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Old 31st March 2011, 05:08 PM   #231
exa065 is offline exa065  Canada
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Quote:
Originally Posted by soundcheck View Post
To my understanding you feed DACs I2S and not SPDIF. You gotta convert SPDIF at one point.

You can IMO achieve highest qualities with SPDIF if properly implemented.
Would you explain the need to involve SPDIF in the signal path? To use exaU2I USB to I2S interface you need a computer, USB cable, the exaU2I kit, short twisted pair wires and a DAC kit with an I2S input. The popular ES9018 DAC kits like the Buffalo DAC and the AckoDAC come with I2S inputs. There is plenty of information on their respective forums about using I2S. On our website we also provide the necessary information and schematics: www.exadevices.com > exaU2I > D.I.Y. Guide.
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Old 31st March 2011, 05:54 PM   #232
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Quote:
Originally Posted by exa065 View Post
Would you explain the need to involve SPDIF in the signal path? To use exaU2I USB to I2S interface you need a computer, USB cable, the exaU2I kit, short twisted pair wires and a DAC kit with an I2S input. The popular ES9018 DAC kits like the Buffalo DAC and the AckoDAC come with I2S inputs. There is plenty of information on their respective forums about using I2S. On our website we also provide the necessary information and schematics: www.exadevices.com > exaU2I > D.I.Y. Guide.
Read my earlier post, responding to jkenny. Than it might dawn on you, why SPDIF is on the table.

Finally it's all about your great, to me unacceptable high, 108ps jitter value on the output.

Anyhow. TP didn't make it on the first shot either.
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Old 31st March 2011, 06:08 PM   #233
jkeny is offline jkeny  Ireland
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Quote:
Originally Posted by soundcheck View Post
Read my earlier post, responding to jkenny. Than it might dawn on you, why SPDIF is on the table.

...........
I don't understand this either - I wasn't talking about SPDIF, I was talking about I2S. I agree with EXA why bring SPDIF into this - a fundamentally flawed technology?
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Old 31st March 2011, 06:30 PM   #234
exa065 is offline exa065  Canada
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Quote:
Originally Posted by soundcheck View Post
Read my earlier post, responding to jkenny. Than it might dawn on you, why SPDIF is on the table.

Finally it's all about your great, to me unacceptable high, 108ps jitter value on the output.

Anyhow. TP didn't make it on the first shot either.
You haven't answered my question. You just jitter around it. You propose huge unknown jitter as a remedy to quantified minuscule jitter that is proved to be within the jitter cancellation capability of ES9018.

exaU2I is not perfect and it will never be. See jkeny's signature. However for now it is the only device in its class. It creates the possibilities for DIY enthusiasts to compete with vey high-end $5,000 equipment. I mean equipment without SPDIF outputs.
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Old 31st March 2011, 07:12 PM   #235
Raj1 is offline Raj1  United Kingdom
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exa065, i think you're the first person to provide jitter specifications of a USB~i2s device. Given the topology used, I'd be very surprised if any of the other available DIY solutions can better this by a considerable margin as a standalone unit on jitter, and that's without taking into account the limited channel functionality of most other kit based products.

Last edited by Raj1; 31st March 2011 at 07:17 PM.
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Old 31st March 2011, 08:27 PM   #236
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The evaluation of the exaU2I continues and I have hooked up a old Buffalo32S DAC with a volumite control unit.
It was easy to connect - just follow the instructions for Buffalo´s www.exadevices.com > exaU2I > D.I.Y. Guide

As this is a Buffalo with 80Mhz clock it performs excellent at up to 192k/32bit.
If the clock was replaced with a 100MHz clock I expect even 384k/32bit should perform as well.

The following are my own calculations and valid for ALL ES9018 based DAC´s:
To run 352.8k/32bit with OSF enabled the clock need to be minimum 90.3168MHz.
To run 384k/32bit with OSF enabled the clock need to be minimum 98.304MHz.
If it is possible to disable the OSF a 80MHz clock will allow it to play 384k/32bit..

