Beyerdynamic has a long track record with reference headphones. My very first pair was a DT 250, flat and fully modular, and it still works perfectly after 22 years. The DT 770 PRO's cable isn't replaceable, which is a shame, but it's a good match for interfaces that don't pair well with low-impedance headphones, like the Scarlett 4i4 4th Gen.
