[mmerrill99]

Quote:

Originally Posted by oqvist /img/forum/go_quote.gif What is the theory about this being better then say the spdif out of an elite Pro? How can USB to spdif be > spdif out of a better soundcard? Its not really that cheap 150$ which is essentially an Essence ST to put things into context. The mod adds some on top of that I am sure too.

Theory is great to discuss but it only defines the limits of a particular approach not the reality of that approach - what I'm trying to say (awkwardly) is that it's down to implementation at the end of the day. You can see this in my mods - I didn't change the theory of how it was operating just the implementation.

The strengths of the Hiface are:
- it is outside the computer so it doesn't reside in an electrically noisy & hostile RF environment. In theory it's important to avoid as much disturbance both electrical & physical as possible.
- it operates asynchronously so it doesn't rely on the computers clock for it's timing. This is theoretically the best USB communication
- it has implemented the clocks in a very direct manner i.e. with as little processing as possible. I improve the power to the clock handling circuits which allows them to better reach their theoretical potential.
- I believe another theoretical advantage of these recent asynch 24/192 transports (the Hiface & the Musiland) is it's use of USB 2.0. I believe that the speed of USB 2.0 (480mBps) is also helping to make these transports to avoid glitches & jumps in sound i.e. they are more impervious to the processing going on at the computer. This may well help it to sound better?
- Another advantage may be the use of the Cypress USB receiver chip. This is used in both the Musiland & Hiface. I haven't looked into this chip too deeply to know what if any advantage it might have.

Is this enough to be getting on with?

 

[punk_guy182]

Quote:

Originally Posted by jkeny /img/forum/go_quote.gif Is this enough to be getting on with?

Yes! Thank you very much jkeny for taking the time to explain all the great aspects of the hiFace and your mod!

 

[oqvist]

Quote:

Originally Posted by jkeny /img/forum/go_quote.gif Theory is great to discuss but it only defines the limits of a particular approach not the reality of that approach - what I'm trying to say (awkwardly) is that it's down to implementation at the end of the day. You can see this in my mods - I didn't change the theory of how it was operating just the implementation. The strengths of the Hiface are: - it is outside the computer so it doesn't reside in an electrically noisy & hostile RF environment. In theory it's important to avoid as much disturbance both electrical & physical as possible. - it operates asynchronously so it doesn't rely on the computers clock for it's timing. This is theoretically the best USB communication - it has implemented the clocks in a very direct manner i.e. with as little processing as possible. I improve the power to the clock handling circuits which allows them to better reach their theoretical potential. - I believe another theoretical advantage of these recent asynch 24/192 transports (the Hiface & the Musiland) is it's use of USB 2.0. I believe that the speed of USB 2.0 (480mBps) is also helping to make these transports to avoid glitches & jumps in sound i.e. they are more impervious to the processing going on at the computer. This may well help it to sound better? - Another advantage may be the use of the Cypress USB receiver chip. This is used in both the Musiland & Hiface. I haven't looked into this chip too deeply to know what if any advantage it might have. Is this enough to be getting on with?

Thanks This and the email you sent helps resolve some of the mystery. I am not expecting you to proove anything I just have no idea how this stuff works.

Take my Elite Pro or Essence ST. I have them sitting well away from anything and they are both shielded. If I would attach the hi face through USB it would be much closer my video card and other nasty things. If I get the boxed one I could move it further away and solve that. Al though I have up to 6 usb devices connected at one time it will share power so maybe the signal will be less then optimum anyway? I currently dedicate a separate line from my PSU to my soundcard. My Silverstone Zeus has 4 lines. I generally put some more on to it to get it operating at maximum efficiency on such devices like fans that are constant speeds.

So if I have little to no EMI/RFI and my PSU which is one of the most expensive PSUs build for stable voltages are up to the task. The benefits would mainly be perhaps even cleaner power on the hiface still?

Also this? "it operates asynchronously so it doesn't rely on the computers clock for it's timing. This is theoretically the best USB communication"... Soundcards like Elite PRo and Essence ST are they synchronous to the computer clock? The Essence ST has a jitter clock and my audio GD DAC also have some advanced anti jitter mumbo jumbo. DSP that is supposed to make the transport a bit less crucial.

Would love comments from people having one of those soundcards or the STX using coaxial or optical out that moved to the Hiface and what level of difference there are. Or if I should wait if I decide to get a dead silent net book.

