n4s heat: how to get 5.1 (Z906 connected with spdif/optical to PC)

hi mates,

before i had my pc analog connected to z906, 5.1 surround work always fine, but there was too many cables and whole the mess, i have changed 3x analog cable to one spdif/optical

now, i cant get 5.1 surround with n4s heat, other services works properly like netflix or Skyrim

how to get working 5.1 with n4s heat? plz help