Last edited by RayCtech; 31st March 2011 at 08:31 PM.
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Old 1st April 2011, 04:10 PM   #237
Bunpei is offline Bunpei  Japan
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Quote:
Originally Posted by RayCtech View Post
The following are my own calculations and valid for ALL ES9018 based DAC´s:
To run 352.8k/32bit with OSF enabled the clock need to be minimum 90.3168MHz.
To run 384k/32bit with OSF enabled the clock need to be minimum 98.304MHz.
If it is possible to disable the OSF a 80MHz clock will allow it to play 384k/32bit..
Is this inductive rule set also applicable to your home-brew ES9018 DAC?
Exceptionally, can your home-brew DAC play 352.8 kHz and 384 kHz audio files without noises even on OSF enabled mode with 80 MHz oscillator?
Is the rule above also applicable to your deeply upgraded SDTrans?
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Old 1st April 2011, 05:27 PM   #238
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Quote:
Originally Posted by Bunpei View Post
Is this inductive rule set also applicable to your home-brew ES9018 DAC?
Exceptionally, can your home-brew DAC play 352.8 kHz and 384 kHz audio files without noises even on OSF enabled mode with 80 MHz oscillator?
Is the rule above also applicable to your deeply upgraded SDTrans?
Bunpei, your posting are far off topic this treads topic
Due to this you should post issues like this in your own SD card player tread..

The only issue I have had with 352.8k files on a SDTrans192 was when I was playing 352.8k and the next song had a different samplerate.
Due to the FPGA on the SDTrans192 do not reset the clocks when a song is finished (you might even take out the SD card) it continues to clock at 352.8k until a new song suddenly changes the samplerate and clocking.
This samplerate change I was able to hear as a short click noise until I changed the programming and cured that also.
For a long time I believed this was the noises you was talking about..

Bunpei - you may "jitter" around with your noise issues, but I do not think you will not get any more help due to that..

Last edited by RayCtech; 1st April 2011 at 05:33 PM.
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Old 1st April 2011, 07:22 PM   #239
elecon is offline elecon  Japan
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Since Exadevices have not yet delivered exaU2I to us here in Japan, all we can do is to excitedly watch developments on this thread :-) The issue being talked about "on topic" here is playback of high sampling files from 352.8kHz/24bit up to 384kHz/32bit into any Sabre ES9018 based DAC. Our own experience so far is to play 352.8kHz/24bit files using the SDTrans 192, and we are looking forward to playing 384kHz/32bit when we can receive the exaU2I. RayCtech has kindly informed us his own test results that:
Quote:
If it is possible to disable the OSF a 80MHz clock will allow it to play 384kHz/32bit..
I think this means that any ES9018 based DAC with an 80MHz clock will be able to noiselessly play up to 384kHz/32bit files regardless of the player being used (as long as the player is capable of playback) WITH OSF IS DISABLED, which then of course means that it will NOT be able to play 352.8kHz/24bit and above with the OSF being enabled (turned on).

It is probably interesting for us here in Japan to experiment more with our ES9018 based DACs and OSF disabled when using lower clock frequencies like 80MHz to play 352.8kHz/24bit files, until the exaU2I arrives and we also get to try 384kHz/32bit files as well :-)

I appreciate RayCtech telling us about his experience, and I think Bunpei's observations regarding experiencing noise during playback into ES9018 based DACs when clock frequency is too low (and OSF is enabled) is relevant for this thread too ;-) Point is of course to turn OSF off (disable).

Last edited by elecon; 1st April 2011 at 07:28 PM.
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Old 2nd April 2011, 12:06 PM   #240
Bunpei is offline Bunpei  Japan
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Quote:
Originally Posted by exa065 View Post
Would you explain the need to involve SPDIF in the signal path? To use exaU2I USB to I2S interface you need a computer, USB cable, the exaU2I kit, short twisted pair wires and a DAC kit with an I2S input. The popular ES9018 DAC kits like the Buffalo DAC and the AckoDAC come with I2S inputs.
As I am an "I2S fundamentalist", I completely agree with exa065's concept.

Quote:
Originally Posted by jkeny View Post
I agree with EXA why bring SPDIF into this - a fundamentally flawed technology?
The problem of intrinsic jitter in S/PDIF is well-illustrated in the following technical document,
Jullian Dunn, Audio Precision Application Note #5: Measurement Techniques for Digital Audio, Chapter 1. Jitter Theory.
(In this article, you can read technical details of J-Test signal measurement that is used in Stereophile measurement series and becomes very popular.)

However, employing I2S is just one element of a total audio system.
In my case, though I make efforts not to use S/PDIF, a vast amount of interfaces are S/PDIF in practical situations. Therefore we need to deal with S/PDIF well.

As eventually described in this message, around me, I know at least two actual examples that fit this description.
Quote:
Originally Posted by soundcheck View Post
You can IMO achieve highest qualities with SPDIF if properly implemented.
Total performance of DAC is not merely determined with signal interfacing method of I2S or S/PDIF.

Anyway, as much as we provide good performance of I2S interface used between transport and DAC in realized products, the number of people those who perceive the merit will increase.
I hope exaU2I will lead this trend.

Last edited by Bunpei; 2nd April 2011 at 12:13 PM.
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