[LAU] Cracking sound via USB (ALSA urb.c:480: frame 5 active: -18)

[Jeremy Jongepier]

On 05/25/2011 11:19 AM, Aurélien Leblond wrote:
>> http://lists.linuxaudio.org/pipermail/linux-audio-user/2010-June/070353.html
>>
>> So not mixing USB1 and USB2 devices but mixing a device performing
>> Full-Speed isochronous-out transactions with a device performing
>> asynchronous transactions. I've tested my Edirol UA-25 with this chipset
>> too and no matter what I tried, full duplex wouldn't work. Does your
>> machine have a Rate Matching Hub? If so could this be the device that
>> does asynchronous transactions maybe? Just guessing here. Or is USB2
>> isochronous and USB1 asynchronous?
> 
> I read this bug description by Intel, and the sentence that decided me
> to buy a USB2 soundcard is this:
> "High-Speed and Low-Speed USB devices are not impacted by this issue."
> 

Low-Speed = USB 1.0
Full-Speed = USB 1.1
High-Speed = USB 2.0
SuperSpeed = USB 3.0

I think this sentence refers to any device other than an audio device.

> I actually have an Edirol UA-25Ex that plainly doeson't work on these
> USB ports, so I went for the M-Audio USB2 High-Speed hoping that would
> solve the problem!
> 

Apparently it doesn't :( Worst case scenario would be that you'd have to
get yourself a USB 2.0 PCIe Express Card to get it to work. Or go
FireWire, but then you'll need an Express Card also.

Best,

Jeremy