Well...do you like the way your DT880 sounds? That, more than anything else, is the most important thing to consider with any audio device. The DT880 is often considered to be an excellent value, but it also has a sound signature (bright-leaning neutral) that some people love but others just can't get on with, so it's not going to be a universally good or bad choice. If you're asking if it's worth putting upgrades into, I'll admit that I'm a known skeptic of a lot of the benefits touted by cable/amp/DAC upgrades, so you can take what I'll say with a grain of salt, but I would say that nothing source- or cable-related is going to fundamentally alter the way the DT880 sounds. If you really like the DT880 and want to get that last little bit of performance out of it (real or perceived), then go for it. It's certainly not going to sound worse with higher end equipment behind it. But if you're hoping for a drastic transformation, you might want to look for something that comes closer to your sonic preferences even before you start upgrading the rest of the audio chain.