I just put in an order for the onkyo dp-X1 to use with the k10's. Anyone have any experience with this pairing or think it will be good?
I do plan to use and compare both balanced and SE with it.
Also as a side note: what is everyone's opinion on the basically non existence of class a amplification for portable setups. Does it matter?
That is my primary setup, and it sounds fantastic. The DP-X1 was built from the ground up explicitly to play in balanced mode. When it comes down to SE vs balanced, implementation is key. The DP-X1 was designed around its balanced output, and the balanced output sounds significantly better than the SE output. I have a cable that allows me to trade out the cable connection to 2.5mm TRRS, 3.5mm TRS, 6.34mm TRS, XLR, and mini XLR. I have had my wife trade out the connections on the cable / player so I could A/B test them (it was behind my back so I couldn't see, and I didn't have a different cable so I couldn't tell when / if the connection to the player was changed). I got it right 30 times out of 30 tests.
The balanced output on the DP-X1 sounds better to me than the SE output. That doesn't mean that it's the same on every single device, or that balanced is inherently better. SE on the Hugo is sublime, and I assume it is on the Mojo, as well, but I haven't heard that. It really does depend on the device. Actually, I generally preferred SE to balanced on the AK240 that I briefly demoed, and I later learned that the SE connection was a direct connection and the balanced was attached by a small ribbon cable. That doesn't mean anything, other than that the balanced connection wasn't the primary design consideration for that device.
So, on the DP-X1, you will enjoy the SE output, but I really do recommend going with a balanced cable eventually. It is a very good upgrade on the sound. You'll enjoy it!
On your last point, I don't think it matters too much. Portable gear generally doesn't require that much power, and it sounds great without Class A amplification. It's just not necessary.