Not only do you have a new mobo and a cheap dac/amp so there shouldn’t be a difference, but you’re also using a gaming headset which in my personal experience doesn’t scale with anything. I’m more blown away by your experience than you are lol, but if it makes sense to you then that’s all that matters.

IMO the Sundara is a good upgrade, it has deeper bass and a more energetic sound. I think the HD560s sounded too flat in comparison.

Another option is DT 900 Pro X. I think it sounds more enjoyable in pretty much everything.