[Happy Camper]

I understand the computer environment and it's impact on data. My question is in using a single USB output dedicated only to the audio stream. Can it be done with commercial computers or can it be built? Please give me some education on the reasons streamers are becoming more of the direction for digital listening vs computers. Or am I incorrect in my impression and straighten me out. I want to learn.

 

[chewy4]

I'm a little confused with your first question. What do you mean by this? The USB output can only be used for audio data? The only thing the computer can do is output data to that USB output?
 
As for streamers, I would think people use these just for convenience. The audio is still coming from a computer, it's just a convenient way to get it into another room from the computer.

 

[astrallite]

USB is no different than using HDMI from your video card since both of them are electrical and exposed to the same interferences (ground loops, EMI, radio waves, etc). Although with HDMI video and audio are clocked synchronously so you aren't as likely to get lip sync issues.
 
Only optical (digital toslink) would really be free electrical-related interference. However, all computers have USB and not all have optical ports, which is why USB-based streamers are popular. It's simply a more accessible interface, not necessarily the cleanest one.

 

[khaine1711]

Quote:

I understand the computer environment and it's impact on data. My question is in using a single USB output dedicated only to the audio stream. Can it be done with commercial computers or can it be built? Please give me some education on the reasons streamers are becoming more of the direction for digital listening vs computers. Or am I incorrect in my impression and straighten me out. I want to learn.

The thing with computer "purity" is overblown - or most authors of those articles are using Pentium 3 computer running from a cheap no name PSU with extremely high ripple. The only problem with PC as source is "dirty power". Also, there are electrical interference from the computers, and there's several ways around this. 
 
Use a Dac which the USB input draw power from its own transformer, and has galvanic isolation. If that is not possible, use a USB with split power and data, then feed the 5V with a high quality PSU, and bend/remove the 5V pin from the Data side. Use optical - has its own problems, but always free from electrical noise.
 
I don't think PC can have any "impact" on data, when it's bit-perfect. We're talking about Intel/AMD rig that can calculate hundreds time more than an audio stream can ever demand here. Timing and latency are pretty moot, especially with Async. You don't see Steve of Empirical Audio requires a i7 3770 OC to 5GHZ to maintain perfect data with his Offramp, do you? 

 
Personally I'm using a PC I built myself. Spec is pretty high back then (i5 3570k OC-ed, 7970 Lightning and stuff). And I don't have much problem with electrical interference. I only encountered such problem lately with a new dac (Eximus Dp1), of which USB input doesn't have any isolation. It's quite funny actually, plug a USB stick into the same hub, transfer data and you can literally "hear" the data flowing 

.
 
My main dac is a lampi, the USB of which is an Xmos with galvanic isolation, tapped from its own transformer. No matter which USB ports I plug that into, I hear no noise/interference (yes even into the back side, among a crap load of power/LAN spider nests of cables).
 
I think that's as good as it gets. Now there is only one company that does optical isolation to get rid of noise. Theoretically that's the perfect solutions/implementations but I don't have $40K to blow to check if that is a big improvement or not.

 

[Happy Camper]

Chewy,

The USB bus is shared out of the computer and so anything connected to the bus has an influence. The question I have is can you assign the audio output to one USB port, making it dedicated for audio use only or would you have to break (electrically) the bus terminals off so that only a single port was on it? The purpose would be to minimize any impact on the audio data. Or as is mentioned, is it a non issue.

Thanks for the efforts and content gang.

 

[Steven Stone1]

On my Mac Pro tower there are several separate USB Busses. I've attached a pic to demonstrate:
 
 

You could also add an additional separate PCIe card with USB 2.0 or 3.0 that could serve as your "dedicated" audio USB.

 

[Currawong]

I reckon the main thing is that whatever is powering the USB input have clean power. If the USB is powered inside the DAC, then using a USB cable with the 5V line cut is 95% of fixing any issues. If the USB on your DAC uses bus-power, then using an Aqvox or similar power supply for that will take care of that. Then using a good player on your computer that can switch sample rate output to match the track is the last important thing. Playing around with computer up-sampling and other stuff is at the last 1% in my experience.

 

[Eddie Q]

You may want to check out http://www.computeraudiophile.com/section/c-p-s-489/

 

[conquerator2]

Quote:

Chewy,

The USB bus is shared out of the computer and so anything connected to the bus has an influence. The question I have is can you assign the audio output to one USB port, making it dedicated for audio use only or would you have to break (electrically) the bus terminals off so that only a single port was on it? The purpose would be to minimize any impact on the audio data. Or as is mentioned, is it a non issue.

Thanks for the efforts and content gang.

 
I only had static noise issues with hat when the DAC drew power directly from the USB ports. As long as it took it from a wall socket, there was no interference problem at all.
Getting an external power supply/purifier and a DAC that can use it might help too

 

[JWahl]

Quote:

The thing with computer "purity" is overblown - or most authors of those articles are using Pentium 3 computer running from a cheap no name PSU with extremely high ripple. The only problem with PC as source is "dirty power". Also, there are electrical interference from the computers, and there's several ways around this. 
 
