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Old 30th October 2011, 02:44 PM   #901
exa065 is offline exa065  Canada
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Quote:
Originally Posted by AlanElsdon View Post
I am using ASIO on the cMP2.
Thanks, this is the recommended option.
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Old 30th October 2011, 10:58 PM   #902
rsdio is offline rsdio  United States
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Originally Posted by AlanElsdon View Post
the cMP2 by definition is running in 'Hog-Mode' - it is after all the only this left running on the pc!
That is not the definition of hog mode. Hog mode is a specific setting within CoreAudio that must be requested by the software that is feeding the audio device. You cannot obtain hog mode performance by simply running only one audio program, at least not unless that particular audio program specifically requests hog mode. For example, iTunes will never request hog mode, even if it is the only audio program running.

exa065 has responded with the specifics about the exaU2I, so you can trust him on the details. I just wanted to clarify the definition of hog mode.

P.S. Hog mode is part of CoreAudio, not ASIO.
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Old 1st November 2011, 03:16 AM   #903
exa065 is offline exa065  Canada
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Originally Posted by rsdio View Post
That is not the definition of hog mode. Hog mode is a specific setting within CoreAudio that must be requested by the software that is feeding the audio device. You cannot obtain hog mode performance by simply running only one audio program, at least not unless that particular audio program specifically requests hog mode. For example, iTunes will never request hog mode, even if it is the only audio program running.

exa065 has responded with the specifics about the exaU2I, so you can trust him on the details. I just wanted to clarify the definition of hog mode.

P.S. Hog mode is part of CoreAudio, not ASIO.
rsdio,
Your clarification is very punctual and precise as usual. But please, leave some breading space for the regular user. Alan's post is quite clear. He compares Apples to ...not oranges, cMP2. It's OK to use the term "Hog Mode" on both sides - cMP2 Windows ASIO vs. OS X. We understand that It stands for "Exclusive" or Single Client".
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Last edited by exa065; 1st November 2011 at 03:18 AM.
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Old 13th November 2011, 03:27 PM   #904
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I have some questions regarding performance claims for the Exa USB interface (if not better than). On this thread you claim that this device has a jitter level as low as any other USB interface. Since I do not see any real jitter measurements at your site, I am wondering what these claims are based on? Certainly an analysis of the analog output of an ESS 9018 based DAC is not very indicative of the jitter at the DACs input-considering that most implementations of the ESS 9018 utilize the DAC in asynchronous mode, re-clocking everything with its onboard ASRC.

If your only methodology to test for jitter artifacts is through the analog output of the attached DAC, I would recommend running the ESS 9018 in synchronous mode (providing the masterclock from I2S from the Exa), and publishing the results on the analog output, this approach would reveal something real about the jitter performance of the Exa.

Another spec which might reveal something relevant about the potential performance of the Exa would be to let potential purchasers know what oscillators are used on the board, and what their phase noise spec at 10 Hz might be. Right now, for a device which costs $400, there seems to be a paucity of real information about how well it really can perform. Of course, as long as you are confident in the design, it will be to your advantage to reveal some more relevant technical information.
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Old 13th November 2011, 05:15 PM   #905
ljames is offline ljames  Canada
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I am thinking if can use the board with the DAC inside my Sony SCD-777ES or Korg MR2000S recorder to play DSD files.
The SCD-777ES has internal clock, so I wonder if the board can disable build-in clock and using external clock?
For the Korg, it uses CS4398, it has DSD input pins but the mode setting is by program, so I double it will be easy to deal with. It does look like it can using external clock though.
Can somebody help?
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Old 14th November 2011, 11:08 AM   #906
exa065 is offline exa065  Canada
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Originally Posted by ljames View Post
I am thinking if can use the board with the DAC inside my Sony SCD-777ES or Korg MR2000S recorder to play DSD files.
The SCD-777ES has internal clock, so I wonder if the board can disable build-in clock and using external clock?
For the Korg, it uses CS4398, it has DSD input pins but the mode setting is by program, so I double it will be easy to deal with. It does look like it can using external clock though.
Can somebody help?
Hi ljames, unfortunately it is impossible to use exaU2I with an external clock.
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Old 14th November 2011, 11:54 AM   #907
exa065 is offline exa065  Canada
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Originally Posted by barrows View Post
On this thread you claim that this device has a jitter level as low as any other USB interface.
barrows, I've never said that. Of course USB devices are not born equal.
Quote:
Originally Posted by barrows View Post
Since I do not see any real jitter measurements at your site, I am wondering what these claims are based on?
Please read the previous posts in this thread. This question has been answered many times.
Quote:
Originally Posted by barrows View Post
Certainly an analysis of the analog output of an ESS 9018 based DAC is not very indicative of the jitter at the DACs input-considering that most implementations of the ESS 9018 utilize the DAC in asynchronous mode, re-clocking everything with its onboard ASRC.
exaU2I is designed and optimised for use with ES9018. Previous posts discuss the jitter tolerance of this DAC. It doesn't make sense to turn off one of the most important features of the DAC - the jitter suppression.

Quote:
Originally Posted by barrows View Post
Another spec which might reveal something relevant about the potential performance of the Exa would be to let potential purchasers know what oscillators are used on the board.
Again, in the recommended configuration the performance of the onboard clocks has minimal impact on the DAC performance because the I2S stream is relocked with the 100 MHz master clock on the DAC board.

barrows, I can understand that you are unsatisfied. From the point of view of traditional designs it will make sense to use the most expensive clocks, resistors, Teflon insulators etc... We are not interested to compete in this area. We rely on good overall integrity of the design and we don't believe that dollars should be thrown at every component without proven impact on the end result. These of course have a "feel good" effect.

exaU2I is an alternative device. You've tried the best of the main stream. If you are still looking for more, you need to try something different. Try exaU2I, I can offer you a money back warrantee. Your risk is the shipping cost. If you decide to keep it, change the clocks, apply independent power supplies, put extra capacitors, remove the GMRs. Enjoy the DIY journey and share the results with us.
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Old 14th November 2011, 12:56 PM   #908
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Thread moved to vendor's own area.
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Old 15th November 2011, 04:45 AM   #909
qusp is offline qusp  Australia
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sabre isn't as immune as you seem to think it is

glad you have your own forum finally, good luck
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Old 15th November 2011, 05:35 AM   #910
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Default Exa...

So I guess you are confirming my fears that the Exa is really not optimized to produce the lowest possible jitter.

"exaU2I is designed and optimised for use with ES9018. Previous posts discuss the jitter tolerance of this DAC. It doesn't make sense to turn off one of the most important features of the DAC - the jitter suppression."

Some listeners (including ESS designer Dustin) have found that they prefer the sound of the ESS 9018 with synchronous clocking, and (hence) the ASRC and DPLL disabled. Of course, to get the best performance in this mode requires a low jitter source. I personally prefer the ESS 9018 in synchronous clocking mode, as the sound is just a little more natural in regards to timbre without the ASRC.

To suggest that using very low phase noise oscillators is an unnecessary expense appears a little odd to me... Every digital engineer whom I have any respect for has stressed the importance of low phase noise oscillators (running on clean isolated power supplies) for producing the best possible sound.
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