I have a Hifiberry Amp2.
https://www.hifiberry.com/blog/introducing-the-amp2-more-power-higher-sample-rates-more-affordable/
Currrently on the mantle hidden among the Christmas decorations, it's basically invisible. I use a recyled laptop power supply and only one wire to the nearest wall outlet is detectable. The amp drives 8ohm bookshelf speakears. Volume is quite sufficient for a large family room. Typical listen at 20-30% on the runeaudio app.
I'll take a look at the justboom. Looks like they share the same Texas Instument chip. Eventually I'll have one of these in every room plus the garage.
