Official comment
hello Hayley,
You can connect the toraiz to your mac but you have to put the unit in USB Mass Storage Mode in the utility menu. See link below for you details.
Once the toraiz shows up on the computer you can transfer files/samples into the unit.
Hope this answers your questions. thanks
http://faq.pioneerdj.com/product.php?lang=en&p=TORAIZ_SP-16&t=faq&c=search&qq=internal+storage