Disappearing USB Audio Device

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Level 1

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Disappearing USB Audio Device

I'm hoping someone has some ideas to rectify this short of re-installing OSX from scratch.

The problem is that my USB audio device (Lexicon U22) works fine until I try to play a video in Quicktime... then it disappears from system preferences, and of course, I get no audio from the video. When I reboot, it returns and works with iTunes audio, but as soon as I try to play a video, it disappears.

I'm currently trying to isolate if its a particular codec that causes this as I have WMV, MPEG, and MP4 videos. I think it may be related to Perian and/or Flip4Mac. But it might be related to Quicktime in general. No idea.

The problem started when I reinstalled OSX Leopard at Christmas, and then restored my settings and files from a Time Machine backup. I've had nothing but problems with audio since then. First of all, it wouldn't remember my preferred audio device. That was rectified by blowing away the preferences files and repairing permissions.

Now this issue lingers, and I've tried rolling back Perian, Flip4Mac, and reinstalling my Lexicon USB audio drivers, in several different orders/iterations and nothing seems to work.

Any ideas?

2009 Mac Pro, 2010 Mac Mini, iPhone 4, iPad, Mac OS X (10.6.6), 2009 Time Capsule

Posted on Feb 7, 2011 1:43 PM

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Answer 1

Feb 24, 2011 12:37 PM in response to VirtualRain

The only thing I can think of is that your QT movies could be using some weird audio codec/sample rate/bit depth that your USB device doesn't like/ can't handle. Are you testing this with just one QT, or do all of your QT's exhibit the same problem?

Just a few wild ideas... before you launch QT, try quitting iTunes and anything else that uses audio...

Secondly, instead of re-booting, try logging out and back in.... at least that would save you a bit of time...

Past that... dunno...

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Answer 2

ed81

Level 1

0 points

Jul 2, 2011 2:19 AM in response to VirtualRain

Same problem with my iMac and U22 here. My Lexicon interface sometimes disappears too. For instance: a few minutes ago, when I open up Youtube in Safari... no sound while Itunes still playing sound. I stop and start Itunes again and there's no sound anymore from any program. Its completely gone from the iMac audiodevice-list too. The Mac needs a reboot to solve the problem. I don't have Perian and/or Flip4Mac installed.

Is there a application that shows which audio/video codecs are currently running on the system??? I know there is a windows program that monitors all codecs that comes with an codec- pack..

Any advice much appreciated.

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