The landlord can consider the following combination: 1. Olive 4HD: Songs can be stored wirelessly, including CDs, and the frequency can be automatically upgraded to 24bit/ 192Hz, which is $230,002. PS Audio Perfect Wave DAC: It supports external hard disk, digital input of 32bit/ 192Hz, and the automatic frequency can be as high as 32bit/ 192Hz, $370003. MacMini+Weisdac2: MacMini is mainly used for burning CDs, and Weisdac2 supports 24 bit/65438.