 

[slim.a]

Quote:

Originally Posted by oqvist /img/forum/go_quote.gif Thanks This and the email you sent helps resolve some of the mystery. I am not expecting you to proove anything I just have no idea how this stuff works. Take my Elite Pro or Essence ST. I have them sitting well away from anything and they are both shielded. If I would attach the hi face through USB it would be much closer my video card and other nasty things. If I get the boxed one I could move it further away and solve that. Al though I have up to 6 usb devices connected at one time it will share power so maybe the signal will be less then optimum anyway? I currently dedicate a separate line from my PSU to my soundcard. My Silverstone Zeus has 4 lines. I generally put some more on to it to get it operating at maximum efficiency on such devices like fans that are constant speeds. So if I have little to no EMI/RFI and my PSU which is one of the most expensive PSUs build for stable voltages are up to the task. The benefits would mainly be perhaps even cleaner power on the hiface still? Also this? "it operates asynchronously so it doesn't rely on the computers clock for it's timing. This is theoretically the best USB communication"... Soundcards like Elite PRo and Essence ST are they synchronous to the computer clock? The Essence ST has a jitter clock and my audio GD DAC also have some advanced anti jitter mumbo jumbo. DSP that is supposed to make the transport a bit less crucial. Would love comments from people having one of those soundcards or the STX using coaxial or optical out that moved to the Hiface and what level of difference there are. Or if I should wait if I decide to get a dead silent net book.

There a lot of factors that can affect the performance of the transport: clock jitter, phase noise clock, power supply, ground traces, output transformer, output impedance, quality of the connectors, ...

The Elite Pro and the Essential were not build from the ground up to serve as a transport. For example they don't use true audio clocks. It means that when you are listening to 44.1 CD (or any multiple such 88.2 or 176.4), their clock has to be derived from a 48 multiple which makes things even worse.
The Esi Julia use true audio clocks (one for 44.1 multiples and one for the 48 multiples). I remember reading a user (on the m2tech thread) saying that the hiface was a pretty big improvement over the Pro PCI Esi Julia.
I would also like to see the clock phase noise of the clocks being used in those soundcards. (The hiface clocks for example are -78db at 10hz and -140db at 1khz which is relatively low). Those figures are far more important than ppm for example.

Jkeny's mods have addressed the one weakness that the hiface had: the power supply. The hiface draws its power supply from the computer: even if you put the best commercial computer power supply, it will still have much higher noise levels than the battery power supply he is using for his mod. By bypassing the 3.3 voltage regulators and "injecting" directly the very low noise battery power supply, the benefits of that battery power supply are even more appreciated. Even the best voltage regulators (regardless of the power supply) will have some kind of noise.

As for the Audio-gd DAC you are mentioning, I did my tests with a similar one (the dac19dsp) and it is defintely sensitive to the quality of the transport. Kingwa, the designer of the dac, also says that while in theory it shouldn't be affected by the quality of the transport, it is the case in practice.

I haven't listened to neither the Elite Pro nor the Essence in my system, so I can only speculate. However, my best guess given everything I know about jitter and digital design is that the Elite Pro or the Essence ST are no match for his modded hiface. The stock hiface already had better measurement than the professional PCI LynxTwo card (which is a few steps above consumer cards such as the Elite Pro and the Essence ST), so it would be highly unlikely if the modded hiface didn't outperform by a very large margin consumer PCI cards such as the Elite Pro and the Essence ST.

ps: the measurements about the hiface I am referring to are here: http://www.head-fi.org/forums/f46/us...ml#post6063226
pps: I am making my assumptions about jitter and transports, simply because a good measuring and sounding transport doesn't happen by accident as there are a lot of conditions to fulfil to do so.

 

[oqvist]

Thanks. Even wiser now.
We have the same DAC19 DSP I believe.

I always thought the Elite Pro had native support for bit perfect. Running 44.1 hertz helps a LOT on it. So you say it goes from 48 to 44.1 hertz still? Much better then trying to get the same result through foobar with ASIO or WASAPI anyway. Is it a plus having a jitter clock on both on transport and on DAC?

 

[slim.a]

Quote:

Originally Posted by oqvist /img/forum/go_quote.gif Thanks. Even wiser now. We have the same DAC19 DSP I believe. I always thought the Elite Pro had native support for bit perfect. Running 44.1 hertz helps a LOT on it. So you say it goes from 48 to 44.1 hertz still? Much better then trying to get the same result through foobar with ASIO or WASAPI anyway. Is it a plus having a jitter clock on both on transport and on DAC?

