Asus Essence One Headphone Amp/DAC (CeBIT 2011) - Page 114

Quote:

Originally Posted by Whit3Rav3n 

Yes but that is with analog signal, these interfaces would be connected via digital cable to the computer.

And with an analog cable to each other. Since the digital cables are not connected to exactly the same point of the computer, there will be a small potential difference between the ground of the interfaces, resulting in common mode noise on the analog cable.

Quote:

Originally Posted by Whit3Rav3n 

since the resistance differences are so small that it would be really difficult to even measure it. It is far more likely that the noises come from ripples in the power supply caused by the pc components.

The resistances might be small, but they are not zero. Also, the ground currents from some devices in a desktop PC are huge, and the amount of noise that was measured is equivalent to only a small voltage (-92 dBA relative to 2 Vrms is only 50 uV A-weighted noise voltage).

A differential amplifier does not eliminate power supply ripples. Nor does the power supply theory explain why the noise is there only if one sound card is recording the output of another, without using a differential amplifier.

Also, if I connect the line output of both sound cards to two inputs of an external (not grounded) amplifier, and I turn up the volume on the amplifier, I can hear the computer noise. But unplugging the other sound card (not the one that is selected as input) makes the noise go away completely.

The only plausible explanation to all of the above is a ground potential difference between the sound cards.

We have knowledgeable people here 

Keep up the good work guys!

ASUS, please address some of these issues if you want to go further into the audio realm.

Tim

Quote:

Originally Posted by stv014 

 

And with an analog cable to each other. Since the digital cables are not connected to exactly the same point of the computer, there will be a small potential difference between the ground of the interfaces, resulting in common mode noise on the analog cable.

 

 

The resistances might be small, but they are not zero. Also, the ground currents from some devices in a desktop PC are huge, and the amount of noise that was measured is equivalent to only a small voltage (-92 dBA relative to 2 Vrms is only 50 uV A-weighted noise voltage).

 

A differential amplifier does not eliminate power supply ripples. Nor does the power supply theory explain why the noise is there only if one sound card is recording the output of another, without using a differential amplifier.

Also, if I connect the line output of both sound cards to two inputs of an external (not grounded) amplifier, and I turn up the volume on the amplifier, I can hear the computer noise. But unplugging the other sound card (not the one that is selected as input) makes the noise go away completely.

The only plausible explanation to all of the above is a ground potential difference between the sound cards.

Yes but then they are external interfaces and they are also grounded to the outlet so the real potential difference would be between pc and outlet.

Also when considering voltage drop because of current the only current that matters is the one that actually flows from one device to the other. Every other current caused by other components just flows past and is not doing anything. So when picking for example two usb ports next to each other they share the some ground wire and you won´t get huge currents flowing between the ground pins of two usb ports.

Also you have to consider that if you use internal sound cards there can be noise problems caused by the pic-e ports, two devices can interfere with each other because of the shared channels on pci-e causing higher noise and jitter. This is a not uncommon problem in studio pc-s.

I have another question for Asus, as I had somebody ask me about the following:

At the download section of the Asus one normal version, their is a windows 8 driver, while at the download section for muses version (& the plus version), there is non to download!

I know I can get it from the E1 normal version and install the driver on Windows 8 for the Muses edition, or am I wrong?

Proof:

Quote:

Originally Posted by Whit3Rav3n 

Yes but then they are external interfaces and they are also grounded to the outlet so the real potential difference would be between pc and outlet.

The E-Mu 0404 is not grounded to the outlet, as far as I know, and even if it was, it would not completely eliminate the problem, and would potentially create others.

The grounding in a desktop PC is not designed with audio applications in mind, and multiple ground paths are possible between the PSU, the motherboard, the case (to which almost everything is grounded in some way), and the various components. As I already explained earlier, the noise voltages are small, so it is not necessary for huge currents to flow between the ports, but a fraction of them will take that path, and even that is enough for the <0.1 mV noise measured.

Quote:

Originally Posted by Whit3Rav3n 

Also you have to consider that if you use internal sound cards there can be noise problems caused by the pic-e ports, two devices can interfere with each other because of the shared channels on pci-e causing higher noise and jitter.

These again would not explain why the differential amplifier eliminates the noise.

Anyway, it looks like this discussion is a waste of time (not to mention getting really off-topic in this thread), as I know already well enough that computers have grounding issues, and you just keep arguing, and arguing, and arguing endlessly, no matter what, and ignore any evidence shown. So, I consider this closed and will not post further replies, or bother reading what you write. You can discuss it with others who have more time at Sound Science if you want.

Has any of you tried to message ASUSXONAR in order to obtain a reply?

Should be fixed shortly. Yes use the E-One driver, it's exactly the same. 

Quote:

Originally Posted by turokrocks 

I have another question for Asus, as I had somebody ask me about the following:

At the download section of the Asus one normal version, their is a windows 8 driver, while at the download section for muses version (& the plus version), there is non to download!

I know I can get it from the E1 normal version and install the driver on Windows 8 for the Muses edition, or am I wrong?

 

Proof:

 

 

 

Quote:

Originally Posted by cssarrow 

We have knowledgeable people here 

 

Keep up the good work guys!

 

ASUS, please address some of these issues if you want to go further into the audio realm.

 

Tim

We have been looking into this. During development we were given a choice of four different filter options (not all at the same time obviously). The current filter was chosen and it favors high sampling rates (88KHz upwards), the side effect being the sharp cut-off for lower sampling rates.

We're working with the developer and discussing a new filter that is less aggressive at lower sampling rates. There are side effects to every choice, but we'll try and do something that is more universal.

Thank you Asus.

Before Hi Gain:

After Low gain :

One for the gang

Ow, have you received the proper muses now?

Bad news guys, the Headphone volume knob of the new unit is making a scratch sound!!!!  something is in friction/contact....What is going on...?

The old unit's volume knob is smooth but got his heavy feeling while turning, but the one in the new unit is much "Loosy"...

Quote:Originally Posted by turokrocks 

Bad news guys, the Headphone volume knob of the new unit is making a scratch sound!!!!  something is in friction/contact....What is going on...?

The old unit's volume knob is smooth but got his heavy feeling while turning, but the one in the new unit is much "Loosy"...

That would be the sound of broken.

Quote:

Originally Posted by Sk1n5 

Quote:Originally Posted by turokrocks 

Bad news guys, the Headphone volume knob of the new unit is making a scratch sound!!!!  something is in friction/contact....What is going on...?

The old unit's volume knob is smooth but got his heavy feeling while turning, but the one in the new unit is much "Loosy"...

 

 

 

That would be the sound of broken.

Broken indeed, broken luck,  & hope.

Guys I really love my Asus, the sound is like nothing!!  but what will I do next? I am totally lost.

Quote:

Originally Posted by turokrocks 

Broken indeed, broken luck,  & hope.

 

Guys I really love my Asus, the sound is like nothing!!  but what will I do next? I am totally lost.

Does the volume control work?  If it works (vol up and down) the scratching sound may be the volume knob rubbing on the front panel, at least it sounds like that on your video.  Pull the knob out a bit until you don't hear the scratching.