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AK4490 USB Dac with dsd support.

Coming update of firmware and New DAC mainboard with SPDIF

For this weekend we have two project:

Firmware update:

The attached firmware have most of the noise during sample rate switch removed. I have tested with DoP and PCM which works very well. There is still an issue with Native DSD. But by using DoP it is still pure DSD it is only packed in an container.

New firmware for the frontpanel for changing filter settings in the DAC

New DAC Mainboard with SPDIF support:
We will on monday order Mainboards with SPDIF 1 RCA and 1 Optical and a I2S port. It is based around TI SRC4392 as we can make the SRC4392 slave of the masterclock.

BR

Sonny
 

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Hi Sonny,

finally I can the package today. I just completed to assemble the boards with the SMPS.

I can't get the display light up. If I understand correctly the schematic the J6 is not required when the flat cable is connected to the dac.

Any advise? Attached are the pictures of the arrangement that is as per the picture that you post some time ago using the cables that was in the box...

Thanks for your help and Regards,
Enrico
 

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For this weekend we have two project:

Firmware update:

The attached firmware have most of the noise during sample rate switch removed. I have tested with DoP and PCM which works very well. There is still an issue with Native DSD. But by using DoP it is still pure DSD it is only packed in an container.

New firmware for the frontpanel for changing filter settings in the DAC

New DAC Mainboard with SPDIF support:
We will on monday order Mainboards with SPDIF 1 RCA and 1 Optical and a I2S port. It is based around TI SRC4392 as we can make the SRC4392 slave of the masterclock.

BR

Sonny


The Native DSD pop at track startup is only an issue for Linux users. As Linux is required for Native DSD for this DAC. However Linux and Native DSD is also required for DSD 256 operation without the Windows Theyscon driver.

I'll also add that although DoP is lossless, there is an audible difference between DoP and native. I'm guessing this is due to the additional steps of processing of packing/unpacking the DSD data from the PCM container. However it is a small difference.

Does this new mainboard have the same popping issues with native DSD Sonny?
 
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It Can be but volumio that is Linux based as well does not suffer those pops.!



Sent from my iPhone using Tapatalk


It's only with Native DSD and only when new albums are started. If you have it on random play, the pop happens at the start of each track. And this is without changing sample rate. I have HQ player set to upsample everything to DSD 256.

Since this technique gets the best sound from all formats out of this DAC (PCM and DSD) smooth pop free operation would be nice.
 
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Yes i know Mike
But This is not the case with volumio.


Sent from my iPhone using Tapatalk


I'm not sure why then. Audiolinux/HQplayer sounds superb. I'm running in command line mode for the least amount of processing possible. My NAA is operating like a "black box" device. Turn on and 10 seconds later it's ready to go. Push power button, and off within 3 seconds.

But same issue occurs running HQplayer direct on Audiolinux. So it's nothing to do with the configuration. Somehow the timing of muting the outputs must be off compared with when used with Volumio.

Probably the only way to find a solution would be to replicate my setup. Audiolinux comes with a 30 day free trial of HQplayer if you don't own a copy.

Everything is pre-installed. Just burn image to stick with Rufus on Windows, and boot from stick. Couldn't be easier.
 
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There is Many questions here. But basicly i do not see it as my problem as the latest firmware Runs with Mac os/x Windows and volumio without pops.

The questions that rises is the following :
1) what if you choose another player than hq player and plays an dsd256 directly? When I play using volumio it is an real dsd file. It is not converted using hq player to dsd. If I use hq player on Mac OS/x on a Mac mini the player start to have gaps when playing dsd128 when moving the cursor across the screen. With other players this is not a problem. I do not see this player has a finished product... Sorry!
2) Do we know if hq player has the right leader/trail on the signal.
3) ifi has an faq about pops/clicks when playing dsd files. So my Dac is not the only one having trouble . The latest firmware switch between pcm, dop and dsd on the platforms mentioned in the start of this answer with very low levels of click . Only when turned to 0dB on my preamp I can hear an click at an very very very low volume.

So if you want to test different platform I would like to hear about it but mail me instead of using this thread or the direct dsd drive thread.
All this player test belongs to an separate thread.
I hope you understand..

BR

Sonny


Sent from my iPhone using Tapatalk
 
There is Many questions here. But basicly i do not see it as my problem as the latest firmware Runs with Mac os/x Windows and volumio without pops.

The questions that rises is the following :
1) what if you choose another player than hq player and plays an dsd256 directly? When I play using volumio it is an real dsd file. It is not converted using hq player to dsd. If I use hq player on Mac OS/x on a Mac mini the player start to have gaps when playing dsd128 when moving the cursor across the screen. With other players this is not a problem. I do not see this player has a finished product... Sorry!
2) Do we know if hq player has the right leader/trail on the signal.
3) ifi has an faq about pops/clicks when playing dsd files. So my Dac is not the only one having trouble . The latest firmware switch between pcm, dop and dsd on the platforms mentioned in the start of this answer with very low levels of click . Only when turned to 0dB on my preamp I can hear an click at an very very very low volume.

So if you want to test different platform I would like to hear about it but mail me instead of using this thread or the direct dsd drive thread.
All this player test belongs to an separate thread.
I hope you understand..

BR

Sonny


Sent from my iPhone using Tapatalk


Since there's not very many albums available in DSD 256 yet, resampling must be preformed to enjoy the superior sound quality of DSD 256. It's also required to avoid passing the PCM through the AK4490's SDM/SRC section.

Jriver does a poor job of this. DSD 256 is impossible on Windows or OSX with your DAC at this time, so Linux must be used. There's no other Linux based media players that can come close in sound resampling PCM to DSD 256. With Volumio you can't upsample PCM to DSD 256 using the superior algorithms that HQplayer uses. Nor are they working together with Roon to have the best mobile GUI on the planet, combined with the very best SDM/SRC algorithms.

For my application HQplayer must be used also because I'm using the NAA system so the server can be located in a remote location.
 
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Also I forgot to mention that HQplayer requires lots of CPU power once you get to resampling PCM to DSD 128 or higher. This is probably why you were having trouble. It's recommended to use a PC with a modern I7 quad core processor. Any less and you start to have trouble with DSD 128 and higher. The idea is to use a powerful server located in an office or somewhere, and install the NAA Daemon on a very low powered computer that is connected to the DAC. This way the noisy high powered computer is not connected to the DAC. Also the NAA computer uses a large FIFO buffer and plays from RAM only for better sound quality.

So there is nothing wrong with the software. It's already been through 6 years of refinement. The problem for you is most likely the Macmini you are running it on is under powered. I have an i5 Macmini and same problem with DSD 128 and higher. Try with a new Intel 4th gen+ i7 quad core processor PC instead. I tried with this cheap 500 Euro computer, and it ran no problem. 30% CPU load with DSD 256 resampling from redbook:

http://www.bestbuy.ca/en-CA/product...spx?path=af0a973eb4f1021fe8e7a751feee0612en02
 
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