HiFace BNC or RCA?

Allegedly it's better so why wouldn't you?

Greediness. If I go for Hiface RCA I can use my good quality digital coax (german Klotz).
If I go BNC way I have to buy second DC1 which is costly.
I'm not sure PC/Foobar/KS/USB/HiFace/BNC can be a top source for Naim DAC -- comparable to Tranporter.
I was thinking of using this route to watch DVDs.

But if it pushes out a reference quality bitstream -- then I can afford a second pair of DC1, no problem.

Just curious

Get the BNC. If you don't think the source worthy, you can always get a BNC to RCA adapter for coffee money. I suspect you'll end up with another DC-1.

quote:

Originally posted by js:
Get the BNC. If you don't think the source worthy, you can always get a BNC to RCA adapter for coffee money. I suspect you'll end up with another DC-1.

I'm much biased towards this option!
But how long can DC1 be?

DC1 is basically out for it since it only comes in 1.2M. Which to extend a Macbook to the DAC is impractical.

BNC is "supposed" to be better but there are other arguments. It costs $30 more for the HiFace so not a big issue.

But the most important factor is the US web site where I ordered from, HiFace BNC is in stock, RCA is not.

I have M-Audio Transit and it claims low jitter and it allows me using long tosslink and long USB on the way from PC to DAC which is very practical. The negative is M-Audio drivers suck. When I plug-it out form my laptop and then come back and plug it again I often don't get connection from the first trail. Possibly the new upgrades are available but I'm so lazy and it turned out that there is no many Transit users around.

I have M-Audio Transit and it claims low jitter and it allows me using long tosslink and long USB on the way from PC to DAC which is very practical. The negative point is that M-Audio drivers suck. When I plug-it out from my laptop and then come back and plug it again I often don't get connection from the first trial. Possibly the new upgrades are available but I'm so lazy and there are not many Transit users around.

I've heard the M-Audio transit creates a terrible echo.

Not mine.

I have both the RCA and BNC versions of HiFace. I prefer the BNC with DC1. It sounds really good with all sorts of DACs, even using an RCA / BNC adapter on one end.

ference, DC1 is too short to reach my laptop. If I go this way I have to involve USB-extenders.

I will use Transporter BNC -> DC-1 -> NaimDAC BNC as the main audio system.
The laptop system is mostly for movies and voice chats and I did not bother of investing much in this.

But reading the posts here I start thinking if Foobar->KS->USB->HiFace can rival the superb digital transports like Transporter??? I tried M-Audio Transit and it didn't come close to what I get through TP (both run through the same DAC). But this is a sum of many parameters -- not only Transit performance only.
Shall I continue trials or this is a common understanding that PC-based system can not rival the top dedicated transports?

quote:

Originally posted by Colin Lorenson:
I've heard the M-Audio transit creates a terrible echo.

Where did you hear/read that? Or are you making a joke i am simply not getting.

-patrick

quote:

Originally posted by AMA:
ference, DC1 is too short to reach my laptop. If I go this way I have to involve USB-extenders.

I will use Transporter BNC -> DC-1 -> NaimDAC BNC as the main audio system.
The laptop system is mostly for movies and voice chats and I did not bother of investing much in this.

But reading the posts here I start thinking if Foobar->KS->USB->HiFace can rival the superb digital transports like Transporter??? I tried M-Audio Transit and it didn't come close to what I get through TP (both run through the same DAC). But this is a sum of many parameters -- not only Transit performance only.
Shall I continue trials or this is a common understanding that PC-based system can not rival the top dedicated transports?

HiFace is a very different animal. No comparison. Really. Actually I think it is much more to my liking than any of the interfaces I tried earlier, like Konnekt, Transit, M-Audio FW Audiophile, RME Fireface 400, Edirol UA-101, just to name a few. I really can't wait to try HiFace with a Naim DAC.

quote:

HiFace is a very different animal. No comparison. Really. Actually I think it is much more to my liking than any of the interfaces I tried earlier, like Konnekt, Transit, M-Audio FW Audiophile, RME Fireface 400, Edirol UA-101, just to name a few. I really can't wait to try HiFace with a Naim DAC.

Very encouraging introduction! I want to buy one -- just thinking which one to choose RCA or BNC.
I can buy BNC and use it with DC1 -- but I need a USB extender. Do you think this can impact the HiFace output jitter?

