AK T5p 2nd Generation|Astell&Kern,beyerdynamic」とのコラボヘッドホン『AK T5p 2nd Generation』発売日決定|Astell&Kern,Amazon.com: Astell&Kern Beyerdynamic Special Edition AK T5p Closed-Back Headphones with 2.5mm Balanced and 3.5mm Headphone Connector : Electronics,Astell&Kern,Astell&Kern,