[Dynobot]

Then I take it you are going to trade your wife for her HP and give her your Mac right?

 

[csholtmeier]

Quote:

Then I take it you are going to trade your wife for her HP and give her your Mac right?

Haha! She's actually using it right now. I don't think give is the right word, as the Mac accompanies me on many business trips.

 

[upstateguy]

 
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Dynobot, Good suggestions. A FAQ for each Audio-gd product would help too from what I've seen from other manufacturer websites. The DI has two clocks? Sounds like what the Hiface had too and people were complaining about their clock sizes. Do they both use the same MHZ? I forgot what each Hiface clock did but I sort of remember they each served a different function.

The HiFace actually had 3 clocks.
 

 
from the left: 
 

 
the the two main clocks
 

 
 
the little 22.579 clock was the issue with the so called "bad" HiFaces and has since been replace with a full size MIC 22.579.  AFAIK all HiFaces now have two large clocks like this
 

 

 

[haloxt]

Quote:

I've discovered, quite accidentally, that my wife's HP Mini 1000 sounds much better than my MacBook Pro with the DI. I had upgraded the OS to W7 and decided to give it a shot with my rig. The difference is far from subtle. Chain is DI>DAC19>C2. It's as if there has been a layer of filth removed from a window. I've been furiosly plugging in different cans and listening to music, the difference is just amazing. Amazing vividness and deeper bass. My LP Sextetts now have a solid and satisfying low end. The monitor amp I've been using for my HE-6's is on the fritz, I can't wait until my Virtue One.2 gets here.

I hear windows 7 sound is bit-perfect, meaning no kmixer software doing poor quality resampling from 44.1khz to 48khz. Older versions of windows would do inaccurate resampling which messed with the sound, so some audiophiles would use bit-perfect software like asio, wasapi and ks. I used to try to be bit-perfect police trying to make sure people using computer as transport had bit-perfect, but figure it's a moot point now that the newest windows os doesn't use kmixer . Almost reason enough for me to upgrade, but a little ticked at microsoft for inventing vista.

 

[lag0a]

I think everyone's level of bitperfect is different. I'm waiting for an OS dedicated to audio only with total control over the cpu for processing the audio data only, and use only its  l1 and l2 cache or fastest processing part of the cpu with the fastest data transfer rate to a motherboard built and dedicated to audio only with one point (CPU) to point (Motherboard) to point ( RCA or BNC or whatever digital output). I wonder if some kind of built in ram into the motherboard is faster than ddr3 ram that you slot in. Then you can use some kind of external hdd as the music server that wouldn't interfere with the whole point to point to point process. Also each CPU, Motherboard, RAM, External hdd uses its own linear power supply.

 

[csholtmeier]

Quote:

Quote:

I've discovered, quite accidentally, that my wife's HP Mini 1000 sounds much better than my MacBook Pro with the DI. I had upgraded the OS to W7 and decided to give it a shot with my rig. The difference is far from subtle. Chain is DI>DAC19>C2. It's as if there has been a layer of filth removed from a window. I've been furiosly plugging in different cans and listening to music, the difference is just amazing. Amazing vividness and deeper bass. My LP Sextetts now have a solid and satisfying low end. The monitor amp I've been using for my HE-6's is on the fritz, I can't wait until my Virtue One.2 gets here.

I hear windows 7 sound is bit-perfect, meaning no kmixer software doing poor quality resampling from 44.1khz to 48khz. Older versions of windows would do inaccurate resampling which messed with the sound, so some audiophiles would use bit-perfect software like asio, wasapi and ks. I used to try to be bit-perfect police trying to make sure people using computer as transport had bit-perfect, but figure it's a moot point now that the newest windows os doesn't use kmixer . Almost reason enough for me to upgrade, but a little ticked at microsoft for inventing vista.

So, following this line of thinking, if I load Windows 7 on my Mac via Bootcamp I will get the same SQ as the HP?

