Dapper can only sync devices that show up ont he Mac as disk drives. Please do not buy Dapper if you can not already see your DAP’s storage show up on your Mac.
SyncMate is a 3rd party application that is written by Eltima Software and helps achieve this on AK devices like the 380,240,100II and 120II (The AKJr and some others do not require this)
Currently version 5.1.9 works with Astell and Kern Devices. You can download a copy from us by clicking here.
For some users the latest official build - version 5.2 does not seem to work.
Here is a full runthrough of accessing an Astell and Kern AK100II, AK120II and AK240 players via SyncMate so that they show up as drives on the Mac:
And here: