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Old 10th April 2011, 12:35 AM   #301
exa065 is offline exa065  Canada
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Quote:
Originally Posted by SunRa View Post
I have a board in the making that should stretch the limits of AK4396
SunRa,
Your project is very interesting for all of us on this thread. You are venturing into uncharted territory. exaU2I has never been tested with AK4396.

The more you clean and simplify the signal path, the more the sound will open up in terms of details and realism. There is no end to it. At this point you are enjoying the benefits of excellent player, driver and interface. Once you finish the DAC you may feel compelled to perfect the amplifiers, the speakers and eventually the room .
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Old 10th April 2011, 03:49 PM   #302
SunRa is offline SunRa  Romania
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Well I definitely feel the need of a speaker upgrade after this last week-end!

Now I've discovered an odd thing when playing with the U2I. I have two files at 352.8Khz 32 bits and I didn't even considered playing these in foobar without a sample rate converter. Now I accidentally played one in foobar and guess what, I was hearing music. Now how on earth is this possible?? AK4396 can play higher sampling rates?? How? I am all settled regarding the 32bits matter, I am sure the chip is ignoring the last bits. Still, what about the sampling rate?

Now here's another funny thing: I also have some 24 bit / 352.8 files. And these are playing also, only that it's also coming with a terrible hiss noise. The only difference I get in Foobar is that when playing the 32bit ones it says PCM (floating point) followed by bitrate and sampling rate.

Any ideas on what is happening?
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Old 10th April 2011, 04:42 PM   #303
exa065 is offline exa065  Canada
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Quote:
Originally Posted by SunRa View Post
Well I definitely feel the need of a speaker upgrade after this last week-end!

Now I've discovered an odd thing when playing with the U2I. I have two files at 352.8Khz 32 bits and I didn't even considered playing these in foobar without a sample rate converter. Now I accidentally played one in foobar and guess what, I was hearing music. Now how on earth is this possible?? AK4396 can play higher sampling rates?? How? I am all settled regarding the 32bits matter, I am sure the chip is ignoring the last bits. Still, what about the sampling rate?

Now here's another funny thing: I also have some 24 bit / 352.8 files. And these are playing also, only that it's also coming with a terrible hiss noise. The only difference I get in Foobar is that when playing the 32bit ones it says PCM (floating point) followed by bitrate and sampling rate.

Any ideas on what is happening?
SunRa, we need to investigate.

The most suspicious issue is the floating point. The exaU2I ASIO driver supports only Integer formats. Can you provide screen-shots of Foobar reporting floating point? Is it reporting floating point source file or floating point output? I would like to see the Foobar Status Bar and the media properties pane during playback. Please verify that there are no DSP plugins loaded. Check also the settings window - Output Settings. When ASIO output is selected the drop-down for output format should be blank and disabled. The ASIO driver takes over the control of the output format.

You may be discovering something here. If your Foobar configuration is correct and there is no implied re-sampling than.... your DAC may be more capable than expected.

We also experienced noise and distortion in some modes during our initial tests with ES9018. I would like to play the same 24 bit / 352.8 files with my DAC. I should test with the exact same Foobar settings as you. This will allow us to narrow down the root cause of the noise problem.

Cheers,

exa065
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Old 10th April 2011, 05:32 PM   #304
SunRa is offline SunRa  Romania
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The funny thing is that when building this DAC I researched the white papers released by Anagram regarding their technology used in Cambridge CD players. Basically they were able to upsample 44.1K to 384k, bypass the DAC's digital filter and play this through AD1955 and Wolfson parts.

Here's the screen. I also can confirm the same behavior with the JRiver Media Center. Oh and I have no DSP that can affect the sample rate of the file.
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File Type: jpg screen.jpg (326.1 KB, 332 views)

Last edited by SunRa; 10th April 2011 at 05:34 PM.
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Old 10th April 2011, 06:20 PM   #305
exa065 is offline exa065  Canada
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Quote:
Originally Posted by SunRa View Post
The funny thing is that when building this DAC I researched the white papers released by Anagram regarding their technology used in Cambridge CD players. Basically they were able to upsample 44.1K to 384k, bypass the DAC's digital filter and play this through AD1955 and Wolfson parts.