 

[ninjikiran]

Quote:

I think everyone's level of bitperfect is different. I'm waiting for an OS dedicated to audio only with total control over the cpu for processing the audio data only, and use only its  l1 and l2 cache or fastest processing part of the cpu with the fastest data transfer rate to a motherboard built and dedicated to audio only with one point (CPU) to point (Motherboard) to point ( RCA or BNC or whatever digital output). I wonder if some kind of built in ram into the motherboard is faster than ddr3 ram that you slot in. Then you can use some kind of external hdd as the music server that wouldn't interfere with the whole point to point to point process. Also each CPU, Motherboard, RAM, External hdd uses its own linear power supply.

If you want an OS dedicated to "audio" load up Linux, and set real time scheduelling to audio processes with the real time kernel.

 

[haloxt]

Quote:

So, following this line of thinking, if I load Windows 7 on my Mac via Bootcamp I will get the same SQ as the HP?

No, mac is usually bit-perfect. It's just older windows would take all the audio from different sources (like winamp and a game) and mix it all together with kmixer, and mess with the data.

 

[littletree76]

 
Quote:

I didn't know if iMac had SPDIF or not. My own experiment suggest the Stagedac is quite immune to jitter so I am still wondering if investing in something like the DI is wise. Although those USB to SPDIF might improve other part of the signal?? I also tried different optical cables (polymer and high strand glass) and couldn't detect differences in my system.
Anyway what are the improvement from using the DI over an optical cable straight from your iMac?

StageDAC does have over-sampling (2x, 4x, 8x) built in with its WM8804 SPDIF receiver, so that might be the reason why jitter can be improved. To really appreciate effect of jitter and since StageDAC comes with both optical and coaxial digital inputs, you should compare sound outputs between best coaxial cable and worst polymer optical cable to convince yourself. The oversampling switch should be set to minimum (2x) at top position.
 
Either HiFace EVO or Digital Interface reduce jitter by improving pulse waveform (less ringing and better slew rate) through better power line regulation, better reference clocks and proprietary driver for asynchronous mode rather than normal adaptive mode (HiFace EVO) or digital signal processing (Digital Interface). On my iMac, when polymer optical cable is swapped with either USB-to-SPDIF converter, immediately I can hear better clarity and improved bass response (more and tighter impact) and the effect is not subtle (I don't have to try very hard in listening). It does not matter whether I use good/short NuForce Impulse USB cable or long normal data USB cable between the iMac and the converters.
 
iMac [rear USB2.0 port] --> NuForce Impulse USB cable -> [USB] USB-to-SPDIF converter [coaxial] --> Belden 1800F 110ohm digital audio cable --> [coaxial] StageDAC [fixed level line output] --> KingRex T20 amplifier -> KEF iQ10 bookshelf speakers
 
Just like any long term Mac user, I see USB interface as something from PC world and FireWire 400/800 (IEEE 1394 a/b) suppose to be technically superior over USB 1.1/2.0. Too bad popularity win over technical superiority between Firewire and USB otherwise we should have FireWire-to-SPDIF instead of USB-to-SPDIF converter. Nevertheless USB interface has been improving from version 1.1 to version 2.0 and to version 3.0 now and has served good purpose in this case in improving audio quality.
 
 

 

[Dynobot]

Windows 7 Exclusive mode = Bit perfect
 
Use ASIO or Wasapi and you are bit perfect.
 
Sound quality would be the similar but not exactly the same because you still have different hardware.
 
Furthermore it always pay to try different things, software etc....you might want to try Re-Clock with the appropriate music software.  Most people who try it love it.

 

[uelover]

Hmm why would you recommend him to compare a good coaxial cable with a lousy optical cable? The inherent jitter in optical cable is high and good optical cable actually reduces that (though not as much as what I would desire it to be). Coaxial cables are known to display a wider variance in sonic signature across different cables compared to toslink cable. If I compare a cheap toslink against a cheap coaxial, even if they are of the same brand, I may just conclude that toslink is better. Of course, when it comes to good quality coax cable, even the 1 grand toslink and USB cable cannot match it.
 
I know zenpunk mentioned that he couldn't hear a difference between cheap plastic and glass but I am hearing a difference between cheap plastic and good plastic optical cable already and the difference is clearly audible. The difference is not the kind of difference between Beyer and Senn cans but they are the kind when you must sit down and listen through how vocals are portrayed, how the instruments sound and the soundstage and etc. Takes time to feel how the music are portrayed differently.
 
