Arch Linux

fivedigits

Member

Registered: 2012-12-12

Posts: 13

Tascam US-122l crackling sound : USB 1.1/2.0/3.0 Issue?

I have recently switched from my old latop to a newer one, on which i want to use my Tascam US-122l audio interface in conjunction with jack2dbus and related applications.

I have compiled an RT-Kernel, version 3.6.1-rt3, since i was made aware of the kernel bug concerning this device in version later than 3.6.x. In plus, i am in the audio group, kernel starts with threadirqs etc. In short, i have exactly cloned the setup i ran on my old laptop, which is exactly the one proposed on archaudio.org.

Now here's the problem:

Although i do not experience Xruns, i get a strange crackling sound, that accompanies every audio signal routed through that interface.
(Speaking figuratively, it sounds like the signal is being routed through a snare drum, very unlike the classical XRUNS you get on a kernel that ist not fully preemptible.)

I have ruled out hardware failure by plugging the interface into my old laptop where everything works just fine.
The usb ports of my new laptop (2x USB 3.0) do not seem to be the problem, since all the other usb devices and even another audio interface from alesis do not cause any problems.

I had found a thread where someone reported a similar problem, that was essentially caused by the usb port running on USB1.1 mode although the interface requires USB2.0.
Sadly, i am not able to find it again but it seems to be my best bet at the moment.

Did anyone have similar issues or is able to tell me how to determine and set the mode (1.1/2.0/3.0) a usb device is running in?
I'd really like to make the switch to the new hardware soon, since the old one effectively limits me to 8-16 tracks.