- Receivers have terrible power amp sections
- Receivers combine the multiple power amp sections in the same chassis as the dac/preamp sections, etc (terrible idea).
The path to high fidelity in multichannel music is going with a no compromise separate preamp processor such as the Marantz AV10 (lot more expensive than your receiver) and separate power amps (Marantz amp 10). The poweramp should be separate. Ever wonder why this preamp processor+ power amp combo retails for 14k and the receiver is less than 2k? The above mentioned should give you a hint. HT is no big deal since the ear is not scrutinizing as it is with movies like it is for music. A receiver should be fine for movies.
You shouldn’t worry yourself with 2 channel DACs or streamers. If you use any of the Marantz’s features such as bass management, peq, etc, a purist DAC’s analog output will go through a ADC conversion inside your Marantz unit. Besides, your unit with all its features can beat the crap out of most of them in execution, if you can set it up right.
For now, you could use your receiver’s pre-outs to separate power amps and not use the receivers internal amps. You may be able to turn it into just a preamp processor by turning on a "preamp mode". Newer Denon models permit this...think your Marantz may as well since all these brands are "Sound United" these days. This would be the intermediary step to higher fidelity before you can get to true separates.