Mains headphones amp for a 3.5mm jack?

[Pawnless Endgame]

I'm running a Nintendo Switch off HDMI and a PC off DP, and my headphones get the sound from the monitor's 3.5mm jack. I now have a new monitor and the HDMI/DP sound isn't anywhere near as loud. I checked in the monitor's menu and the sound is already at 100%. The sound must be gated, some health & safety thing on newer tech I guess. I tried using a 5V portable amp which drove the sound up slightly but not enough for me as I'm hard of hearing. I think what I need is a 12V or 24V mains amp. Have anyone got one? Please let me know what you use for your PC/console with headphones set-up.

P.S. if I plug the headphones directly into the Nintendo Switch or PC, then I get normal volume fine. Ideally though, I would like a single point of contact for sound hence via the monitor's 3.5mm jack.

Thanks

 

[Pawnless Endgame]

Thanks! I forgot to say my budget, but £100 is about right for me.

The Schiit is out of stock according to their web site, but I have found the JDS on Amazon no probs. That looks ideal for what I need, so thanks again.