"Stuttering" Glitch

[haelen]

Hi I'm running Mountain Lion. I suspect that this is *not* a fault with Audacity but thought I'd run it by....

Occasionally I have a glitch on recordings that sound like a stuttering repetition of a segment of recorded audio. This has actually been recorded as such and is not just on playback.

I am using either a focusrite saffire audio interface with phantom power for this or a usb / xlr converter which also provide phantom power.

Many Thanks,
Tim

[kozikowski]

Did you get to Mt Lion by continuously upgrading one computer, or is this a new machine? Is the USB audio system a home run, or are you going through a USB hub? How full is the machine? Are you doing many different tasks a the same time as the capture? How many things have positive markers under them on the task bar.

Post one of the glitches so we can hear it.

http://forum.audacityteam.org/viewtopic ... 49&t=64936

What's the average repetition rate? About once a week, once every couple of minutes?

Koz

[haelen]

Thanks for the promt reply. This is a new MacBook and I upgraded ro Mt Lion not long after buying it. There's no SB hub involved just the audio interface or XLR / USB converter / preamp.

There are +- 6 apps with markets beneath them when recording. The average repetition rate is about once or twice a week.

Please find attached an example.

Best,
Tim

[kozikowski]

I can't explain that one. In each case the first instance of the word has a trailing segment where the digital process goes insane -- then it repeats the word -- correctly. Since I got nothin', I would do a simple drive test.

Go > Utilities > Disk Utilities > select your system drive and > Verify Disk.

It might also be worth doing a memory test. This is a little rough on a Mac, but it can be done.

http://www.command-tab.com/2008/01/11/h ... -mac-os-x/

Audacity uses memory a little oddly compared do some other programs, so if you have bad or ratty memory way up in high memory somewhere, Audacity may not need it except under some digitally stressful circumstances and then create damage in the sound. But only every so often.

I think there are ways to read the logs and see if they turn up anything. I'm a little fuzzier on that.

Koz

[haelen]

Hi The HD needed a minor repair. The RAM tested fine.

I guess I could close some non-essential apps before recording.

Best,
Tim

[kozikowski]

Live recording is stressful for the machine. That and video production are responsible for trashing more computers than anything short of fire or earthquake. When you do a gaussuan blur in Photoshop, the machine just sits there cranking until it gets done. It can't do that will live sound. If it's not done with this note, it's going to miss the next one.

Koz

[kozikowski]

The jury is still out, by the way. You don't have speed problems. They usually show up as gritty sound or holes in the show. That's not what you have.

We'll see.

Koz

[haelen]

OK, thanks. I *would* try testing a different platform, but I Audacity is the best all round app for the work I do.

[steve]

I guess I could close some non-essential apps before recording.

Do try that.

[haelen]

I have today encountered another "glitch" (attached). No mic signal recorded, it seems - just this constant "ticking" effect.

Best,
Tim