So I'm looking for a good setup to use for many pairs of headphones, very different headphones at that. I'm not going to pretend to know what I'm talking about, so I'll just explain my situation. I use a laptop, so a DAC is pretty much necessary. I was looking more towards getting a tube amp, and I know there are some with the DAC built in. I currently have a Fiio E9+E7, but I am giving that to my brother.
Basically, I'm just looking for recommendations. I will be driving Beyerdynamic DT770 Pro's(250 Ohm), AKG K550's, Ultrasone HFI-580's, Sennheiser HD280's, and I will be getting Sennheiser HD 650's asap.
Budget is around $300, looking for a pretty versatile amp/DAC setup. If you guys could help me out, I would really appreciate it.