Here's the screen. I also can confirm the same behavior with the JRiver Media Center. Oh and I have no DSP that can affect the sample rate of the file.
Your setup from the screen shot is correct and identical to mine. When I play Carmen in the original WAV format I also have the (floating point) notice the way you do. This is the source format. Normally I listen tho this piece converted to WavPack, which is Integer. That's why I never noticed the message.

I trust Foobar, J. River and exaU2I, so congratulations! You made history! You are playing 352.8 kHz.
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Last edited by exa065; 10th April 2011 at 06:35 PM.
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Old 10th April 2011, 06:25 PM   #306
exa065 is offline exa065  Canada
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SunRa,

I've noticed on your screen shot that in the Foobar toolbar you have a little visualization effect - Spectrum. It consumes lots of CPU resources at 352.8 kHz. Depend on the CPU you are using it may be beneficial to have it disabled.

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Old 10th April 2011, 06:42 PM   #307
SunRa is offline SunRa  Romania
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Hi exa,

Well, the LED indicators seem to tell that's 352.8K I am playing alright. I'll take a closer look tomorrow on this. It would be great checking this with an oscilloscope, maybe I can find something within the DIY community here in Bucharest.

The 24 bits files causing the noise are from HERE the bottom half of the page. When playing these through cPlay (downsampled to 192) they are OK.

Can't tell why the 32 bit files are crystal clear and all of the 24 bit files are making that hiss in the background.

Anyway, this thing is getting really exciting...
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Old 11th April 2011, 07:51 AM   #308
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Quote:
Originally Posted by AR2 View Post
I just checked their website, and yes there is a crossover there plus support for Audio Units. I am sure there is a room correction plug in somewhere... haha this is awesome, thank you Ray!
Last question, when you play FLAC files, do you need to convert them or you play them as is?
You just "drop" Flac files in the Pure Music "Flac player" window..
There are several optional configurations setting and you choose what suits you.
With the default setup Pure Music adds a dummy album/melody in iTunes / iTunes database with tagging from the FLAC file.
These "dummies" are just for integration of the FLAC files in iTunes database as the FLAC, AIFF, WAV, DXD, etc. are played directly by Pure Music.
I use full memory play and with DXD and AIFF/WAV files that are upsampled (on disk) to 352.8k/32bit you need either a fast local disk or a 1Gbit network with a fast file server and it still takes 5 to 10 second to load the 500MB to over 1GB files.
I will experiment with hybrid play where the file starts playing before the whole file are loaded into memory.
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Old 11th April 2011, 08:50 AM   #309
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Quote:
Originally Posted by RayCtech View Post
I use full memory play and with DXD and AIFF/WAV files that are upsampled (on disk) to 352.8k/32bit you need either a fast local disk or a 1Gbit network with a fast file server and it still takes 5 to 10 second to load the 500MB to over 1GB files.
I will experiment with hybrid play where the file starts playing before the whole file are loaded into memory.
If the exa unit would show any differences in case those "audiophile" players
are used, we'd know that the device fails to decouple properly from the PC.

However. No worries.

Quote from homepage EXADEVICES:
Quote:
"Galvanic isolation of the I2S output from the FPGA core and the USB ground virtually eliminates jitter and common noise originated by the PC."
I'm sure they verified what they're claiming. I mean... ...they call their unit an ultra-high-end device.
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Old 11th April 2011, 08:51 AM   #310
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Quote:
Originally Posted by SunRa View Post
Hi exa,

Well, the LED indicators seem to tell that's 352.8K I am playing alright. I'll take a closer look tomorrow on this. It would be great checking this with an oscilloscope, maybe I can find something within the DIY community here in Bucharest.

The 24 bits files causing the noise are from HERE the bottom half of the page. When playing these through cPlay (downsampled to 192) they are OK.

Can't tell why the 32 bit files are crystal clear and all of the 24 bit files are making that hiss in the background.

Anyway, this thing is getting really exciting...
Hi SunRa,

I checked my DXD 352.8k/24bit files (23 albums) and all are PCM integer and plays without any kind of noises.
If you have a pointer to where the 32 bit files can be downloaded I would like to test those also.

I will also convert some DXD files to floating point format and check what happens then...

Have you checked the input data format your DAC chip defaults to?
You should be able to change between several formats...
As your DAC only uses 24 bit of the 32 bits that are clocked in each word clock frame it is possible that there are some misalignment like left vs. right justified etc..??
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