[oogabooga]

Twice over the past three days, I've been listening to music when, all of a sudden, the music becomes HEAVILY distorted (and louder) - sounds like static at first, but when I turn it down and my ears recover I can hear that it is heavily distorted music - like someone has mixed 90% static with my tunes. If I stop the music in iTunes, I don't hear anything, but when I press play again the distortion is still there. Unplugging/replugging my DAC/amp gets rid of the problem... until it happens again!

My audio path is:
Macbook Pro --> USB connection to XM5 (BB PCM2702) --> triple.fi 10

I know it's not related to iTunes as the static applies to sound from other programs as well. Any thoughts? Anything I should try to next time it happens to "diagnose" the problem? Any Mac users experience similar problems?

Thanks!

 

[Andrew_WOT]

Have wi-fi card by any chance?

 

[oogabooga]

Yes, built-in wifi, built-in bluetooth, and a separate USB dongle for wireless kb/mouse are running. No data goes over the wifi though - I use it at home (where I don't use the amp) and don't bother turning it off at work (where I use wired ethernet).

 

[oogabooga]

It happened again. Pausing and restarting the music got rid of some of the static, but not all (the music was more audible but still had a good layer of static on it). While the staticy music was playing I disabled my Wifi and BT - no effect, static still came through. Only removal/replugging of the USB fixes it.

It wouldn't be so bad except the static is LOUD!

 

[suicidal_orange]

Just a thought, but is the DAC too near the exhaust fan of the Macbook so overheating? Not sure it could happen but electronics don't like heat.

Try another USB port if you have one, preferably in a block with nothing else - if it's internal noise or another device on the same USB that might fix it. Take note of what you are doing when it next happens - is there a lot of hard drive activity, network traffic, fans spinning up... anything that might be triggering it?

If you have another computer use the DAC with that for a bit (long enough it would have happened), see if it's the DAC thats causing the problem or the Macbook.

Other than that as I've never used a Mac I can't really help, but more info may be useful. Or it could be a common Mac issue in which case it wont...

Hope it gets sorted soon as it doesn't sound nice to be blasted with static at random - must be very annoying!

 

[oogabooga]

Sadly no - it's far enough away that heat's not an issue. I also can't identify any special event - it generally happens while I'm surfing the net and listening to iTunes! It's already on a dedicated USB port - I'll try using one of the ports on my monitor USB hub and see what happens. Nothing out of the ordinary occurs when it happens

This has never happened before using my USB TBAAM, optical Z5500s, or onboard Mac Audio, so I guess that makes me point my finger at the DAC... but I'm skeptical b/c I blamed my last problem on the DAC and it turned out to be settings on the computer!!

On the weekend I'll try the XM5 on a different computer (perhaps a PC) and see if the problem reoccurs - thanks for that tip, suicidal_orange. I'm also considering a dedicated optical-in DAC, since I've decided to bankrupt myself since joining head-fi!

 

[audioengr]

Do this:

1) remove all other USB device, even a mouse.
2) give your player highest priority in task manager
3) turn-off virus scanner
4) disconnect from internet

If it still happens, then you may have a problem with your DAC.

Steve N.
Empirical Audio

 

[oogabooga]

Damn. Happened again, on a different USB port, playing VLC, but still on my MBP. I'll have to try it on another computer on the holidays.