Astell & Kern AK Jr High Resolution 64GB Music Player - The Starting Point of Music. Although previous Astell & Kern models were designed as portable devices, the relatively large size made them less convenient for some. The AK Jr’s compact design delivers the highest sound quality while fitting comfortably in your pocket. So buy this Astell & Kern AK Jr High Resolution 64GB Music Player - The Starting Point of Music Now £399.00.