Installing Mavericks on a new Mac Mini (end 2014) shipped with Yosemite pre-installed? Excuse me for my english, I'm french and I try to find a solution for my new Mac Mini buy in December. My new Mac Mini it's configured with Yosemite 10.10.0. and it's a problem for me because I use some professional music software like Cubase Elements 7 or Studio One 2, it's not compatible for the moment with Yosmeite. I want to downgrade and I read your post and I'm in panic because I view that not possible to downgrade my new Mac Mini in OSX Mavericks. I have created a external bootable usb key with a Mavericks in my other Mac. When i restart on my usb key bootable, appear this symbol 



It's the kernel panic when I try to boot on the usb key. I think it's mean it's not possible to downgrade on Mavericks with this New Mac Mini (end 2014) ?

Actually I'm in OSX 10.10.1, it's possible that the problem come because I'm in this version ?

Thanks for your help and your answers...
The general rule is, you cannot instal an OS on a Mac that is older than the Mac itself.
See Don't install a version of Mac OS X earlier than what came with your Mac

That said, Cubase 7 should run OK on Yosemite, though you will need the Steinberg Installer patch. I don't know Studio One 2 so I can't say on that.
Google did find this from Presonus about it.

Edit: I also found this, officially qualifying Studio One 2.6.4 as Yosemite-compatible