Some standard things to do is to run "aplay -l" to list your sound devices which should show your device. You can also run alsamixer and adjust the mixer settings and see if that helps. In all likelihood this is a USB 1.1 audio compliant device and should therefore be fully supported in Linux. In Jack you can try different settings of Frames/period etc. I usually safe default is something like 1024 Frames/period, 2 frames/buffer and 44.1 or 48 kHz. Look at the QJackCtl Messages panel when you run Jack and see if any errors are reported. Another slight possibility is that the USB connections is sharing an interrupt with another device, so try different USB connectors on your computer if you have more than one.
thanks for taking the time to reply! Your suggestions were very helpful
I had tried all the usb ports and there is unfortunately no difference, I don't know how to check and re-prioritize the interrupts though (or if that's even possible - I'm looking into it now). aplay -l lists the device and it is recognised as "USB AUDIO". Also, other similar commands which I found trawling this forum revealed no clues to me either.
HOWEVER, Looking at the qjackctl error messages showed that there is a stream of x runs when using the adapter and no matter what combination of settings I try in jack I can't escape them.
SO, to make sure it wasn't H/W issue, I quickly tried the device on a 2011 mac which worked fine for output but there was some issue with the input from what i could tell from the visual monitor (it showed a constant 50% sound input level, but speaking into a mic would make it shift slightly). I also tried the device in winxp running in virtualbox with AVLinux as a host. Both inputs and outputs seemed to work fine that way.
The audio chip is supposedly common, usb1.1 compatible and should apparently work ootb in linux so I'm a bit frustrated by this to say the least.
any more ideas?
thanks once again Varpa