the CD8400 is located between the predecessor, the Mk 1 and the CD903: Except almost identical to the MK1 (who has taken over as almost all Philips TDA1541-Clone to 100% Philips -circuit boards and innards with a separate front panel), it has the same motherboard as the CD903. The main Board is a private, in the arrangement of the sub-assemblies "superior" Routing with its own output stage on the Basis of a very pleasant-sounding double-OPs LM 833 for U/I Converter and the Filter /Buffer. In contrast to the CD8400 Mk2, the CD 903 has a highly selected, more linear TDA1541 - "S1" DAC instead of a normal one.