxt]

^This is why I gave up on computer as transport, too many issues. Not saying it's bad, I actually got my computer to sound better than my other transports with a few tweaks, but it's just such a mess to overcome all the obstacles. We're starting to see products like Western Digital hard drive media players, and I'm hoping for an audio electronics company to pick up on the concept and make an audiophile version. Minimalistic hardware, accurate (or less inaccurate) software, and the convenience of storing music in a hard drive. Battery power would be nice too, I've also about had it trying to deal with "dirty power"

.