My Line 6 USB audio interface is having problems (audio dropouts, loud noise bursts, etc…). What could be causing this and how can I fix it?

Most of the time USB audio problems are caused by data transfer interrupts on the USB stream that is feeding audio to the Line 6 driver for output to the Line 6 hardware. If your computer should fail to meet the system specifications required, the result can be a white noise burst from the Line 6 device. These interrupts generally do not affect most USB devices like printers, keybords, mice, cameras, etc… This is because these devices use a USB bulk mode of transfer and do not produce noticeable problems if data is interrupted.

– NOTE: there is no one-size-fits-all resolution to ensure proper performance of all Line 6 products (or all USB audio interfaces) on all computers.

Most USB interrupts can be resolved by one or more of these actions:

– Purchase a PCI-based USB card (for a desktop computer) or PCMCIA USB card (for a laptop). These cards often solve the problem of white noise bursts because the USB implementation on these cards overrides the USB built in to your computer. For more information on PCI, check out the following link:
http://en.wikipedia.org/wiki/PCI_card

– Adjust the Buffer Size in your Line 6 product’s Driver Console, which can be located in your Control Panel (PC…for Mac users, you can find your buffer settings in the recording software you are using, usually under your Preferences menu or window). The rule is: the lower the latency/buffer settings, the more CPU usage the software takes up and the more likely you are to experience noise. The newest version of the driver console will display a Buffer Size slider than you can adjust towards “Extra Small,” “Medium,” or “Large.” Try the “Medium” or “Large” setting first and see if that improves the problem. With the old driver console, you’ll see that your latency is defaulted at 2. Start by backing up your buffer to 20 and then work your way down to the lowest setting you can get to before the noise/static re-occur. Your objective is to have little or no latency while eliminating the noise.

– If you’re using a laptop, you’ll want to check the Power Schemes (PC) or Energy Saver preferences (Mac). To do this in Windows XP, go to Start>Control Panel>Power Options. Under the “Power Schemes” tab, change the power scheme to “Always On.” Make sure that “Turn off hard disks” and “System standby” are set to “Never,” then go to the “Hibernation” tab and make sure that Hibernation is NOT enabled.
On Mac, go to Apple Menu>System Preferences>Energy Saver and make sure that the slider for “Put the computer to sleep….” is set all the way to the right for “Never.” Also make sure that the checkbox for “Put the hard disk(s) to sleep when possible” is NOT checked.

– USB hubs can sometimes cause noise bursts, audio interrupts, and other odd behavior. If you are using a USB hub and experiencing these kinds of problems, disconnect the hub and plug your cable directly into a USB port on your computer. This problem seems to occur especially with Mac users. Make sure you are connecting directly to your computer and not to your keyboard or other device, as this acts essentially like a USB hub.

– On some CPU configurations, actively using wireless networking/connectivity while streaming (recording/playing) computer audio via Line 6 USB devices can sometimes impact the fidelity of the audio streams (ie, noise or artifacts are heard in the audio while using wireless connectivity). For best results, disable and do not use wireless connectivity while recording and playing audio over the USB bus.

As noted above, there is no one solution that will work for everyone. However, there are many steps that can be taken to eliminate or avoid these kinds of problems (the steps above are a perfect example). We have compiled a collection of potential solutions into one document, the PC Optimization Guide for Windows XP. If you haven’t already, we reccomend you read and follow the PC Optimization Guide to ensure that your system is streamlined and optimized for audio performance (and if you’re a Pro Tools user, make sure you also follow the Pro Tools addendum to the guide).

You can find the PC Optimization Guide here:

– https://www.sweetwater.com/sweetcare/ts/detail.php?Index=30058
(Knowledge Base Article 30058)

You can find the Pro Tools addendum here:

– https://www.sweetwater.com/sweetcare/ts/detail.php?Index=30083
(Knowledge Base Article 30083)

Knowledge Base