I've had a reply from Nik and there is no fix and they don't see a sound issue, although they will monitor to see if others are having issues
I was really hoping that there was an improved driver around for the Linx integrated soundcard or tweak, it seems there isn't, a great shame as I know the sound can be improved with the likes of the DFX audio enhancer.
I have a Nissan Note car with audio input and I compared the Linx output in the car with and without the DFX audio enhancer, the difference was vast, try the DFX trial on the Linx for yourself to see (hear) and this is with limited light processing, the full DFX version has more power/features, I just hope it doesn't blow the 0.8 W speakers!
Looks like I have to fork out £20 to improve the Linx audio, which is a shame
A bigger shame would be someone posting a fix/tweak found after I'd spent my hard earned cash.
Please speak up now or forever hold your tongue lol