[linux-audio-user] alsamixer and the audiophile 2496
Eric Dantan Rzewnicki
eric at zhevny.com
Fri May 14 23:44:50 EDT 2004
luis jure wrote:
> el Thu, 13 May 2004 15:53:25 -0400
> Eric Dantan Rzewnicki <rzewnickie at rfa.org> escribió:
>>You should use
>>envy24control instead of alsamixer. Things will make much more sense.
> i'm the OP and yes, i _do_ have envy24control installed. it may make a bit
> more sense, but i can't see that it makes _much_ more sense. i mean, i still
> find many things rather unclear.
> in any case, i'm still puzzled by my original questions:
Ok, first let's make sure we're both looking at the same (or at least
similar) picture. In envy24control I have 5 tabs:
"Monitor Mixer","Patchbay/Router","Hardware Settings","Analog Volume"
and "About". "About" isn't very interesting. "Hardware Settings" I never
need to mess with, so I don't have much to say. I think it mainly
applies if you're connecting some external digital device via S/PDIF. I
don't have any other digital gear so I don't need to mess with this part.
The thing that most confused me at first was that the Mute buttons and
volume sliders on the "Monitor Mixer" page only affect the actual audio
output if "Patchbay/Router" strips are set to "Digital Mix" even though
the level meters continue to function. The sliders and mute buttons are
for controlling levels in the mixer on the card.
If the "Patchbay/Router" strips are set to "PCM Out" or "H/W in" you are
bypassing the card's mixer. PCM Out's are channels for your audio
applications to connect to. They are "Out" from the perspective of the
app. H/W in's are just that, inputs from the audio card hardware.
Selecting these in the "Patchbay/Router" gives you direct monitoring of
the signal going into your hardware. As with the PCM's selecting them in
the "Patchbay/Router" bypasses the card's mixer.
> 1) is it necessary to change mixer settings to toggle between monitoring the
> input and playback?
It depends. You can directly monitor the hardware inputs as described
above by selecting them in the Patch Bay. In this case you have no
software control over levels. For instance, I have my guitar plugged
into H/W In 1. With the "Patch Bay/Router" strips "H/W Out 1 (L)" and
"H/W Out 2 (R)" both set to "H/W in 1" I hear the guitar coming out the
speakers and see the level meters respond in "Monitor Mixer". However,
the sliders and Mute buttons do not affect what I hear even though they
do affect the "Digital Mixer" as displayed in the level meters on the
far left. I can't hear the changes because the mixer is bypassed.
If I set the "Patch Bay/Router" strips "H/W Out 1 (L)" and "H/W Out 2
(R)" both to "Digital Mix" I can still hear the guitar, but now the
controls in "Monitor Mixer" for "H/W in 1" do control the level I hear.
Now, to answer your question, if you leave things like this (patchbay
set to Digital Mix) you shouldn't have to change the patch bay to switch
between monitoring input and playback. You may need to adjust the
sliders in "Monitor Mixer" because now your audio will be coming from
your app on the PCM Out's through the mixer on the card.
If you want to bypass the mixer to monitor the inputs directly, or
monitor playback directly from the PCM's then you need to change your
routing in the patchbay.
> 2) how do you control input level for analog inputs?
In the "Analog Volume" tab the "ADC x" sliders control your anolog to
digital converter levels. likewise the "DAC x" sliders control your
digital to analog converter levels. I always leave my DAC an ADC sliders
for channels 0 and 1 all the way up. (not sure if that's correct
audio-engineering-wise, but it works for me.) If you need more gain at
this stage the "IPGA x" sliders will give it to you. My guess is that it
would be better to get a hotter signal in rather than use these, though.
> 3) is there a way to capture what's being sent to analog outputs?
I think the card's mixer outs go straight to the DACs. As far as my
understanding goes, the mixer doesn't present any outputs to
applications ... I think what you want has to be done at the application
level. For me, that means using jack. Maybe there's some sort of
.asoundrc magic that could make it happen for you. I have yet to grok
anything more than minimal usage of that though.
Heh. :) I feel like I maybe should have just written a tutorial. Anyway,
I hope this helps. I need to get to bed now. Good luck.
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