I have StageDAC myself and a good optical cable clearly gives the edge over the bundled USB cable. A better USB cable would probably pull the trick off too. The ability of the USB cable to carry the digital signal is important. However, the onboard USB to SPDIF converter on your DAC is very important too.
 
All DAC has their own USB to SPDIF converter (Burr-Brown PCM2704 in the case of StageDAC) and this is the extra thing that differentiate the sound of the USB input from SPDIF input. 
 
A good DAC designed for use with computer by right should have an USB to SPDIF converter that is as good as DI/Hiface. However, whenever that is not the case, DI/HiFace/EA/etc comes into the picture. They just allow us to bypass the USB to SPDIF converter inside our DAC.
 
The StageDAC USB input is pretty decent. Nonetheless, Jan recommended me to use Optical out from my Macbook pro unless I wanted to play 192khz high res file which I have none. Some people in the previous posts have mentioned that DI makes their music sounds better. I am not downplaying anyone's findings and hearing but still it is something which is best for you to find out yourself. Just keep in mind that different coaxial cable gives a different feel to the music too, just like how I find monoprice toslink to sound muffled after I have heard my VDH toslink. Monoprice toslink is still good though when I first heard it.
 
If we really want to be a perfectionist, we can get the best power cord, best PSU for our computer, best SSD drive, best SATA cable, best motherboard and etc to reduce noise and jitter in every aspects too. But at the end of the day, all those money would still be better spend on just getting a good DAC (even if we are just using a lousy USB cable).
 
But well, Audio-GD, HiFace and many other brands have given us poor head-fiers a lifeline to obtain decent sound out from our standard computers through their cheap (or not so cheap) USB to SPDIF converters.
 
I am just not so comfortable with adding so many hardwares/cables along the audio path to my DAC as there will be signal drop here and there. But well, that is just on theory.

 
Quote:

StageDAC does have over-sampling (2x, 4x, 8x) built in with its WM8804 SPDIF receiver, so that might be the reason why jitter can be improved. To really appreciate effect of jitter and since StageDAC comes with both optical and coaxial digital inputs, you should compare sound outputs between best coaxial cable and worst polymer optical cable to convince yourself. The oversampling switch should be set to minimum (2x) at top position.
 
Either HiFace EVO or Digital Interface reduce jitter by improving pulse waveform (less ringing and better slew rate) through better power line regulation, better reference clocks and proprietary driver for asynchronous mode rather than normal adaptive mode (HiFace EVO) or digital signal processing (Digital Interface). On my iMac, when polymer optical cable is swapped with either USB-to-SPDIF converter, immediately I can hear better clarity and improved bass response (more and tighter impact) and the effect is not subtle (I don't have to try very hard in listening). It does not matter whether I use good/short NuForce Impulse USB cable or long normal data USB cable between the iMac and the converters.
 
iMac [rear USB2.0 port] --> NuForce Impulse USB cable -> [USB] USB-to-SPDIF converter [coaxial] --> Belden 1800F 110ohm digital audio cable --> [coaxial] StageDAC [fixed level line output] --> KingRex T20 amplifier -> KEF iQ10 bookshelf speakers
 
Just like any long term Mac user, I see USB interface as something from PC world and FireWire 400/800 (IEEE 1394 a/b) suppose to be technically superior over USB 1.1/2.0. Too bad popularity win over technical superiority between Firewire and USB otherwise we should have FireWire-to-SPDIF instead of USB-to-SPDIF converter. Nevertheless USB interface has been improving from version 1.1 to version 2.0 and to version 3.0 now and has served good purpose in this case in improving audio quality.
 
 

 

[littletree76]

Quote:
Hmm why would you recommend him to compare a good coaxial cable with a lousy optical cable? The inherent jitter in optical cable is high and good optical cable actually reduces that (though not as much as what I would desire it to be). Coaxial cables are known to display a wider variance in sonic signature across different cables compared to toslink cable. If I compare a cheap toslink against a cheap coaxial, even if they are of the same brand, I may just conclude that toslink is better. Of course, when it comes to good quality coax cable, even the 1 grand toslink and USB cable cannot match it.
------------
 
I am not interested in sound signature of cable rather jitter caused by different types/grades of cables. Thus to have maximum jitter difference, comparison is made between worst optical cable against best coaxial cable to allow him to hear a difference due to jitter. The comparison has nothing to do with your personal preference.
 
