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USB to SPDIF converters shoot-out : EMU 0404 USB vs. Musiland Monitor 01 USD vs. Teralink-x vs. M2Tech hiFace - Page 63  

post #931 of 1712
Thread Starter 
Quote:
Originally Posted by regal View Post
I think the Emu is reclocking, not asynch USB.
Either way, it seems to be doing a poor job on both subjective listening and jitter measurements.

At the time I bought it, it was one of the very few usb devices capable of 24/192. Now, it seems that there are 24/96 and 24/192 converters popping out every day... So one can be more "picky" and choose a better performing converter at a lower price.
post #932 of 1712
Thread Starter 
Quote:
Originally Posted by reverendo View Post
has anybody here tested the hiFace and the other converters mentioned in this topic with the Trends Audio UD-10.1?
I'd love to have some info on it, since I'm looking for medium priced USB>AES/EBU converter.
thanks in advance
According to the post below that I found in the m2tech hiface thread, the hiface is better than the Trends. However, the Hiface doesn't come with AES/EBU.
Personally, even if my DAC had AES/EBU, I would rather use a good RCA/BNC source such as the hiface instead of using an average AES/EBU source. But that is just my personal opinion.
BTW, sonic performance aside, the Trends is limited to 16/44 and 16/48 while the hiface can do 24/192.

Quote:
Originally Posted by Mambosenior View Post
The m2 tech provides better sound, all-around, than any/all outputs from the Trends. For the price (which will probably swell like everything else) it’s a unqualified, screaming bargain. At the moment teaming it with the Maverick D1: Another outrageously good buy. I use them going into a Darkvoice 3322 driving the HD-800. The D1 also has a terrific SS earphone out which, much to my surprise, drives the HD-800 without strain or harshness.

It doesn’t take a large investment of money any more to get top quality sound. If you're sitting on the sidelines and have the necessary cash, you won't regret getting the m2tech or the D1 (or both: m2tech=$150.; D1=$199.).
post #933 of 1712
Quote:
Originally Posted by slim.a View Post
Here are some conditions/suggestions for an async converter, to be completely independant from the usb cable.
1. It has to be galvanically isolated from the computer (not draw power from the computer)
This reminded me that I have no idea what "galvanically isolated" really means. Based on the above quote, it seems to me that "galv. isolated" might mean something whcih has in independent power supply.

On the other hand, everybody said that the HifAce is galvanically isolated from the computer - but of course it draws its power from the computer! It doesn't have any other power supply.

I'm confused.
post #934 of 1712
Quote:
Originally Posted by regal View Post
When did the Emu 0404 get an asynchronous USB interface?
I've seen several sources that indicate that it works in asynchronous mode.

Ubuntu people who are writting their own drivers for the EMU:
[all variants] EMU 0404 USB new thread - Ubuntu Forums

And a readout of the USB info for the 0404 from 2007:
Re: [Alsa-user] emu 0404 USB support

The readout shows that the USB endpoints work in asynchronous mode.
post #935 of 1712
It seems as if good quality in sound isn't just a matter of asynchronous mode but also of how it is implemented. There must be a reason why the little Hiface sounds far better than the big (in comparison) EMU 0404. The same is to say to the matter of galvanic isolation.
post #936 of 1712
Quote:
Originally Posted by slim.a View Post
I have decided to not adress trolls anymore, but this post will give me the opportunity to explain something that I haven't addressed before.
Wow, that's quick, my 6th post and I am already called a troll.

Quote:
In the wonderland/digital dream world that some people seem to be living in a device such as the EMU 0404 usb is perfect.
I certainly didn't say the EMU 0404 is perfect. If you think I did and this contributed to your labeling me as a troll, I would ask you to kindly reconsider.

Quote:
It has been said that emu 0404 usb is an async device. However, putting the clock on the usb device doesn't mean that they have used an error check protocol.
I don't know what you are specifically referring to as an error check protocol, but the usage of asynchronous stream necessarily means that data from the interface is being buffered and reclocked out, rendering any jitter on the USB cable irrelevant.

