[Voyage-linux] snd-usb-audio

[Joshua Anhalt]

Without much familiarity with these speakers, I suspect the Alix board  
may not be able to provide sufficient power to your speakers.  (Am I  
understanding you and the Logitech website correctly, all power for  
the speakers originates from the single USB port?)

If you have a powered USB hub (a hub with an attached power supply),  
try connecting the speakers through the hub to the Alix board.

If you have other USB peripherals on this system, try removing them to  
reduce the power draw.

The Alix 2d2 (the successor to your Alix 2c2) increases the available  
current to the USB ports.  If using the hub works, but you require a  
more compact solution, this newer board may be able to directly power  
the speakers.

Standard USB 2.0 ports are speced to source at most 500mA at 5V (or  
2.5 Watts.)  Many computers can source more than this, but it is not  
guaranteed.  There are also powered USB ports, but these are less  
common and not specifically related to this question.

Joshua

On Nov 23, 2009, at 10:56 AM, Johann Wolfgang Goethe wrote:

> Hello Voyage community,
>
> I'm running voyage-linux on my Alix 2C2 as a music server with MPD
> (Music Player Daemon). As loudspeakers I use Logitechs Z-5, which are
> Loudspeakers that have a DAC inside and are driven via USB (without
> external power supply).
> These loudspeakers, when plugged in load the kernel-module
> snd-usb-audio. So far everything works really great. But from time to
> time (about two or three minutes, sometimes half an hour) the kernel
> disconnects this device and reconnects it again.
> Here is an output of dmesg:
>
> [25388.082748] generic-usb 0003:046D:0A13.004E: input: USB HID v1.00
> Device [Logitech Logitech Z-5 Speakers] on usb-0000:00:0f.4-1/input2
> [25436.251122] hub 2-0:1.0: port 1 disabled by hub (EMI?), re- 
> enabling...
> [25436.252040] usb 2-1: USB disconnect, address 79
> [25436.467851] usb 2-1: new full speed USB device using ohci_hcd and  
> address 80
> [25436.605078] usb 2-1: configuration #1 chosen from 1 choice
> [25436.676864] input: Logitech Logitech Z-5 Speakers as /class/input/ 
> input79
> [25436.677838] generic-usb 0003:046D:0A13.004F: input: USB HID v1.00
> Device [Logitech Logitech Z-5 Speakers] on usb-0000:00:0f.4-1/input2
> [25498.971441] hub 2-0:1.0: port 1 disabled by hub (EMI?), re- 
> enabling...
> [25498.972359] usb 2-1: USB disconnect, address 80
> [25499.188171] usb 2-1: new full speed USB device using ohci_hcd and  
> address 81
> [25499.325339] usb 2-1: configuration #1 chosen from 1 choice
> [25499.397019] input: Logitech Logitech Z-5 Speakers as /class/input/ 
> input80
> [25499.397180] generic-usb 0003:046D:0A13.0050: input: USB HID v1.00
> Device [Logitech Logitech Z-5 Speakers] on usb-0000:00:0f.4-1/input2
>
> Unfortunately I can not find a solution for it and I would like to ask
> for your experiences in this case.
>
> Thank you very much for your help in advance.
>
> _______________________________________________
> Voyage-linux mailing list
> Voyage-linux at list.voyage.hk
> http://list.voyage.hk/mailman/listinfo/voyage-linux
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://list.voyage.hk/pipermail/voyage-linux/attachments/20091124/8d4d0769/attachment-0001.html>