[linux-audio-user] USB Audio has played but no longer does so.

Mark Knecht mknecht at controlnet.com
Sun Sep 19 18:04:25 EDT 2004


Chris,
    Sorry that you haven't gotten many answers to this question. Let me 
take a shot at it. I'm not promising much.

1) If you get an endless list of devices showing up in 
/proc/asound/cards then clearly something is very, very wrong. I think 
that it's hardly worth proceeding further until this gets sorted out, 
but unfortunately I've never used a USB audio device so I Cannot help there.

2) Try alsaplayer. I'm not clear if this machine is a desktop or a 
laptop. If it was an old style desktop and you were trying to play an 
audio CD then you would normally do this through an audio cable hooked 
to the sound card. However, since your sound card (working or not) is a 
USB device you obviously cannot do this. To get around this issue you 
need to use a CD player that will play the audio digitally across the 
PCI bus. IIRC xmms will not do this, or at least not without special 
plugins. alsaplayer will. Since your sound card (working or not) is at 
the end of a USB cable you need to make sure you are using a player that 
can communicate. Try alsaplayer.

3) alsamixer doesn't work with all sound cards/devices, and I'm not sure 
it works with this one. amixer may or may not, I'm not sure. You could 
be having trouble simply because the sound card is muted and will stay 
that way until you find the right mixer. As you said this originally I 
see you understand the problem. We need someone with more USB experience 
to pony up the appropriate info.

    Again, I wish I could offer more help. I think it's disappointing 
that you've written 3 messages and received no public responses. I hope 
you got more help privately.

With best regards,
Mark

Chris Lyon wrote:
> I'm sorry that I've obviously phrased this question all wrong.
> so I'll try to be a little bit more detailed this time.
> 
> I have now installed Mandrake 10.1 on the machine.
> and now aplay -l does indeed report the existance of UA-100 card
> kscd shows all the typical signs of  playing a cd, it lists tracks, it 
> starts counting when play is pressed,
> But no sound emerges.
> amixer reports no mixer elements, or nothing.
> 
> /proc/asound/cards displays an endless stream of
> 0 [UA100       ]: USB-Audio - UA - 100
>                          Roland UA - 100 at usb-0000:00:07.2 - 2, full 
> speed
> 
> if I try to select a Device with
> aplay -D= *****
> nothing I type in seems to make any sense to it.
> if I try to list pcm devices to plug into the above line with aplay -D 
> the results are to say the least incomprehensable.
> 
> Where do I go next?  This used to work when I installed 9.2 originally 
> but I have been poking & proding for 4 days now and It still desn't 
> work. ONce again I apologies for the way I present my questions but I am 
> NOT pestering before trying, I am on a last ditch attempt to play a CD 
> on a linux box.
> I won't bore you with my background, but I have a little involvement in 
> the synth, computing and audio field and yet this is now getting way 
> beyond a joke.  I have had this playing with Micheal Minns MMUSAUDIO . 
> However ALSA seems the way to go for all things Audio and Linux.
> So how do you check the signal path in a system? and what do you do if a 
> device appears not to be supported by the mixing facilities?
> 
> Chris Lyon
> 
> Chris Lyon wrote:
> 
>> /proc/asound/cards reports
>>
>> 0 [rev20                    ]:VIA686A -VIA 82C686A/B rev20
>>                                      VIA 82C686A/B rev20 at 0xac00, 
>> irq 11
>> 1 [UA100                 ]: USB-Audio - UA-100
>>                                       Roland UA-100 at usb-00:07.2-2
>>
>> So it looks like something is seen but how do I get aplay to play to the
>> UA-100?  The VIA card has alway's reported itself but neither windows,
>> linux or anything else has ever got any life out of it!
>>
>> so do I use the aplay to select the card even thou, aplay -l doesn't
>> list it?
>>
>> Chris
>>
>>
>>
>> Chris Lyon wrote:
>>
>>> Dear all,
>>>
>>> Roland UA-100 plugged into PC, usbview detects interface.
>>>
>>> aplay -l doesn't report any knowledge of the device.
>>>
>>> I believe I have loaded the appropriate modules, snd-usb-audio but 
>>> the system resolutely refuses to make music as it has before. I would 
>>> include the appropriate modules.conf files to show but this E-mailing 
>>> machine and the linux box are not connected and I feel cross reading 
>>> would be a little error strewn.
>>>
>>> Can anyone outline a procedure for checking at which point a problem 
>>> might occur and, if possible, a list of command line utilities that 
>>> can reveal precisely what components are loaded. Is it possible to 
>>> load modules incompletly such that a component identifies it's 
>>> presence but isn't actual functioning. If this is so how does one 
>>> check the dependancies?
>>>
>>> I understand that amix and alsamixer won't recognise the presence of 
>>> a USB connected audio interface, is this the case?
>>>
>>> Any help appreciated.
>>>
>>> Chris Lyon
>>>
>>>
>>>
>>
>>
>>
>>
> 
> 




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