MBP 2014 retina, forcing usb 3.0 to work in 2.0

Dear all,

I am having big troubles to make work my audio interface (Korg Kronos USB 2) in my new Macbook Pro 2014 retina with Yosemite. I have tried with a Macbook Pro 2010 with Yosemite and works perfectly (both devices are 2.0).

However, seems there is a an issue between USB2 and USB 3.... have tried switching ports, using 2.0 hubs (powered and unpowered) and results remains the same: audio drops, clicks, etc.

Question: Is there a way to set a USB 3.0 port to work as 2.0 only ? where exactly into system preferences?

Question 2: is there another way to make USB 2.0 devices work properly in USB 3.0 ports?

Many thanks in advance...

Kind regards