I use this one in combination with my iPod Touch 4G: http://www.amazon.de/FiiO-L10-Line-out-Verl%C3%A4ngerte-version/dp/B005DK08X6/ref=cm_pdp_rev_itm_title_3
And this one with my MS Surface 2: http://www.amazon.de/gp/product/B007SUQUAE/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
With neither I have background issues on the NX1 (Sony MH1 nor Beyer DT 880).
EDIT:
Haven't tried the stock cables though.
you need to have 32ohm or higher when using this amp to not have hissing. Thats why I feel that the havi pro iem's are the best budget combo for this amp.