Thanks Andy, I forgot to mention that you need to turn the volume to about 50 in high gain to power the 702s ( my normal listening is about 20-30 with iem or v-moda m100 ).
I've just plugged N5 into my Schiit Vali and k702s are really singing now !!!
Listening to Marc Cohn - Walking in Memphis is sublime, the Vali / N5 combo just has the most awesome synergy with the k702s. The soundstage and placement is amazing !
Shawn Mullins - Lullaby is, well ditto !
Billy Idol - Catch my Fall - sounds as good as the first time I heard it live at the Milton Keynes Bowl ! Absolutely brilliant....
N5 is making me revisit all my old music again

I just replayed About the Young Idea -The Jam, listening to it with the Vali combo - Town Called Malice and there it is ! Paul Weller's voice is there front and central, not at all recessed as it was with just the internal amp on N5.
I'm not saying that the internal amp is lacking at all, just it seems to need a little more power with The Jam and that type of music ( maybe it's my age and / or ears ) ???