One I know of and used to have (and love) is Cool Edit 2000 - it is possible to get a free trial version, which has some functionality removed (usually the bits you want to use ), and I used that quite a lot for converting between formats. Alas it was on a since-deceased computer and I haven't gone back to look for it again, so not sure where you'd find it, or if there is anything else out there now. Try Tucows, I guess....