Hi, rifasha.

I just bought HD668B and also own a PCM2704 based DAC, but my DAC left at other places which only after this weekend I can try it.
I also get a custom cable, but from another person though. (ssyycc) Haven't really tried them though.

Did you burn-in for moment before your first impression ? My first 'out-of-box' impresion wasn't good, but after like 5 hours of playing, its alot better. Alot claims that it become better with more playing, so i'm looking forward to it.

Did you get any better DAC ? I'm also thinking of getting better one, but have no idea which is good and cost-wise not expensive. (good performance-to-cost ratio, just like superlux headphone ! )

Have you replace the short cable or do some modding ?