Sorry, my explanation wasn't very clear I think. The Elite Pro might be perfect but the problem lies in the way the clocks are being handled.
For instance, the X-Fi seems to have only one clock at 24.576mhz which is perfect for playing back 48khz as it a 512x multiple.
Let's assume that you want to play a 44.1khz, if the data is bitperfect, the 24.576mhz has to be derived someway to give the 44.1 frequency. If you do the math, the 24.576 has to be divided by a non integer (557.278911...) which is not easy to do and will undoubtedly increase the jitter. So even if the x-fi used an ultra low jitter clock (which it doesn't seem to be the case), it would still have to go through a lot of steps.
The Hiface (and other high end units) use 2 clocks to avoid that problem.

So it is not a problem about the data (bit perfectness) but rather about the timing of the data (clock jitter, clock phase noise, ...)

Concerning your question about the "jitter clock", there are many ways to connect a transport to a DAC. You can read this article here: The Digital Forest : LessLoss high end audio power cables, video power cables, audiophile power cables, audiophile cables
The way we connect our DACs to the transports (by slaving them) is the least effective way but it is also the easiest to implement.

By the way, you seem to misusing the term "jitter clock". Maybe you mean "low jitter clock"? But in any case, I doubt that you will find a low jitter clock in a consumer device such as the Elite Pro.

 

[oqvist]

Elite Pro doesn´t have a low jitter clock. The Essence ST has it though apart from the STX.

 

[gattari]

Jkeny I hope you read my e-mail.
I wonder where I can buy in europe a battery charger for modded hiface.
You had suggested me this http://www.all-battery.com/TenergyLi...rger01300.aspx but not in Europe.
I also wanted to know roughly how long approximately it takes for modding.
I already sent my hiface to your own address yesterday.
Ciao

 

[mmerrill99]

Quote:

Originally Posted by gattari /img/forum/go_quote.gif Jkeny I hope you read my e-mail. I wonder where I can buy in europe a battery charger for modded hiface. You had suggested me this http://www.all-battery.com/TenergyLi...rger01300.aspx but not in Europe. I also wanted to know roughly how long approximately it takes for modding. I already sent my hiface to your own address yesterday. Ciao

Yes, our North American friends are well catered for

. Unfortunately I can't get these units shipped to Ireland fro a reasonable cost & I haven't found a European source yet. I'm working on other solutions & expect to have some news shortly.

It won't take long for modding (days) but transportation of parts & units is causing some issues at the moment due, I believe, to a small problem of an erupting volcano

 

[mmerrill99]

Other sources for the correct battery charger:

$20 : Smart Charger (0.7 A) for 3.2V (1 cells) LiFePO4 Battery Pack, 100-240VAC, CE listed
$23: Smart Charger (3.0A) for 3.2V Li-FePO4 Battery Pack (1 cell, Standard Female Tamiya plug, 3.8V cut-off)
$25: Smart Charger (6.0A) for 3.2V (1cells) LiFePO4 Battery Pack, 100-240VAC, CE listed

These will ship via USPS if you ask them & the last one on the list has a 2.1mm DC plug (which fiits the 2.1mm DC socket on the Hiface box) & seems to have an IEC inlet so different cables can be used (3 pin

)

 

[hawkhead]

John
$85 for shipping! - think I'm going to start a new business

Will search for something closer . . . .

 

[mmerrill99]

Quote:

Originally Posted by hawkhead /img/forum/go_quote.gif John $85 for shipping! - think I'm going to start a new business Will search for something closer . . . .

Yes ridiculous, but they will ship via USPS if you ask them. However they tell me that USPS has no tracking or registered insurance protection which I don't believe & haven't had the time to check.

 

[hawkhead]

Not perfect but much more reasonable:

3.2V 2A Smart Charger for Single Cell LiFePO4 Battery on eBay (end time 04-May-10 00:27:04 BST)

 

[mmerrill99]

Quote:

Originally Posted by hawkhead /img/forum/go_quote.gif Not perfect but much more reasonable: 3.2V 2A Smart Charger for Single Cell LiFePO4 Battery on eBay (end time 04-May-10 00:27:04 BST)

Yep, but be aware that you will need a 2.1mm DC plug for the socket on the boxed Hiface

 

[qusp]

a very good low noise power supply can indeed approach and sometimes better batteries IMO. batteries are easier to do it with for sure. how do you address charging John? BTW I am in the middle of sending you a PM about this over at DIYA