Currently Being ModeratedNov 22, 2013 8:12 AM (in response to lagstrom)
I have the solution. I called the support and they said that the new USB drivers on the new mac's are not configured to work perfectly with the scarlet interfaces. So he send me a download link and instructions. I'm so happy this worked. Here is his email back to me, hope it helps you!
"Thanks for your call and sorry to learn of the problems you are having with your Focusrite product.
Some users have reported experiencing audio glitches and drop outs with the Scarlett range of interfaces since updating to OSX 10.9 Mavericks. If you are experiencing these problems with your interface, it is possible to utilise Apple’s USB audio driver by downloading and running the class compliant mode application below, while we investigate further.
Please note: After the class compliant mode application has been unzipped, please right click on the application and choose "Open". If you do not do this you may get an error message from the Apple Gatekeeper service
Please feel free to call us back on +44 1494 462246"
Currently Being ModeratedNov 23, 2013 7:29 AM (in response to Traveling John)
I'm glad it helped you but that did not help me. Looks like there is som incompatibility issue between imacs with fusion drive and usb audio interfaces using 10.9 Mavericks
Currently Being ModeratedDec 9, 2013 8:47 AM (in response to cauchy)
If you are running OS X 10.9 Mavericks this is the solution for that noise problems:
For me it worked fine!
Currently Being ModeratedJan 19, 2014 2:49 PM (in response to lagstrom)
I have also a fusion drive in my iMac. After I installed the new USB2.0 drivers I got the cracking noises only when I pushed the record button... the noises faded in after a short while... When i'm not recording the sound is fine.