as of 4/2015 OS X Kindle App: Where are the books located?

After I updated my Kindle for Mac app 2 mos. ago I can no longer find the azw book files on my Mac to convert them so I can read them on my KOBO ereader. I use to find them in a My Kindle Content file but that has disappeared. I have Ult. DRM & Calibre but they won't work without the azw files, and I can't find them on my mac anymore. Can anyone help me? The answers on this site about this are years old & do not apply to my problem.