random Ultrlite sound card distortion???

[mlanson]

After trying to get this card to work for 2 weeks on a PC, I'm almost there...

Now the only issue I'm running into is that out of no where, the card will start distorting until I close and open the media player or ableton that is playing the audio.

It's a real drag to stop what I'm doing and close the application every time it happens.

Does this sound familiar to anyone?

Thanks

[guidon83]

Hi I'm having the same problem with a MOTU Microbook on windows XP SP3.. anyone has any idea of what to do ?

[1nput0utput]

Have you tried raising the audio I/O buffer size? For the UltraLite, the buffer size setting is in the MOTU Audio Console program. For the MicroBook, it's in the Setup dialog in CueMix FX.

[dburns01854]

If increasing the buffer doesn't help, make sure you have a genuine Texas Instruments (TI) chip in your adapter.

This doesn't cause a problem for everybody, but in my case my laptop ONLY works with the UL on a TI cardbus adapter.

[guidon83]

Hi

changing the buffer size makes actually the difference: the higher the buffer, the later the distortion shows up. However the problem turned out to be the integrated wifi card of my laptop. If I disable it and boot the system with no wifi connection, The motu card will work fine without any of the mentioned problems. I also had confirmation from MOTU tech support:

Hi Guido,

Sounds like you've found the problem, it's a rare yet annoying problem we see in Windows machines. Sometimes another driver, unrelated to MOTU, takes too long doing whatever it does. When this happens there is little we can do on our side, our driver is starved too long and simply falls behind because it get's there too late. Typically the worst offenders are drivers for network adapter cards, like yours.

[j_e_f]

Aha. I'll bet your WIFI card, and your MOTU device (or more accurately, your PC's firewire port) are being told to share the same IRQ (by your BIOS).

Some BIOS allow you to assign IRQs to specific devices. Get into your BIOS settings and see if there is such a feature, to give your PC's firewire (1395 network) port its own IRQ. If not, then try moving your WIFI card (assuming its a PCI card) to a different PCI slot. This may cause your BIOS to tell the WIFI to use another IRQ (or share an IRQ with a different device).

Once you get your firewire port not sharing an IRQ, your problem should disappear and you can lower your buffer size (ie, reduce latency).