exaU2I - Multi-Channel Asynchronous USB to I2S Interface

[exa065]

Note taken. We will do better next time.

[exa065]

I've just moved the discussion about using exaU2I with the Twisted Pear SPDIF Transceiver to a new thread: exaU2I Connected to the Twisted Pear SPDIF Transceiver. This is a brand new application for exaU2I and it deserves its own space.

[kschiu]

Just curious, with the EXAU2I, assuming the same software is used, does the PC matter any more? i.e. AMD vs Intel Cores vs Intel ATOM, slow vs fast CPU, quality of the USB port/cable/length etc?

[exa065]

Originally Posted by kschiu

Just curious, with the EXAU2I, assuming the same software is used, does the PC matter any more? i.e. AMD vs Intel Cores vs Intel ATOM, slow vs fast CPU, quality of the USB port/cable/length etc?

Depend who you ask. Theoretically the PC etc. doesn't matter anymore. In my personal experience, if the CPU is fast enough to keep up with the data stream, and the PC power is within the industry standard norms, the sound is not affected by the computer hardware. I've seen situations when the USB power is below 4.4V, and I've seen USB controllers that are not doing their job. In general, an average PC is not affecting the sound quality. I've done blind tests of exaU2I, and so far I haven't met an audiophile that can reliably identify the sound of different computers or USB cables.

Many will disagree, and I respect their opinions. I am always interested to participate in listening tests, and to experience different ways of doing high-end audio.

Regards,
exa065

[exa065]

Here are exaU2I /ES9018 DAC noise floor measurements with and without ground isolation. Both measurements are taken with the exaU2I USB cable connected to a standard PC: no special power supplies or filters, regular hard drive, I7 CPU, standard USB 2.0 controller. The exaU2I is powered by the USB cable. For the second measurement the USB ground is connected to the DVCC DAC ground with 1MOhm resistor.

You can clearly see the benefit of using Galvanic isolation. It is impossible to achieve this level of common noise suppression with USB and SATA filters, audiophile grade USB controllers, or by "cleaning" computer power lines.

[kschiu]

thanks George.

that's exactly what I want to hear. Getting an audiophile grade PC costs a fortune after I did some research. linear power supply, fanless cooling with Intel cores ... special USB cards ... silver SATA and USB cables ... no thanks. I thought the EXA is to eliminate all of those requirements.

But then, what's the minimum requirement on the CPU? Is an ATOM fast enough?

[crazikid]

Originally Posted by kschiu

thanks George.

that's exactly what I want to hear. Getting an audiophile grade PC costs a fortune after I did some research. linear power supply, fanless cooling with Intel cores ... special USB cards ... silver SATA and USB cables ... no thanks. I thought the EXA is to eliminate all of those requirements.

But then, what's the minimum requirement on the CPU? Is an ATOM fast enough?

yes i'm pricing a PC ATM.. it can add up very fast depending on which specs you choose.

how much memory? sorry if you have mentioned this earlier.

[exa065]

Our ASIO drivers are very efficient. An Atom CPU can support 384kHz / 4 channels at about 40% load. I recommend i5 CPU and 4GB memory to be able to handle audio and HD video.

[RayCtech]

Originally Posted by exa065

Our ASIO drivers are very efficient. An Atom CPU can support 384kHz / 4 channels at about 40% load.

Atom CPU running Linux and 384kHz / 2 channels is about 1 - 2% load.
I do not want to think of what evils the 39% in difference are causing.
So I am waiting for ALSA drivers to use the exaU2I with MPD

[exa065]

Perhaps the Foobar visualizations, I don't have an Atom net-book handy to redo the test.
(When I come to see you later this month, we can compare apples with apples )