DT990 Pro

Hello, recently I have bought the 250 Ohm version of the DT990, and I have decided that I wanted to buy an Amp and Dac. I was looking to buy the Schiit Magni 3, and Modi 3. But I was wondering if I could just buy the Amp and connect the Amp from Rca to 3.5mm into the back of my PC. What I am...

(New to the audio scene so please correct me if i'm wrong etc) I was wondering if the FiiO E10K Olympus would be enough to power music/games/movies for the DT990 Pro Headphones. As far as I'm aware it will only power 150ohms but wont the 250ohms be to loud for anyone anyway? Will I notice the...