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dudefellaguy

Member

Registered: 2012-02-08

Posts: 21

Lexicon Lambda duplex support

I have a Lexicon Lambda USB audio interface. It works fine other than the fact that I can't get it to run in duplex mode. Right now when I record I use the Lambda for getting input from microphones and I use my onboard soundcard to output sound to my monitors. This is not desirable because I can't hear what I'm recording and what I'm recording along to at the same time.

I found this: http://www.spinics.net/linux/fedora/als … 01899.html which seems to identify the problem pretty well (assuming that he knows what he is talking about). No solution is offered and I am having serious trouble trying to find one myself. My only thought right now is to patch the module responsible for throwing the error so that it handles the way the interfaces are numbered when this particular device is connected to. The only problem is that I have no idea where to start. Do I have to recompile the whole kernel? The snd_usb_audio module? The usb module?

What I am asking for is some pointers on where I might start looking for the source code files so that I can attempt to remedy this problem, although any help will be much appreciated.

Trilby

Inspector Parrot

Registered: 2011-11-29

Posts: 30,512

Website

Re: Lexicon Lambda duplex support

I'd be surprised if you need to fiddle with source code.  Do you have an ~/.asoundrc ?  Have you tried configuring via that file (read the alsa wiki page for info) ?

EDIT: I have a Lexicon Omega in mothballs (figuratively) I'll hook up over the weekend to see if I have any luck.  If I get it working I'll report back on what alsa configs worked.

Last edited by Trilby (2012-05-25 00:10:16)

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"UNIX is simple and coherent" - Dennis Ritchie; "GNU's Not Unix" - Richard Stallman

dudefellaguy

Member

Registered: 2012-02-08

Posts: 21

Re: Lexicon Lambda duplex support

I do have an ~/.asoundrc and I have been through that wiki page multiple times before, I couldn't find anything that worked. The error messages I'm getting (from dmesg) seem to be from a lower level than the one which ~/.asoundrc works at. That being said, there are downstream solutions to upstream problems.

According to a follow up post:

They may have used the same code from their Omega, which I believe might have 8 interfaces, and just changed the number of interfaces without actually renumbering them.

So, the Omega might not even be susceptible to this issue.

Also, in the linux source code, I found out that linux-3.3/drivers/usb/core/config.c prints the error messages that were in the aformentioned post (and that I see too). I have not yet read enough of the code/docs to have the vaugest idea of how a solution might be implemented.