Astell&Kern players officially support up to 1TB microSD cards.• Older generation models officially support up to 512GB SD/microSD cards: AK3xx series, AK240, AK1xx Series, KANN, AK70 MKII, AK70, AK Jr.• Cards should be formatted in FAT32.• [Disclaimer] Use of external memory cards is at user's own risk.  Astell&Kern is not responsible for lost or corrupt data stored on 3rd party manufactured memory cards.