This answer applies to R4 Mk3
R4 Mk3 Supports the following formats and bitrates.
It is important to ensure that only compatible music files are stored on your memory stick or CD-R. Unrecognised files are likely to cause interruptions or cause R4 not to read the downloaded data. Also you should ensure that memory sticks and micro hard-drives are formatted to the FAT32 standard as NTFS is not compatible with R4.
If not, please do not hesitate to contact us directly on +44 (0)1702 601410 or by using the enquiry form on our contact page.