So I informed myself a bit and found the Hifiman Sundara. First I am not sure to buy the Hifiman Sundara, I read they are great for 350 Euros and also I prefer to get an open back headphone. If somebody have any suggestions for a better headphone around that price, let me know. Secondly: If you have any good Ideas for a good AMP/DAC that matches the headphones for a Desktop Computer (not portable) let me know.
So for my Budget, I don’t want to pay more then 600 Euros for Headphones and AMP/DAC. I would like to keep the budget at 550 Euros. I live in Europe, but I can order stuff in the USA till the beginning of Christmas holidays.
For the use of the headphones, I mostly hear Music, so Hip-Hop and to study I hear Lofi and Opera music (not sure how to call it, so stuff from Mozart and Grieg). I also play fps games, but just at the weekend, so 65% music and 35% gaming.
Thank you for your help in Advance.
firstly, welcome to HFG, haShinui!
consider the iFi Zen options…especially if you will buy a balanced cable for the Sundara to get the extra power that comes with.
So I watched the iFi Zen DAC v2 and it seems good, but it is just a dac, do I need a AMP for Hifiman Sundara, will the amp better the quality and are tube dac good?
iFi has several options to consider with their Zen series. there is the Ifi DAC v2, which is both a DAC and amp with single ended output (6.25mm) and balanced (4.4mm Pentacon). then they have their Zen Signature DAC, which is just a DAC, which is supposed to pair with the Zen CAN, which has a couple of options in it as well. I believe buying them separately gives you about 20mw more power than the combo unit.
I have the v1 of the combo unit and I love it! 
Yea thanks I will look into it, I maybe want to experiment with a tube Dac.
xDuoo MT-602 amp
I think you mean tube Amp. and that’s why I recommended the iFi ZEN as it uses Burr Brown chips for it’s DAC and they are known to be very warm sounding, which the Sundara responds to well. being the Sundara has low impedance, you would look at a hybrid tube amp then.