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I hate Alsa



Debian Testing up to date as of yesterday.
Kernel 2.6.22
Sound from on-board Intel (snd_hda_intel)
Kmix as the mixer

When I used OSS I had no audio problems at all - everything (playback 
and recording) just worked but since I went over to Alsa (about a year 
ago) I've had trouble getting recording to work.

Normally I find that playback gives no problems and I did for a short 
period get playback and recording working properly then after a Debian 
upgrade the recording stopped working properly again.

If I try to record (arecord) using a microphone I cannot move the 
recording volume slider above 70% otherwise I start getting extremely 
distorted sound on playback (aplay) and although the recording volume 
is adequate there is a loud background hum. If I reduce the recording 
volume to about 60% the loud hum changes to a noticeable hiss but the 
recorded voice is too low.

I have to use the 'Digital' slider on the Kmix input tab to control 
microphone volume - none of the other sliders seem to do anything. I 
also have to have the first capture slider on (un-muted) to get any 
sound at all but it makes no difference whether that slider is at the 
bottom or not - it does not affect the volume.

I also have a record deck with a USB connection which I last used under 
OSS. The setup was working then and, as I remember, it was pretty 
straightforward to set up. Since that time there have been many 
Debian updates and I'm almost certainly using a later kernel and I'm 
now using Alsa.

When I came to use it this time in conjunction with Audacity, which I 
was using last time, I can't get a peep out of it.

I have tried various inputs without success. The appropriate modules 
are loaded including snd_usb_audio.

When the USB lead is plugged in I get this in the logs:

kernel: usb 1-7.1: new full speed USB device using ehci_hcd and address 
6
kernel: usb 1-7.1: configuration #1 chosen from 1 choice
kernel: input: Burr-Brown from TI     
USB Audio CODEC  as /class/input/input4
kernel: input: USB HID v1.00 Device [Burr-Brown from TI               
USB Audio CODEC ] on usb-0000:00:1d.7-7.1
kernel: usbcore: registered new interface driver snd-usb-audio

a little further on in the log I see:

kernel: cannot submit datapipe for urb 0, error -28: not enough 
bandwidth

Originally I got this in the log:

kernel: cannot submit datapipe for urb 0, error -38: enable 
CONFIG_USB_EHCI_SPLIT_ISO to play through a hub

so I enabled that in the kernel and recompiled although I'm not using a 
USB hub and then got the 'not enough bandwidth' error.

As you may have gathered I'm beginning to take a dislike to Alsa.

Can anyone suggest some fault tracing procedures please?

-- 
Barry Samuels
http://www.beenthere-donethat.org.uk
The Unofficial Guide to Great Britain



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