I've decided to pair my beyer DT 1990 Pro with an amp but I need a dac too because I'm also into music production. I came with the idea of buying darkvoice 336se all cool when I started seeing that I have to change the tubes, then make a 72h burn out without listening and other things. Nobody got time for that! Assuming that my setup was darkvoice 336se ($600) I needed a dac for the music production, so I would spend $200-250. That's $800-850 just by buying the dac and amp. Add the new tubes you must change and you hit $900-1000. So, is this setup great or I should not waste time and directly buy WooAudio w7 for $999 (new 2nd gen.) ?