Quote:
As I said earlier, I have generated the following test under the same conditions and using a low latency setting:
cable A: drop-outs
cable B: no drop-outs
In fact, I didn't think of the test by myself, it just happened that I realized (after upgrading the usb cable) that I could use lower latency settings without crackles and pops.
So if it were un-affected by the USB cable why would I hear differences and why would I generate a test where even a causual listener can here the drop outs/crackles and the absence of those.
I think your test results are very valid and highlights a tangential issue. USB, like many connection based interfaces, relies on retransmission as an error correction method. While this works well for bulk data transfers and allows ever cheaper and out-of-spec cable to be used, the same problematic cable can wreak havoc for low-latency isochronous no-retransmit data streams, as you've observed. We are truly getting to the point where a lot of the cables sold on the market are more or less defective, but seem to "work fine" for normal data purposes. If one had such a defective USB cable, then changing to a non-defective USB cable will absolutely result in an audible improvement due to lack of drop-outs. But if two cables are reliably transmitting the data stream without causing drop-outs, then any difference in jitter between the two cables should be irrelevant to the E-MU 0404 due to the asynchronous mode used.

Quote:
My listening tests concerning the EMU 0404 usb (vs. other converters) has been confirmed by Stereophile measurements.
Stereophile measured 8ns of jitter on the emu. On the same test, the M-Audio Transit has only 2ns.
The EMU 0404 usb is far from the perfect converter that would not be affected by the usb cable.
Stereophile tests certainly have value, but its dangerous to try and extrapolate information from the Stereophile measurements. The jitter measured from the EMU is from its digital output, but what can we say about the source of this jitter? Given what we know about asynchronous transfer, we can safely conclude that it is not from the USB interface as the asynchronous mode requires a separate internal clock with absolutely no reference to the USB dataframe. But without knowing in detail the specific hardware and firmware design of he 0404, we don't what parts of the circuit from the input buffer to the SPDIF output connectors caused the jitter.

As a side point, that same Stereophile article actually illustrated one of the points I made about the robustness of digital medium. With the reference DAC and Bel Canto DAC that they had on hand both containing reclocking mechanisms, the DACs were not affected by jitter. Meanwhile, the Assemblage DAC that does not correct for jitter showed much more distortion from the effects of jitter. In fact, the author commented that he could not hear a difference between the three SPDIF output devices when used with the reference DAC that corrected for jitter, though he did hear a difference with the Assemblage DAC that does not.

Quote:
Here are some conditions/suggestions for an async converter, to be completely independant from the usb cable.
1. It has to be galvanically isolated from the computer (not draw power from the computer)
2. It has to use good drivers that allow for error check and resending for lost data in the transmission
3. It has to use a large buffer inside in order to smooth the operation and not starve for data in case of momentary CPU spikes/overloads.
What's the reason for suggestion #1? Both 2 and 3 are difficult to achieve with low-latency data streams but they would indeed be excellent to implement.

Quote:
AGAIN, if you have any usefull information on how to improve the listening experience, you are welcome to post in this thread.
On the other hand, if you are just going to say that such or such is not audible, we really don't care about it.
I think it's also useful to identify the things we shouldn't worry about. After all, we don't spend our days wringing our hands over the color of the USB cable, do we?
post #937 of 1712
Quote:
Originally Posted by Fujak View Post
It seems as if good quality in sound isn't just a matter of asynchronous mode but also of how it is implemented. There must be a reason why the little Hiface sounds far better than the big (in comparison) EMU 0404. The same is to say to the matter of galvanic isolation.
I couldn't agree more! Digital medium is like a blank canvas. It offers some unique benefits over other mediums as well as some flaws, but what the end result sounds like depends heavily on actual implementation. And even with more or less well defined interfaces such as USB, Ethernet, and etc, actual implementation at higher layers of the interface can have a dramatic impact. Asynchronous mode solves a specific set of problems, but it is not a cure-all and does not make for a "perfect" device. You can have an awful sounding digital system just as you can have an aweful sounding analog system. The reverse, of course, is also true.
post #938 of 1712
Quote:
Originally Posted by regal View Post
I think the Emu is reclocking, not asynch USB.
EMU 0404 uses block mode, which is essentially Async USB. Tascam US-144 also uses async usb.

