Yes to Crack (while I was writing Stan posted before me so..I should have quoted my reply). Me too no Speedball (but independent from this decision, I read that some (minority, only 1-2 posts somewhere) didn't notice an improvement at all, or even rather the opposite with Sp.).(not saying Sp. is bad) I hope indeed that it's a good amp. Need still a DAC too. It's going to be the Modi, will need again to wait for it.
The Modi should work just fine. It's based on the AKM4396 chip; same chip is used in the Audioengine D1, which I am currently using with the Crack.