Usually receivers are intended for passive speakers, a lot of the bulk is for housing and cooling amplifiers.
If your speakers are active and don't need an amp, you can use a HDMI audio extractor, those are pretty small (mine is about half the size of my phone)
If your speakers are active and don't need an amp, you can use a HDMI audio extractor, those are pretty small (mine is about half the size of my phone)