Quote:
I am just not so comfortable with adding so many hardwares/cables along the audio path to my DAC as there will be signal drop here and there. But well, that is just on theory.
-----------
 
Sorry we are talking about digital signal but not analog signal, so what matter most is timing of digital pulse (jitter) but not negligible voltage drop along the line. All USB-to-SPDIF converters are dealing with digital signal rather than analog signal. Hope you put thing in proper perspective before making any comparison.

 

[Dynobot]

Be careful, a comparison might not support accepted Dogma.
 
The Ears are lousy at reading specs and measurements.
 
This leaves the question, if your ears like toslink, what will you do?  Many people like toslink better but still go with coax just out of principle.

 

[uelover]

.

 

[uelover]

Quote:

I am saying that listening via a better coax cable will not only incorporate the benefit of less jitter but also other effects such as the sonic signature of the cable itself. There is no way we can isolate them when we listen to them.
 
Comparing cables of the same class, one with more jitter and the other with less, will help to isolate the comparison and allow us to hear the impact of jitter better. For example, one may prefer QED coax better because it is brighter and more transparent or that VHD coax sounds more natural and warmer and thus claimed that coax > usb but that is nothing to do with jitter at all.
 
Yeah, if you are assuming 100% efficiency rate in all the components used in an ideal world.
 
Quote:

Quote:
Hmm why would you recommend him to compare a good coaxial cable with a lousy optical cable? The inherent jitter in optical cable is high and good optical cable actually reduces that (though not as much as what I would desire it to be). Coaxial cables are known to display a wider variance in sonic signature across different cables compared to toslink cable. If I compare a cheap toslink against a cheap coaxial, even if they are of the same brand, I may just conclude that toslink is better. Of course, when it comes to good quality coax cable, even the 1 grand toslink and USB cable cannot match it.
------------
 
I am not interested in sound signature of cable rather jitter caused by different types/grades of cables. Thus to have maximum jitter difference, comparison is made between worst optical cable against best coaxial cable to allow him to hear a difference due to jitter. The comparison has nothing to do with your personal preference.
 
Quote:
I am just not so comfortable with adding so many hardwares/cables along the audio path to my DAC as there will be signal drop here and there. But well, that is just on theory.
-----------
 
Sorry we are talking about digital signal but not analog signal, so what matter most is timing of digital pulse (jitter) but not negligible voltage drop along the line. All USB-to-SPDIF converters are dealing with digital signal rather than analog signal. Hope you put thing in proper perspective before making any comparison.

 
I am saying that listening via a better coax cable will not only incorporate the benefit of less jitter but also other effects such as the sonic signature of the cable itself. There is no way we can isolate the improvements and discern their causes when we listen to them. For example, QED coax is bright and transparent and VDH coax is sound natural and warm. But that tells us nothing about whether jitter is the culprit in making the sound less bright, muddy, unnatural, and etc. Of course, I am generalizing the sonic signature of QED and VDH coax cables. I am in no way implying or suggesting that they sound that way but am just using that as an example to illustrate my point.
 
Comparing cables of the same class, one with more jitter and the other with less, will help to isolate the comparison and allow us to hear the impact of jitter better.
 
Yeah, if you are assuming 100% efficiency rate in all the components used in an ideal world.

 
Quote:

Be careful, a comparison might not support accepted Dogma.
 
The Ears are lousy at reading specs and measurements.
 
This leaves the question, if your ears like toslink, what will you do?  Many people like toslink better but still go with coax just out of principle.

Dynabot I totally agree with you. At the end of the day, after reading all the specs, opinions, it is still up to our ears to decide, for our preferences and the synergy of our system still reign over everything else. We listen to audio to enjoy but at the same time are constantly looking for ways to make that listening a more enjoyable experience. Reading others' opinions are just a guide that points us to where to head towards but whether the findings of others are applicable to us there is no confirmation.
 
To conclude whether DI is an upgrade for iMac + StageDAC, the only way is the listen to it on your system yourself. One's conclusion may differ from another but that does not mean that one's opinion is correct or wrong because one is better at hearing and the other is not =)