Hey guys, so I was looking at two possible amps the Hifiman HF2A or the Bellari HA540. My budget is about $300 CAD. I own some M50's and some hd558's, and I know the m50's won't benefit much from an amp but i want one for the 558's. The amp has to be able to power the Dt 990 PRO 250 ohms well and be mostly future proof because I don't really want to upgrade again for a while. the next phones i get will most likely be the HE-400's, but that won't be for another year of so. (as a point of reference, I will be ordering from the headphone bar in Vancouver, so feel free to suggest alternatives from their site.) Thanks!