On Fri, Mar 14, 2014 at 6:41 PM, Fons Adriaensen <fons(a)linuxaudio.org> wrote:
On Fri, Mar 14, 2014 at 05:39:08PM +0530, Rustom Mody
wrote:
Of late I am getting some amount of hiss from my
speakers.
I believe its a software problem because it is absent at startup and
audibly starts sometime during the boot process.
My system is fairly vanilla h/w -- ordinary Intel desktop with builtin
soundcard, ordinary speakers.
The only non-vanilla things maybe some things I installed when playing
around with a TASCAM
How on earth can anybody help you if you give so little information.
Sorry not sure what else I should have given...
lspci ?
aplay -l ??
* Do you have active speakers (built-in amplifier) or is there an
amplifier in between the sound card and the speakser ? If so, which
input are you using ? How are things connected ?
* Using ALSA/Jack/Pulse ??
No jack (to start with at least when the hiss sound starts)
I am using debian -- which meant that there was no pulse until recently
Of late I see occasionally some pulse related messages.
eg I get these messages when I start audacity:
----------------------------------
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side
ALSA lib pulse.c:243:(pulse_connect) PulseAudio: Unable to connect:
Connection refused
ALSA lib pulse.c:243:(pulse_connect) PulseAudio: Unable to connect:
Connection refused
Expression 'stream->playback.pcm' failed in
'src/hostapi/alsa/pa_linux_alsa.c', line: 4611
Expression 'stream->playback.pcm' failed in
'src/hostapi/alsa/pa_linux_alsa.c', line: 4611
Expression 'stream->playback.pcm' failed in
'src/hostapi/alsa/pa_linux_alsa.c', line: 4611
Expression 'stream->playback.pcm' failed in
'src/hostapi/alsa/pa_linux_alsa.c', line: 4611
---------------------------------
* TASCAM is a brand name. They are hundreds if not thousands of
different things with that name on it. So what is 'a TASCAM',
and what did you install for playing around ?
Yeah I know :-)
I guess the TASCAM reference is a red-herring.
I tried it more than 2 years ago.
There was no (hiss) issue then.
Dont have the hardware right now so dont know the number/spec.
The hiss has started after some recent debian upgrade -- couple of weeks
Apart from that, hiss is usually the result of either
- something broken,
- or using the wrong inputs,
- or a volume control set too high.
Another cause could be the mic inputs of your sound card
routed to the outputs. Check the mixer.
Are you asking for hardware or software checking?
Hardware: There is only one connection -- the speaker into the soundcard.
No mic, no line.
Software: I will need to know how to check.
For now, I checked with xfce4-mixer.
If I turn down master or front-mic the hiss reduces
However then musescore (my main use right now) also becomes too soft
Interestingly there was a musescore upgrade just a day or two ago
And now I am seeing segfaults with this message:
$ Alsa_driver: pcm_drop(play): Input/output error
pcmStop failed
Segmentation fault
Dont know that this has anything to do with the original hiss question.
Ciao,
--
FA
Thanks for the tips
Rusi