headphone amp recommendation(s)?

anyone recommend a headphone amp?
or would one of these be better on the main out?

this is for using a native instruments audio 10 for producing using headphones.
when having the output of Ableton running at around -6db the headphone volume isnt enough.

the other outputs of the audio 10 are really strong if they are plugged into active speakers, when I'm at someone elses place.
I dont use speakers. just my headphones.

I also have a DJ mixer which the mixer part is analogue, and therefore you get the analogue warmth added to anything, which is fine for DJing, but not for producing.

so I'm currently swapping my headphones between my mixer and the NI audio 10.
any solution?

routing the mixer through the audio 10 is not a solution, as I connect the audio 10 outs to my mixer for DJing.

headphone amp suggestions.
not too expensive.

I think I will get one of these for the output. so that the volume to the powered speakers can be controlled:
https://www.amazon.co.uk/Fostex-PC-1.../dp/B0058B1T5G

and then one, of these to select the output from my mixer or the audio 10.
https://www.amazon.co.uk/gp/aw/d/B00...0T0C7D8AHK117Y

Define not too expensive and what are the headphones you're using.

https://tangentsoft.net/audio/cmoy/

What headphones are you using? The Audio 10 headphone output should be more than enough to drive most headphones out there for home use. If you drive your headphones too hot you'll get ear fatigue quite faster which will make mixing/mastering way harder and eventually cause hearing loss.