[LAU] Edirol FA-101 and output level

Daniel Wagner wagi at monom.org
Thu Aug 23 02:50:35 EDT 2007


Hector Centeno wrote:
> Thanks Daniel,
> 
> I checked out again from SVN and rebuilt. Now I have the test-volume program
> but this is what I get when I try to run it:
> 
> $ ./test-volume 0 5 -32768
> /home/hector/Desktop/libfreebob/tests/.libs/lt-test-volume: symbol lookup
> error: /home/hector/Desktop/libfreebob/tests/.libs/lt-test-volume: undefined
> symbol:
> _ZN16FunctionBlockCmdC1EP15Ieee1394ServiceNS_18EFunctionBlockTypeEhNS_17EControlAttributeE

ldd loads the wrong library for the test-volume program. It loads the 
current installed libfreebob library (e.g. installed in /usr/lib or 
/usr/local/lib). Try to set the LD_LIBRARY_PATH environment variable.

e.g for bash:

$ export LD_LIBRARY_PATH=/home/hector/Desktop/libfreebob/src/.libs
$ ./test-volume 0 5 -1000

Then ldd should find the correct library. If that works you could 
overwrite the installed libfreebob version with your own compiled 
version. But if you are not completely sure what you are doing I do not 
recommend this step. It could break you installation.

> Also I noticed that on that old thread where this test utility is discussed
> ( http://linuxaudio.org/pipermail/linux-audio-user/2006-November/039911.html)
> there is mention of not being able to set the outputs with it. Is this
> still true?

Yes this mails is still true. Though to be honest I have never tried it 
really. I've just implemented the program and looked at the responses 
from the devices. I think I should really test tonight.

> What I need is to lower the volume of the outputs.

I now that the FA-101 has a high output level at default. Even the 
output level for the headphones are really high.

> Also in that thread there is mention of a "mixer" for doing that. 

IRC, the FA-101 is the only device in the BeBoB family which has a very 
simple mixer implemented. I can't really tell what you can do with it. 
There is a schematics drawn on the device top. Maybe that gives you a 
clue what the built in mixer can do.

> Would that be a software mixer part of the FA-101 drivers present in Windows? I can't see
> any reference to a software mixer in the FA-101 manual.

Sorry, I don't know.

> My problem is that when I plug my ADAM-A7 monitors using balanced cables the
> output is too hot and even causes some distortion, when using unbalanced
> cables the situation is better but still it feels too hot. The odd thing is
> that through the headphones the FA-101 level sounds normal and there is no
> distortion. I tested the same monitors with an M-Audio Audiophile and the
> level sounds normal. The A7s have volume control labeled from -60db to 6db
> with 0db at twelve o'clock. Using the FA-101 I can't go pass -30db (using
> balanced or unbalanced cables). With the audiophile I can go up to 0db and
> sounds fine.

As I said previously that FA-101 has really high output levels. 
Hopefully you can set the output level with the test program. Of course 
the test program should be improved :)

> I'll appreciate any help on this since I'm in the middle of several
> projects.

No problem.

cheers,
daniel



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