Headphone amplifier with XLR output for monitors
I've been reading a lot about headphone amplifiers and tried very few so far. I narrowed it down to a few options that match my setup and I would welcome any feedback on this.
Setup: AKG K701 headphones + Macbook pro (latest model, which some say has a good DAC) + Tannoy Reveal 501A active studio monitors (so they have built-in amps) .
My main requirement besides improving the sound quality (the volume is fine, I just care about the quality). I would like to be able to easily switch between headphones and the monitors.
The DAC is optional, AFAIU the Macbook pro's DAC is pretty good and it's unlikely Spotify or Apple Music will start playing DSD files. I also don't like that with an external DAC I cannot control volume with my keyboard ...
Budget: I would not like to spend more than $400 for my first amplifier.
I've narrowed it down to a few choices:
There are a few others like Fostex HP-A3 and Korg DS-DAC-100 and the very expensive Cambridge Audio Dacmagic 100 or Dacmagic Plus.
I really appreciate your feedback or suggestions for alternatives. Without trying these, it is really hard to make an informed decision. Thanks!