It varies depending on the compression level devs use and how lazy they want to be. This one is apparently high quality. For example, the Ace Combat 6 demo had a somewhat saturated sound quality on its bgm.
FF CC life as a king songs as genh http://www.mediafire.com/download.php?0rwukqmwmnz recorded line-in of the brsar wad player and made looping with genh
Bxaimc, you know what's better than the N64 version of Re-Volt? The PC version's Redbook audio.
Also, I understand that looping songs means a lot to you. But is it really worth the quality loss? ADPCM /= PCM. What we really need is a metadata type of file (like POS from Ys I+II Complete) that we could use with vgmstream to loop generic PCM.