USB Audio 2.0 problems

Sub forums for various specialist XMOS applications. e.g. USB audio, motor control and robotics.
muntablues
Active Member
Posts: 34
Joined: Tue Dec 20, 2011 2:45 pm

USB Audio 2.0 problems

Postby muntablues » Tue Dec 20, 2011 4:03 pm

Hi all

I have bought USB Audio 2.0 Ref. Design and after first tests I have some problems.

I don’t know if there is something wrong with my HW so I just ask for some experience from other users.

I use standard firmware from XMOS and I didn’t change anything. But now to the problems:

1. If I start to play some audio I have a long delay till I hear the sound. It can last up to 1 second till I hear the sound. I have tried an other DAC (PCM5102 in parallel on the same I2S interface) and there is no delay!

2. If the sound is playing, I can hear some distortion (little clicks every 2-3 seconds). I don’t know where these clicks come from. Maybe there is a driver problem, but I haven’t found anything about that topic in the forum…

It would be great if someone could share his experience!

Thanks for any info!

MB
Ali
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Posts: 22
Joined: Mon Jun 07, 2010 12:50 pm

Postby Ali » Tue Dec 20, 2011 9:12 pm

Hi MB,

What saple rate, system, OS and driver version are you running on, and what version of the XMOS USB audio code are you using?


Thanks
Ali
muntablues
Active Member
Posts: 34
Joined: Tue Dec 20, 2011 2:45 pm

Postby muntablues » Tue Dec 20, 2011 9:58 pm

Hi Ali

OS: Win7 x64 PRO
Sample Rate: 44100 ... max

Driver and FW: latest

I testet again and I think it is a WIN7 problem. If I have high CPU load there are no ticks, else i can hear them.

I forgot to say, that my internal audio card (notebook) has similar audio problems. My external USB card does not have any problems. But before I have installed Win7 there was no audio problem with ther internal card.

I will test on a XP PC maybe I have better results.

I could make some short recording from a simple sine wave, where you can here what I am talking about. Just let me know!

Thanks

MB
muntablues
Active Member
Posts: 34
Joined: Tue Dec 20, 2011 2:45 pm

Postby muntablues » Wed Dec 21, 2011 12:05 am

I tested again and the problem is my RealTek audio driver. If I remove that driver, there are no clicks anymore. So I think point 2 is solved.

Point 1 is still open, but i will use the PCM in my design, so I think I can live with that *gg*

Thanks
MB
Ali
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Posts: 22
Joined: Mon Jun 07, 2010 12:50 pm

Postby Ali » Wed Dec 21, 2011 11:11 am

Hi MB,

Pleased to hear you found the cause of the problem.

For point 1, the delay after pressing play, this is due to the auto mute feature of the codec we use - it takes a little time when the audio starts.

Cheers
Ali
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phalt
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Joined: Thu May 12, 2011 11:14 am

Postby phalt » Wed Dec 21, 2011 12:15 pm

Topic moved to correct forum

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