If I put rechargeable batteries in the recorder, can I plug it in to the AC adapter or USB to charge the batteries?
No, you can not charge the batteries this way.
I can't hear the speaker, how do I get this to work?
Switch off the Input Monitor in the Menu > Monitor screen. Make sure the Speaker is switched On using the switch on the back panel.
I get an error message when trying to update the firmware.
You need to "unzip" the files that you download, ending in ".zip" These files are compressed by the server to make your download times as quick as possible.
On Mac OSX, double-click the file to expand it.
On Windows OS, right-click the file and "Extract All."