I bought and returned a DX5 on Amazon when I had purchased Aeon 2 Noires. The DX5 just couldn't drive them, which was shocking because what Dan Clark Audio recommended me as min power requirements was far exceeded by the DX5 in high gain setting. Some people on this forum told me it was probably current-limiting that I was running into. Just sounded awful at higher volumes on really bassy sections, and I still had around 5dB of room to increase the output, so it wasn't even that I was at the peak output.
Question is, is the DX7Pro+ going to have that issue? Not that I specifically care in that I returned the Aeon 2 Noires (I'm done with DCA for good, the Stealth seems great but if it's even harder to drive than the Aeon 2 Noires, no thank you, learn how to design a more sensitive headphone).