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exaU2I - Multi-Channel Asynchronous USB to I2S Interface

That sounds great, but I'd still try to develop a multichannel WDM driver so users can play audio/video files with Windows 7 Media Center. With plugins like Media Browser or My Movies, users have a very nice interface for playing DVDs and Blu-rays. In my family, I don't think my wife and daughters would be as enthusiastic about our HTPC if they had to navigate to use the file or folder open function with MPC or VLC and navigate to the folder to find their movies. It's a lot nicer to browse the coverart, which is laid out alphanumerically.

7MC is also great for watching and recording live TV. It's too bad it falls short for playing music. I prefer JRMC for playing my ripped CDs, DVD-As, SACD and BD files (stereo and surround; 16- and 24-bit; 44.1 to 192 kHz). If only JRMC would include a 7MC plugin that would provide Theater View in 7MC.

Agreed, WDM driver is important. There is also an open source ASIO output plug-in which is supposed to work with Windows Media Center. It is unstable. I wish it will be fixed soon.
 
This kit should really make the most out of some 192Khz multichannel recordings I have. But I must admit that I am even more curious about the 384Khz, 32 bit setting. I actually have a master file at this sample rate (24 bits though) and I never got to hear it, so this might be my chance :).

The top frequency is actually 352.8 kHz. I don't have any 384 kHz files. Where would I find one?
 
This kit should really make the most out of some 192Khz multichannel recordings I have. But I must admit that I am even more curious about the 384Khz, 32 bit setting. I actually have a master file at this sample rate (24 bits though) and I never got to hear it, so this might be my chance :).

So to answer your question, I would have two uses for this: a) high resolution multichannel playback and b) high resolution digital crossover. Maybe the usb 3.0 version will be able of doing both of these at the same time :xfingers:

If your recordings are with Gypsy brass bands from Romania, man I would like to hear that.
 
If your recordings are with Gypsy brass bands from Romania, man I would like to hear that.

Actually it's some piano piece by Beethoven :)

I don't recall owning or even knowing about any gypsy/world music hi resolution recordings unfortunately. Anyway, as I am aware of, the better gypsy music recordings with bands from the Balkans are made abroad, in studios in the west.

I'll check if I can find the link with the 384Khz studio master file again.
 
Keep up the good work and give priority to the OSX drivers.

You can use Saracon (Weiss) to make the 384k/32bit test files.

One question / requirement:

To be able to play DXD in surround (352.8k/24bit in all channels) two of the USB cards need to used...

The two cards then needs to be identified as two separate identities to be able to map the surround channels to the correct USB card etc...
 
@exa065

1. Can the I2S bus of that board be slaved by a precision clock from the DAC side?

That would IMO be one of the key features. That's what most known PC interfaces and solutions are lacking.


2. Would you guys claim that all applications sound equal as long as the stream is delivered bit-perfect?


3. Would you claim that you managed (at least close) to 100% isolate from PC induced distortions?
 
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Hi,

to exa065:

what is the jitter of onboard XOs used for I2S generation?

What do you think about integrating Bluetooth (eg. cheap 2$ BT dongle from ebay) into your interface to use it (ofcourse only low sample rates) wirelessly? My fiend has a rather low cost home cinema system with Bluetooth sound gateway function - it is very convinient for laptop users.

Thanks
 
@exa065

1. Can the I2S bus of that board be slaved by a precision clock from the DAC side?

That would IMO be one of the key features. That's what most known PC interfaces and solutions are lacking.


2. Would you guys claim that all applications sound equal as long as the stream is delivered bit-perfect?


3. Would you claim that you managed (at least close) to 100% isolate from PC induced distortions?

1. No, the I2S bus needs to use one of the build in oscillators. We have your request on the to-do list for future versions. The built-in clocks are very good and we take care to minimize jitter. ES9018 based DACs are not going to benefit from the use of external reference clock. Other DACs will.

2. Yes, we claim that. What may be the concern here? Our philosophy is that the original bits should be delivered to the DAC without any processing. Every user should have the option to decide what make-up should be applied to the sound. We had already a discussion about alternatives ways to involve DSP. For now there are two options: player DSP plug-ins or ASIO VST hosts.

3. Yes. We use ASIO to completely bypass the Windows sound system. We have nothing to do with the Windows mixer, the Windows volume control, Kernel Streaming, Control Panel etc. Some people manage to put some of these technologies under control. It is hard to verify that all issues are resolved when Windows drivers are used. Our preference was to start with a clean solution and than to try to expand it gradually. This way we will know what is lost when compromises are made. The only harm that Windows can do is to be busy for too long and to have no spare CPU time for the player software.
 
1. No, the I2S bus needs to use one of the build in oscillators. We have your request on the to-do list for future versions. The built-in clocks are very good and we take care to minimize jitter. ES9018 based DACs are not going to benefit from the use of external reference clock. Other DACs will.

2. Yes, we claim that. What may be the concern here? Our philosophy is that the original bits should be delivered to the DAC without any processing. Every user should have the option to decide what make-up should be applied to the sound. We had already a discussion about alternatives ways to involve DSP. For now there are two options: player DSP plug-ins or ASIO VST hosts.

