Oh, and by the way, the only thing I know that would make the empeg itself "beep beep" like that is the Hijack high temperature warning. Check to see if the empeg works OK on the AC adapter, and check to make sure the temp warning is disabled.

Anyone know if the temp warning setting is independently stored for AC/DC power?

If the temp warning is off and the empeg works OK on AC power, then I'd assume that it's something other than the empeg that's going wrong.