DSD audio over USB

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Stef
New User
Posts: 3
Joined: Mon Jan 30, 2012 4:54 pm

Re: DSD audio over USB

Postby Stef » Thu Jul 12, 2012 5:02 am

Hi Gabor,

If you can hear the music the only thing that I can think of is that you don't have a proper low pass filter. If there was something wrong with the PC part of the audio chain, then you would have no output (try for example to lower the volume in Foobar).
What kind of CS4398 implementation do you have? What kind of low pass filter and what LP frequency did you select for the direct connection to the amplifier?
Don't worry about the XDE messages, they are normal.
gaboca0527
Member
Posts: 8
Joined: Sat Mar 31, 2012 3:56 pm

Postby gaboca0527 » Thu Jul 12, 2012 11:55 am

Hi Stef,

Thank you for your answer!

If I change the volume in Foobar, the music disappear. It is normal, because the implemented header bytes changing... What do you think about the WASAPI plugin for Foobar? Maybe is it neccessary for playing? I have WinXP on my PC and can not try this plugin, but If you tell me, that it is neccessary I try it on a WIN7 system.

I use the internal 50kHz LP filter in the CS4398 and an analog LP at the output with 50kHz . I do not use additional LP filter for the direct connection to the amplifier. It has an internal LP filter at the beginning with 20kHz border freq.
I think the LP filter can not solve this problem, because the noise is wide spectral, perhaps white noise. I can not measure it, because I do not have spectrum analyzer.

Thanks again,
Gabor
gaboca0527
Member
Posts: 8
Joined: Sat Mar 31, 2012 3:56 pm

Postby gaboca0527 » Mon Jul 23, 2012 2:34 pm

Hi Stef,

I found something.
If I use Win7 operating system and Foobar with WASAPI plugin, the system works good. With winXP it is not works good, the sound is very noisy.

Other thing is with the encapsulate tool. If I run this tool on Win7 x64 system with Java 7 update 5, the result of the converting is not good. If I make it on WinXp and with Java 7, it is ok.

What is your next plan with this XMOS device?
buxy
Newbie
Posts: 1
Joined: Mon Jul 23, 2012 10:30 pm

Postby buxy » Mon Jul 23, 2012 10:45 pm

Hi!

I've found a bug in the encapsulating tool: In the first <4K buffer there are 1 or 3 more bytes in the output (depending on operating system or Java version), sometimes at worst rendering the file completely unusable.
Please change the line in the source code
in.read(bufferTwo, n - dsd_data_pointer + 1, 4 - (n - dsd_data_pointer) % 4);
to
in.read(bufferTwo, n - dsd_data_pointer, 4 - (n - dsd_data_pointer) % 4);

Thanks,
BuXY

p.s. sorry for decompiling your nice code, Stef... :/
altvirus
Junior Member
Posts: 6
Joined: Fri Sep 28, 2012 4:55 am

Postby altvirus » Fri Sep 28, 2012 5:02 am

Hi Stef,

I have USB Audio 2.0 Reference Design and want to upgrade it with

DSD over USB v1.1. but I can't figure out the implementation

altvirus
Junior Member
Posts: 6
Joined: Fri Sep 28, 2012 4:55 am

Postby altvirus » Fri Sep 28, 2012 5:02 am

Hi Stef,

I have USB Audio 2.0 Reference Design and want to upgrade it with

DSD over USB v1.1. but I can't figure out the implementation

gaboca0527
Member
Posts: 8
Joined: Sat Mar 31, 2012 3:56 pm

Postby gaboca0527 » Fri Sep 28, 2012 10:27 am

Hi Altvirus,

What part of the implementation is not clear for you?

At first you have to donload the free XMOS Development tools and the WIN or MAC driver for this KIT.
I recommend to you the Thesycon eval driver. It works for me.
After registration you can download it here:
http://www.xmos.com/products/development-kits/usbaudio2

Next step is donwload Stef's firmware to the hardware.
There is two way for do that.

One way is a little bit longer. You have to load the .xe file into a new project in the Development Tools SW, you have to connect the KIT with the USB interface board, set up every parameter and run the upgrade.
Not difficult, but at first you have to learn how to use the Development Tools SW. Later if you want to make own projects or some modifications, you have to learn it anyway.

Other way is faster. After the Development SW installation, you will find a Command Prompt in the program directory. It is an easy command line tool. You have to connect the KIT with the USB interface board and type the flashing command and the path of the .xe file into the command line and the upgrading process will start.

Of course you can find on the XMOS website the original firmware of this KIT. So you can load back anytime the original firmware.

I hope I could help to you.

Gabor
altvirus
Junior Member
Posts: 6
Joined: Fri Sep 28, 2012 4:55 am

Postby altvirus » Sun Oct 07, 2012 7:35 am

Hi, Gabor
Thank you for your kind reply
with your help, I could make the firmware ready.
but I have a few other questions.
- need a ddc firmware separate from dsd firmware?
- connect ddc firmware with the usb?
- regarding the second way you told me, can you tell me more info about the flashing command & the path or a sample that I can directly apply to.
I really appreciate your help
Altvirus
gaboca0527
Member
Posts: 8
Joined: Sat Mar 31, 2012 3:56 pm

Postby gaboca0527 » Sun Oct 07, 2012 7:28 pm

Hi Altvirus,

You do not need more firmware for the DSD mode. What is this ddc firmware?

Here you can find all manual for this KIT just choose your reference design kit:
http://www.xmos.com/support/kits

And here you can find how to use the command prompt:
https://www.xmos.com/download/public/USB-Audio-2.0-Firmware-Installation%282011-06-14%29.pdf

Gabor
altvirus
Junior Member
Posts: 6
Joined: Fri Sep 28, 2012 4:55 am

Postby altvirus » Mon Oct 15, 2012 1:53 am

HI! Gabor
Regarding xmos command prompt, I ran intto another problem.
In the screen, it says

C:Wxmos>xflash usb_audio.xe
Cannot connect, device is in use by anoteher process
xrun: Problem in connection to device

What shoud I do then?
sorry for bothering you too much
Altvirus

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