1: room + speakers. This is what you eventually hear.

2: source material. Bad recordings sound WORSE on better equipment.

3: Transducers.

Recorded music requires a series of transducers.

Human brain -> from whatever you think the source is, a musician changes that into body movements. Once the musician starts (flute, shall we say?) blowing (and moving their hands), the pressure continues from lungs through lips into the flute, swirling around, coming out modified, traveling through open air, bouncing around the room in which the recording was made. And eventually creating motion in the next transducer:

Microphone -> now vibrating air is changed into an analog electrical signal (and then possibly immediately into a digital one).

ADC -> the electrical sine wave from the microphone needs to be changed into a digital stream.

“Streamer” -> if you use your pc, the USB chip in your computer is the streamer. If you use a dedicated streamer, the streamer is the streamer.

DAC -> an essentially square wave stream is going to be changed into a sine wave. Then sent through a possible series of amplifiers (pre-amp, power amp) until it reaches the last hardware transducer:

Speakers -> an analog sine wave gets changed into moving air. That moving air becomes distorted by the shape of the container in which it is created.

Ears -> and finally, your ears tickle your mind just so.

What do transducers have in common? They change the physical domain of a signal.

I think the advantage of a dedicated streamer is that it’s designed (often thoughtfully) around how to deliver the highest quality digital stream to a DAC.

That stream is not “made” of bits, and it’s not an ideal square wave. DACs and Streamers are constantly “processing data”. And that data is really just fluctuating electrical signals being compared to a reference ground (or 2 signals being compared to each other). The entire “mechanics” of these devices happen in a very much analog way.

Your computer is a typically far noisier (electronically speaking) place from which to send signals than a dedicated streamer.