yeah I have something similar, as far as I know it has a separate Famiclone board inside (even though the Firecore hardware is actually an emulator running on some ARM based chip, so it could easily emulate the Famicom too.. don't ask me why AtGames do what they do, theyre a weird bunch). The sound seems OK on mine, they're mostly Nice Code games though.
the MD compatibility still sucks though, I was hoping I'd be able to play the Legend of Wukong English version on it because its the only undumped Mega Drive game I own, but it just flickers between a SRAM error screen and the Famiclone menu when I try it.
I want to get hold of one of Qi Sheng Long's portable MD clones, since hopefully they have TecToy chips in them like their 2-in-1 and 3-in-1 systems, but I can't find anywhere selling them. I asked volumerates and they said they'd look into it, no results yet though.