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