Steve N.
Empirical Audio
post #939 of 1712
Quote:
Originally Posted by dszabi View Post
On the other hand, everybody said that the HifAce is galvanically isolated from the computer - but of course it draws its power from the computer! It doesn't have any other power supply.

I'm confused.
Any SPDIF output that uses a transformer (as the HiFace does) is isolated from the downstream devices it connects to so it could be said that it is galvanically isolated. But the important area to galvanically isolate from is the USB link to the PC & this isn't the case in the HiFace (or any USB device that uses Hi-speed USB 2.0 as the Musiland & a number of other transports/DAC do)
post #940 of 1712
Quote:
Originally Posted by jkeny View Post
Any SPDIF output that uses a transformer (as the HiFace does) is isolated from the downstream devices it connects to so it could be said that it is galvanically isolated. But the important area to galvanically isolate from is the USB link to the PC & this isn't the case in the HiFace (or any USB device that uses Hi-speed USB 2.0 as the Musiland & a number of other transports/DAC do)
Not necessarily. Many of the transformer S/PDIF outputs are wired like autotransformers, with the secondary grounded. This is often done to pass FCC emissions testing with cheap cabling.

Steve N.
Empirical Audio
post #941 of 1712
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?
post #942 of 1712
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
post #943 of 1712
Fujak,

No one else responded, figure I'd chime in. The HiFace has an Asynchronous Mode USB interface, and specifically indicates that this eliminates the effects of transmission from PC to the interface, and I quote:

Quote:
28)Does hiFace works in asynchronous mode?
Sure, the transfer of data over the USB bus happens in a totally asynchronous fashion,
with respect to their retransmission to the DAC, in short packets which use all the available
bus bandwidth. Actually, hiFace is master in the transmission from PC to interface. As it
uses its low jitter oscillators to time the S/PDIF transmission, line jitter is totally
uncorrelated to data transmission from PC to interface.
Now, after reading the above, the natural reaction is to use as long a USB cable as you can. However, 5M is the limit of USB cable length and a poorly made cable can become intermitent as slim.a has demonstrated in his tests. With so much poorly made cables on the market, it can be problematic to find a in-spec cable.

On the other hand, good quality co-ax SPDIF cable can run at least 10-15 meters without issues. My favorite home audio cable place, BlueJeansCables.com will make you a custom length digital co-ax cable with high quality connectors and cable stock. I calculated about $26 for a 16-foot length of co-ax. These guys put a lot of science and effort behind their cable and gets the nod from a lot of audiophiles.

Another variable in the equation is whether the DAC you have performs any sort of reclocking, or does it simply lock on to the clock of the incoming stream. If you know that it does, then it would be beneficial to keep the USB cable as short as possible and rely on a longer high quality digital coax cable.

As you can see, so much of this depends on the specific implementation within the devices you are trying to use, that there is no hard and fast rule that says "this method is superior than that method".
post #944 of 1712
It may be cheaper to get an average quality long USB cable and a short good quality Coaxial cable.
This way you minimize your costs and maintain SQ.
Steve N is using a cheap USB cable with the hiface with good results.
post #945 of 1712
Hi JackRyan,

thanks for your contribution; it gives me a good orientation regarding my question. In connection to the posting of rosgr63 it could be a good way to test two configurations: HiFace directly to USB-out (as provided) and long Coax, and long USB cable and direct or short Coax connecting to the DAC.

In my current setup I'm using the TeraLink X2 with 5m USB and a short Coax conneting to DAC. I couldn't hear no difference to the other way round (short USB, long Coax).
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Head-Fi.org › Forums › Equipment Forums › Dedicated Source Components › USB to SPDIF converters shoot-out : EMU 0404 USB vs. Musiland Monitor 01 USD vs. Teralink-x vs. M2Tech hiFace