Good consideration there with the Nuforce HDP, it's a great little Dac/Amp and it trumps the
E7/E9 combo quite easily for clarity and smoothness. Admittedly after having listened to the
E17 with the E9 ~ it's a nice improvement with the superior new DAC on the E17 but I'd
still select the HDP.
Another combo to consider would be the Audio GD NFB12 + Audio GD Digital Interface
a very nice solution for the price but it involves ordering directly from China. The NFB12
is quite competent but the USB implementation could be better, in that out of the box
it's not quite up to speed like the HDP but the additional Audio GD Digital Interface
rectifies all of those problems making it a very good value proposition, especially
since the head amp on the NFB12 is not bad at all.
As for the headphones - D7000 and HD650 if you are seeking a lush, non fatiguing
warm presentation that will never be harsh but the down side being that it could sound
like it lacks bite and attack at times (although with the HD650 this can be dramatically improved)
Yet to get my hands on the PS500 or T70 ~ but I'd bet my bottom dollar they will not
be as forgiving all round as the other two ~ and yet be more involving at times.
Must weigh it up ~ lush, forgiving, laid back or dynamic, involving, full of bite but
occasionally fatiguing.