I have a PCM-10 that I've had for years, but I haven't used in a bit. I thought you could change the file size. I want to set it for MP3 128 with a 64 G card in it and just let it go while I'm away. I thought for sure I could change the file size, but I don't see where or I am mistaken. It seems 2G file size is it. I'd like 500MB. Thanks Much.