Let me publish my concerns. Honestly -- I was not very serious about HiFace -- not even now. I normally very suspisious about products which don't have highly regulated power supply. How could HiFace run the low jitter output if it sources a power from noisy USB (better to say VERY noisy USB). There should be a new regulation technology which we missed?
Or there is something else which I missed? But if your power is not Ok there is no way you can build a low jitter bitstream. I'm puzzled. Possibly HiFace is not that great as folks used to praise it?

quote:

Originally posted by pcstockton:

quote:

Originally posted by Colin Lorenson:
I've heard the M-Audio transit creates a terrible echo.

Where did you hear/read that? Or are you making a joke i am simply not getting.

-patrick

A joke you're not getting. It's all here on the page.....

quote:

Originally posted by AMA:

quote:

HiFace is a very different animal. No comparison. Really. Actually I think it is much more to my liking than any of the interfaces I tried earlier, like Konnekt, Transit, M-Audio FW Audiophile, RME Fireface 400, Edirol UA-101, just to name a few. I really can't wait to try HiFace with a Naim DAC.

Very encouraging introduction! I want to buy one -- just thinking which one to choose RCA or BNC.
I can buy BNC and use it with DC1 -- but I need a USB extender. Do you think this can impact the HiFace output jitter?

Let me publish my concerns. Honestly -- I was not very serious about HiFace -- not even now. I normally very suspisious about products which don't have highly regulated power supply. How could HiFace run the low jitter output if it sources a power from noisy USB (better to say VERY noisy USB). There should be a new regulation technology which we missed?
Or there is something else which I missed? But if your power is not Ok there is no way you can build a low jitter bitstream. I'm puzzled. Possibly HiFace is not that great as folks used to praise it?

Too much thinking not always beneficial Try it and you can be surprised. I have a friend who has a Metric Halo ULN2 as a Firewire - SPDIF clocked to a Meitner DAC as Clock generator. He prefers it against the HiFace on some tracks and preferes HiFace on some other tracks, so there is no clear winner, which is a praise of HiFace. I am really satisfied with it.

However if you want to make it more sophisticated you can use a battery as a power supply, it was modified by a guy on the DIY forum

,

There are other very interesting possibilities. I found and ordered a "laboratory quality" USB hub with seriously regulated power supply in a serious aluminium house and with 1A per port for experimenting (not cheap, 4 port is about 200 Euro). I feel it will be very good for all USB audio converters, in two weeks time I will know it and let you know.




The other way to use it in a better environment to use an industrial grade, low latency USB2 to Ethernet/Fiber (not cheap, more than 300 euro) or USB2 to Wireless adapter (roughly 200 Euro). Industrial grade is an important propterty as it has to be low latency and not all converters created equal. There is a very interesting wireless USB2 hub which works for 30m using wifi with an external, upgradable power supply. This way you do not have to have a computer in your music room at all, you just need to remote control it from you iPhone or something similar. There is a USB2 to power line extension as well available, but I do not like the idea. Icron is the company to watch, they have an interesting, so called ExtremeUSB® technology.

ferenc,

This had crossed my mind.

Does the powered USB provide ground isolation from the source?

Please let me know how it goes!

Thanks

Richard

Seems to me that a very short usb male to female adapter or cable could be modified by breaking the V+ between the connector and stringing a barrel jack off the female side V+ and gnd pins. Would allow any supply you want without major surgery and very little in the extra in the path. A usb hub or Y connector could very easily be modified to feed Voltage in from the second jack for the primary one while disconnecting it's V feed from the source. Simple, short, clean, and vesitile for supply experiments. I tend to not like battery supplies as much as regulated linear ones as they often sound sluggish.

Ferenc, didn't you find that the HiFace decoupled the ground? This would answer Paremus in that no further isolation would be needed. Isolating at the input side via a ps coupling would be difficult.

ferenc, very interesting gadgets! Not sure about HiFace retrofits. Actually -- despite the popular belief -- the battery pack is not enough to get regulated power supply and high quality regulation is difficult to implement in miniature scales. But external battery will definitely remove the high frequency contamination from PC pulse power supply which is one of the main sources of jitter.
The second solution seems to be more robust. But both may work well.

I suppose that Lab Brick ground is decoupled from PC?

quote:

Originally posted by AMA:

I suppose that Lab Brick ground is decoupled from PC?

I think so, but asked the manufacturer, waiting for the answer.

