I received my EP600 today, but I'm unable to update the firmware. EP600 reports "No firmware found", regardless of the USB device used, the format of the device, or whatever.
The recovery method also doesn't work. I found some posts on the micca forums about using the rear USB port, none of that made any difference.
Perhaps it is good that I wasn't able to upgrade, there are posts on the micca forums about low sound levels after upgrade to the newest firmware. All of those posts also have no resolution, despite pleas to post the old 220.127.116.11 firmware - which apparently isn't available anywhere.