Use a Dac which the USB input draw power from its own transformer, and has galvanic isolation. If that is not possible, use a USB with split power and data, then feed the 5V with a high quality PSU, and bend/remove the 5V pin from the Data side. Use optical - has its own problems, but always free from electrical noise.
 
I don't think PC can have any "impact" on data, when it's bit-perfect. We're talking about Intel/AMD rig that can calculate hundreds time more than an audio stream can ever demand here. Timing and latency are pretty moot, especially with Async. You don't see Steve of Empirical Audio requires a i7 3770 OC to 5GHZ to maintain perfect data with his Offramp, do you? 

 
Personally I'm using a PC I built myself. Spec is pretty high back then (i5 3570k OC-ed, 7970 Lightning and stuff). And I don't have much problem with electrical interference. I only encountered such problem lately with a new dac (Eximus Dp1), of which USB input doesn't have any isolation. It's quite funny actually, plug a USB stick into the same hub, transfer data and you can literally "hear" the data flowing 

.
 
My main dac is a lampi, the USB of which is an Xmos with galvanic isolation, tapped from its own transformer. No matter which USB ports I plug that into, I hear no noise/interference (yes even into the back side, among a crap load of power/LAN spider nests of cables).
 
I think that's as good as it gets. Now there is only one company that does optical isolation to get rid of noise. Theoretically that's the perfect solutions/implementations but I don't have $40K to blow to check if that is a big improvement or not.

 
Quote:

Chewy,

The USB bus is shared out of the computer and so anything connected to the bus has an influence. The question I have is can you assign the audio output to one USB port, making it dedicated for audio use only or would you have to break (electrically) the bus terminals off so that only a single port was on it? The purpose would be to minimize any impact on the audio data. Or as is mentioned, is it a non issue.

Thanks for the efforts and content gang.

 
Continuing my thoughts from another thread since this one is more topic appropriate...  I noticed a reasonable subjective quality improvement when adding Fidelizer to my system.  My Self Built PC specs are as follows:
 
Core I7 2600k
Corsair Vengeance Ram 8 Gb
MSI Z68 motherboard
Samsung SSD (Boot drive, audio not stored on)
Kingwin platinum 1000w PSU
2 x 2Tb WD HDD's
 
JRiver Media Center 18 + Fidelizer (recently added)
Resonessence Concero DAC
Burson Soloist Amp
Sennheiser HD800
 
Of note also is that my network adapter is run off of USB so it could just be that my system is prioritizing the constant network traffic over audio.  Also USB mouse and keyboard are gaming models that, I believe, have higher than average USB polling rates.  Whatever it was, something was clearly siphoning traffic priority from the Audio Stream before.

 

[JWahl]

Quote:

I understand the computer environment and it's impact on data. My question is in using a single USB output dedicated only to the audio stream. Can it be done with commercial computers or can it be built? Please give me some education on the reasons streamers are becoming more of the direction for digital listening vs computers. Or am I incorrect in my impression and straighten me out. I want to learn.

And to answer your original question this would probably be your best bet..
 
http://www.sonore.us/SOtM.html
 
Scroll down to their PCI card.  Now I can't from personal experience say if it makes a difference or not, but it sounds like what you're looking for.  

 

[Logistics]

Only thing about Optical is it still has to be converted from digital, then back to regular digital before its converted to analog. Some dont approve of all this conversion going on.

 

[conquerator2]

Quote:

 
 
Continuing my thoughts from another thread since this one is more topic appropriate...  I noticed a reasonable subjective quality improvement when adding Fidelizer to my system.  My Self Built PC specs are as follows:
 
Core I7 2600k
Corsair Vengeance Ram 8 Gb
MSI Z68 motherboard
Samsung SSD (Boot drive, audio not stored on)
Kingwin platinum 1000w PSU
2 x 2Tb WD HDD's
 
JRiver Media Center 18 + Fidelizer (recently added)
Resonessence Concero DAC
Burson Soloist Amp
Sennheiser HD800
 
Of note also is that my network adapter is run off of USB so it could just be that my system is prioritizing the constant network traffic over audio.  Also USB mouse and keyboard are gaming models that, I believe, have higher than average USB polling rates.  Whatever it was, something was clearly siphoning traffic priority from the Audio Stream before.

 
So.... did you purposely leave out the GFX? 

  
I am just curios 

 

[JWahl]

Quote:

 
So.... did you purposely leave out the GFX? 

  
I am just curios 

Silly me. 

 Just using a stock MSI Radeon 7970.  I guess I must have forgotten it since it's less relevant for audio purposes.

 

[conquerator2]

Quote:

Silly me. 

 Just using a stock MSI Radeon 7970.  I guess I must have forgotten it since it's less relevant for audio purposes.

Still a fine GFX I would say