insigma

Hi all, Just joined the forum in a hope that someone can help me out here. I seem to have bought a "Sampling Rate Converter" made by Pioneer about 10 years ago for the MiniDisc (or so it says on the top of the device), and i have no idea what it is for. Anyone know what I one would use a Pioneer FS-F21 Sampling Rate Converter for? I've had a dig around on google, but everything seems to be in Japanese. Thanks!