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exaU2I - Multi-Channel Asynchronous USB to I2S Interface

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#1,343
Hi Exa065, I am experimenting with using my EXAU2I board with Jplay. It seems that 'kernel streaming mode' is considered the best way to get data to the board, but it seems the current EXA driver does not support this, so I am using the ASIO interface.

Is there any chance to get an updated driver that would support kernel streaming?

- r.
 
#1,345
rab28 said:
Hi Exa065, I am experimenting with using my EXAU2I board with Jplay. It seems that 'kernel streaming mode' is considered the best way to get data to the board, but it seems the current EXA driver does not support this, so I am using the ASIO interface.

Is there any chance to get an updated driver that would support kernel streaming?

- r.
Click to expand...


Well, this is one reason why we gave up on making devices for the DIY community. We tried really hard, and we couldn't explain that ASIO is 10,000 times better than kernel streaming.

We don't have kernel streaming because we don't like it. We want you to get away from trying to improve the Windows kernel, the Windows sound system, to improve the accuracy of Windows timers, interrupts, noise sources, power supplies etc. We believe all this is hopeless, curing the symptoms, not the root cause. The solution that we offered with the exaU2I was different, it just goes by a different logic.

Surprisingly it was easier to win this argument on the consumer market with audiophiles. They don't have the technical background, but they believe their years, not what rumors say "is considered the best way to get data to the board".
 
#1,346
smooth dancer said:
http://www.hifisentralen.no/forumet.../187437d1362849236-buffalo-iii-gwimg_1708.jpg

Here is my solution. Placid hd feeding usb on Exa. Great improvement in sound.
Click to expand...

Could I ask you for a simple measurement? I assume your exaU2I is installed in your system, all power supplies are connected, the DAC is connected and the system can play music. Plug an USB cable in the exaU2I and unplug the other end of the USB cable from the computer.

Can you measure (approximately) the resistance between the ground on the far end of the USB cable and the ground of the line RCA (or XLR) cable that goes to your power amplifier?
 
#1,347
#1,348
exa065 said:
Well, this is one reason why we gave up on making devices for the DIY community. We tried really hard, and we couldn't explain that ASIO is 10,000 times better than kernel streaming.

We don't have kernel streaming because we don't like it. We want you to get away from trying to improve the Windows kernel, the Windows sound system, to improve the accuracy of Windows timers, interrupts, noise sources, power supplies etc. We believe all this is hopeless, curing the symptoms, not the root cause. The solution that we offered with the exaU2I was different, it just goes by a different logic.

Surprisingly it was easier to win this argument on the consumer market with audiophiles. They don't have the technical background, but they believe their years, not what rumors say "is considered the best way to get data to the board".
Click to expand...

I agree ASIO is a good solution, but according to Microsoft, you should also get bit perfect performance with kernel streaming. Just not with as low latency, which is critical for monitoring while recording (and is not your target market).

Here's the problem with ASIO - if you try to play surround recordings with Windows Media Center (or anything based on the Windows Media Player), you only get stereo playback. These apps only use the number of channels available in the device's settings in the Windows Control Panel.

That's fine for audiophiles that only listen to stereo recordings, but it's unfortunate for people that use their htpc to listen to music and watch TV. If I connect high end components, like your product, to my PC, I want to use it for all audio playback.

I'd probably use ASIO with compatible apps like J.River Media Center, but I'd like another multichannel wdm driver for those that don't. Ideally, I'd like to have a native USB Audio Class 2.0 driver for Windows.

If Microsoft were to provide a native USB Audio Class 2.0 driver, would you come back to the DIY market?

Sent from my Nexus 7 using Tapatalk
 
#1,349
exa065 said:
Could I ask you for a simple measurement? I assume your exaU2I is installed in your system, all power supplies are connected, the DAC is connected and the system can play music. Plug an USB cable in the exaU2I and unplug the other end of the USB cable from the computer.

Can you measure (approximately) the resistance between the ground on the far end of the USB cable and the ground of the line RCA (or XLR) cable that goes to your power amplifier?
Click to expand...


Hi George

I can measure later today
 
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#1,350
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#1,352
leifchristensen said:
your solution?
that photo is from my dac and I was the one that first gave the tip to the Norwegian DIY community documented with this exact picture
(even my handwriting with pencil on the rear panel !)
the most significant upgrade to any usb dac imo
best
Leif
Click to expand...



Wrong choice of words from me. You are correct Leif, and it was thank to you who gave me the tip, that I have a very good sounding dac with Exa today.

Instead of opening my dac and take a pic, I borrowed your exellent pic which show how it can be done (and exactly how I did it too).

Hope this clear things up. Not my intension to take credit for what you have done, and I must say that you impress me in your never ending search for better sound.
 
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#1,355
Hi Tommy,

It is not a good thing. You should measure infinitely high resistance between the PC ground and the DAC ground. By changing the power source for the USB chip you have introduced a connection between the computer ground and the analogue ground. This connection acts as antennae for the high-frequency computer noise. This common noise travels freely to your DAC and amplifiers. Your exaU2I is like not having the ground isolation.



Try to use dedicated transformer, power supply etc. for the 5V supply that goes to the USB. Keep the grounds separate.
 
#1,357
exa065 said:
Hi Tommy,

It is not a good thing. You should measure infinitely high resistance between the PC ground and the DAC ground. By changing the power source for the USB chip you have introduced a connection between the computer ground and the analogue ground. This connection acts as antennae for the high-frequency computer noise. This common noise travels freely to your DAC and amplifiers. Your exaU2I is like not having the ground isolation.



Try to use dedicated transformer, power supply etc. for the 5V supply that goes to the USB. Keep the grounds separate.[/QUOTE



Edit: I think everything is ok George ( based on what you write above ) or ? ( see my answer to Leif in the next post )


I am using an dedicated transformer and psu ( placid hd )and the sound is great. Here is a bad pic
An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.
Click to expand...
 
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