Is there a good combo for Audio interface with XLR (obviously) that can also be a decent amp for my 6xx? Or should I just look for on and the other separately? And if so do you guys have any decent recommendations for amps in 100$ range?
Most audio interfaces have a headphone jack that is good enough for monitoring.
The Motu M2 is above average concerning headphone out for audio interfaces, but not anywhere close to headphone amps in performance.
Since I don’t have experience with either, I can’t give much advice.
What do you need it for? Recording vocals/instrument, etc? Streaming/Video production?
I need it for microphone connection and monitoring ^^