It is the official product descprition:

# Ultra low noise performance
# Superior voltage regulation for high current devices
# DVM probe ports to monitor device current
# Rugged cast aluminum enclosure

quote:

Originally posted by js:

Ferenc, didn't you find that the HiFace decoupled the ground?

There is a pulse transformer on the input, this is what Marco from M2tech wrote. A gentleman on the DIYadio.com, who modified the HiFace with the battery supply wrote this:

"Where you really need galvanic isolation is on the in-coming USB connection so the dirty PC ground does not have a chance to feed through to the sensitive clock(s) & clock handling chips on the unit. This galvanic isolation isn't possible with the HiFace (& Musiland USB transport/DAC) as they use hi-speed USB 2.0 operating at 480Mbps."

So here is the info I got from Mr Alan Olsen, Chief Technology Officer of Vaunix Technology Corporation regarding the isolation and the power supply of the LabBrick USB hub.

"...We cannot say that the LPH-204B is an isolated hub product, nor can we say that its ground connection is truly isolated from the host PC. This would be a misrepresentation of the facts. We can say that the +5V (VBUS) and the data lines (D+ and D-) are isolated from the host PC. We may also say that the hub is reactively decoupled from the host PC. Alternatively, we can say that the hub (including ground) is well filtered. The question ... regarding the isolated ground stems from the user's concern that ground loops and ground noise can effect the performance of his USB peripherals. This is a valid concern. Here is some more background information on isolated USB hubs. There are some isolated USB hubs available on the market. Their data transmission speed is limited to 12 Mbps (full-speed). This is because the isolation circuitry restricts transmission bandwidth and introduces significant propagation delay. This precludes operation at high speed (480 Mbps) and renders the hub useless for many applications, including video. There are no USB hubs on the market that have just the ground connection isolated. To isolate the ground connection without isolating the data lines puts the equipment at great risk to damage. A very slight ESD or transient event (power-up or power-down) can cause this damage when the ground is floating....

... The LPH-204B uses a switch mode power supply.

From a customer's perspective, this may be a bad thing as they may be concerned about switching noise. Switching noise should not be a concern. We use a proprietary design that yields a very clean output voltage. This design was originally developed for our signal generator product line. These signal generators have a specification that requires the spurious energy to be below -80 dBc! ..."

Well, this is not a proper decoupling because a ground is still linked to PC.
But once +5V is decoupled than it may work as a filter. Better to say very simple
and poor filter. He is right that full decoupling will limit the high bitrate transmission.
But the audio bitstreams fall below 12 Mbps including hi-res.

He is also right that ground is not allowed to be isolated without data line as it may result in a huge voltage difference. But I believe the optical junction may work perfect as a full decoupling at the highest possible bitrates. Just add a dedicated linear power supply and fine-clock USB port on the output and you get a perfect USB 2.0 hub.

I also agree that high quality switch mode power supply may work in this particular device. By high quality I mean PS which is not contaminated by jitter induction within the range of possible transmission clocks. This is not a big challenge -- unlike feeding the hungry amp in a wide audio range.

Technically I'm not convinced in LabBrick. But this worth a little and if someone can come out with a test review this may clarify if this gadget may work for audiophile purposes.

Gents, once again -- are you sure that HiFace is so low jitter that BNC shows up the impedance matching over RCA? I would say in normal S/PDIF outputs I had hardly heard any difference in the past. The output should be really low jitter to see BNC superiority.
I have a feeling that investment in BNC-ed HiFace along with 350$ DC-1 is not reasonable.
Possibly, RCA-ed HiFace with decent coax will do it just fine. Any objections?

quote:

Originally posted by AMA:
Gents, once again -- are you sure that HiFace is so low jitter that BNC shows up the impedance matching over RCA? I would say in normal S/PDIF outputs I had hardly heard any difference in the past. The output should be really low jitter to see BNC superiority.
I have a feeling that investment in BNC-ed HiFace along with 350$ DC-1 is not reasonable.
Possibly, RCA-ed HiFace with decent coax will do it just fine. Any objections?

As I mentioned earlier, you can buy a broadcast video coax cable like Belden Brillance series, crimped by a professional and try it with the BNC-d HiFace. Will work well I think. I have both the RCA and the BNC HiFace and I prefer the BNC version. More than 10 years ago I had a Micromega Duo CD transport and I asked one of my colleague to change its RCA connector to a BNC, using a very high quality Amphenol BNC connector. The difference was quite significant. I had few different Audio NOte DACs as well, I always liked their BNC input more. But it is me only.