3. Yes. We use ASIO to completely bypass the Windows sound system. We have nothing to do with the Windows mixer, the Windows volume control, Kernel Streaming, Control Panel etc. Some people manage to put some of these technologies under control. It is hard to verify that all issues are resolved when Windows drivers are used. Our preference was to start with a clean solution and than to try to expand it gradually. This way we will know what is lost when compromises are made. The only harm that Windows can do is to be busy for too long and to have no spare CPU time for the player software.

Thx. Interesting marketing message you put up here.

Comments:
1.
Slaving your transport to a DAC has not been an actual request from my side
It was rather a remark about a key-issue (weakness) you'll find on the
majority of transports out there.


2.
Let me ask you why you bet on ASIO only.

"WASAPI exclusive" is the mode of choice for audiophile playback for quite some time on a Windows PC.

J. River MC even introduced the Wasapi Event-Style, which seems to be one of the reasons why JRMC got the lead in the "audiophile" Windows based player market.

Are there any plans from your side to support Wasapi exclusive/Wasapi Event-Style in the future?
(Though soundwise it shouldn't make any difference according to your earlier claims - since it would be as bit-perfect as ASIO)



Thx. Again.

Cheers
 
if it doesnt allow mcu based volume on sabre then its off my list i'm afraid. i dont see why it wouldnt though.

also i suggest you do some actual testing and listening, sabre is NOT uneffected by clock quality, async is not a magic bullet. it is less effected, but not uneffected in my experience. your module should be able to be clocked by the same clock as the dac
 
Thx. Interesting marketing message you put up here.

Comments:
1.
Slaving your transport to a DAC has not been an actual request from my side
It was rather a remark about a key-issue (weakness) you'll find on the
majority of transports out there.


2.
Let me ask you why you bet on ASIO only.

"WASAPI exclusive" is the mode of choice for audiophile playback for quite some time on a Windows PC.

J. River MC even introduced the Wasapi Event-Style, which seems to be one of the reasons why JRMC got the lead in the "audiophile" Windows based player market.

Are there any plans from your side to support Wasapi exclusive/Wasapi Event-Style in the future?
(Though soundwise it shouldn't make any difference according to your earlier claims - since it would be as bit-perfect as ASIO)



Thx. Again.

Cheers

1. Bottom line: Allowing use of external master clock is a good way to improve exaU2I when a non-reclocking DACs are used. It is not an issue if ES9018 is used.

2. WSAPI is widely accepted and can be bit-perfect. I couldn’t resolve two issues with WASAPI, maybe you can help me here:

I couldn’t find a way to make it to switch sample rates. If I have a playlist of several pieces with different sample rates and I want to avoid re-sampling, I have to stop playback and go to the control panel to reconfigure the WASAPI driver. ASIO can switch on the fly.

ASIO allows me to assign channels manually. This is needed for custom speaker configurations. I don’t know how this can be done with WASAPI in a bit-perfect way. I suspect that the Windows channel management is not audiophile-grade even with WASAPI. Most audiophiles are not affected by this because they listen to two channels.

I am betting only the first release of the devise on ASIO. I am planing to have native drives, including WASAPI. ASIO allows me to realize the full potential of the hardware, so it will be released first.
 
if it doesnt allow mcu based volume on sabre then its off my list i'm afraid. i dont see why it wouldnt though.

also i suggest you do some actual testing and listening, sabre is NOT uneffected by clock quality, async is not a magic bullet. it is less effected, but not uneffected in my experience. your module should be able to be clocked by the same clock as the dac

If three ESS90108 / 9012 boards are used (six channels), is it possible to use only one clock and eliminate clocks on other two DAC boards? Or do I need to use three clocks on three boards?
 
Could you tell us a little more how your ASIO driver will handle volume control?

If someone has an ES9018 based DAC, will they be able to use the ES9018's built-in volume control feature?

Is this implemented so you can control the volume of each channel AND have a master control?

There is no volume control in the ASIO specification. I also don't know how to send volume control commands for a DAC over an I2S interface. :confused:

ASIO capable players have built-in volume control. For example J. River has 64 bit volume control processing. The immediately available solution is the use the volume control of the player software.

In a high-end design volume control is done in the analog domain, after the DAC.

Let me turn the question around, what are the volume control solutions for your DAC kits?
 
There is no volume control in the ASIO specification. I also don't know how to send volume control commands for a DAC over an I2S interface. :confused:

ASIO capable players have built-in volume control. For example J. River has 64 bit volume control processing. The immediately available solution is the use the volume control of the player software.

In a high-end design volume control is done in the analog domain, after the DAC.

Let me turn the question around, what are the volume control solutions for your DAC kits?

I use analog 6 channel balanced relay controled volume. I do not care about volume that much. I am assuming you will have some graphic interface? Lets see this scenario, if this is going to work:

media player -------- Allocator (ASIO crossover) ---- USB to I2S 6 channel out ------- DACs x 3 -------- volume ----------amps--------speakers

It would be helpful to have some volume control, mabe not as master but something to adjust levels between channels. I guess I could do it in the Allocator, or individually on each DAC.

Do you see any problem with this configuration?
 
i suggest you do some actual testing and listening, sabre is NOT uneffected by clock quality, async is not a magic bullet. it is less effected, but not uneffected in my experience. your module should be able to be clocked by the same clock as the dac

Please check previous posts about the clock quality on the exaU2I kit.
Could you show us how you wire your I2S interface to your ES9018 DAC kit? If asinc is not working for you there must be something interfering.
 
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