Play music from laptop over WiFi to existing audio system: how?

@lowoverdrive: for < $130 you can build your own with a RaspberryPi 3B+ ($40), HiFiberry Dac+ Pro ($45) as HAT, and all that in a HiFiberry steel case ($30). Throw in a few copper heatsinks for the RPi 3B+ board. ($5).

Then (all free): Volumio as your primary OS _and_ streamer/player, and BubbleUPnP for Android as your control point (or some other control point app - will talk to Volumio via UPnP/DLNA), and your existing laptop basically as NAS (or control point + NAS).

Fun lil'project, great network HW on the RPi 3B+ (Gigabit ethernet and 802.11ac wifi), Hifiberry DAC+ Pro hard to beat for ~$45, Volumio dead-simple ... and all kinds of entertaining and useful extension later (like: set up for multi-boot using Berryboot, then switch bet. Volumio, OSMC/Kodi as media center, and Raspian for all your Linux stuff).

@usery I know about the RaspberryPi and HiFiberry Dac. I’m concerned that won’t give me the sound quality I’m seeking.

However, the approach of using a general purpose computer running some Linux flavor has become my preferred option. I just decided to go with more powerful CPU’s and better DAC’s.

In the last few days I extended my system to whole-house music playback. My favored music player is cmus, something I just discovered while working on this project:

CMUS (C* Music Player) - A Console Based Audio Player for Linux https://www.tecmint.com/install-cmus-music-player-in-linux/

Each room now has a laptop (connected via wired Ethernet), a USB DAC, a power amp and speakers. Here’s how it is organized.

- home network extending to each room, where I have:

• laptop
  
• USB DAC
• power amp
• speakers

each laptop which is connected to speakers runs:

• Linux
• PulseAudio
• ssh

one computer on my network also runs:

• tmux
• cmus

The above computer has all my digital music files too.
I can control playback from any computer on my network, including a laptop over WiFi. I could also use my phone as a remote if I wished, but so far I haven’t felt the need.

The beauty of this approach is that it is very simple and very flexible. The simplicity surprised me.
.

lowoverdrive 

... I know about the RaspberryPi and HiFiberry Dac. I’m concerned that won’t give me the sound quality I’m seeking.

You may be right. But don't underestimate the Raspberry Pi. When configured with the Digi+ S-PDIF HAT and run into a high-quality outboard DAC, it can produce astounding results - especially for the money.

Each room now has a laptop (connected via wired Ethernet), a USB DAC, a power amp and speakers.

That works too and also fun, though cost may be +multiples of RPi/HiFiberry approach.  What DAC/s are they?

@usery> What DAC/s are they?
Here are the DAC’s I’m using. I have a different one in each room:

• Onkyo P-3000R (preamp + DAC)
• Oppo UDP-205 (preamp + DAC)
• Yamaha AS-801 (amp + DAC)
• Focusrite Scarlet 6i6
• Native Instruments Komplete Audio 6
• Focusrite Scarlet 2i2

Basically, I just used what I had. There is a large range of quality among my DACs. I have the best equipment in the rooms I care about most. (My speakers also range from inexpensive to Maggies + dual SVS subs in one room.)

I can imagine that the HiFi Berry DAC+ Pro might rival the Focusrite Scarlet 2i2. But I would be surprised if it is anywhere near the Onkyo or Oppo devices. (Of course, those devices are much, much more expensive as you and others pointed out.)
Another drawback of my system (compared to the RPi and HiFi Berry DAC) other than cost is size. I did not have to buy hardly anything in order to implement this system because I had the laptops, DAC’s, amps and other equipment. I had enough to do multiple rooms. So cost was not a factor for me. But all these pieces of equipment are fairly large. I am interested in compact components that do not represent a compromise in sound quality.

I’m still looking for the ideal compact DAC and amp for some of my rooms. But I think I will continue to use laptops instead of the RPi. It is possible to buy very good used laptops on ebay for very little money, and these laptops offer much greater performance and, I think, a much better value.

Laptops are also very practical in that it is nice to have a screen and input method (touch screen or keyboard) in each room so anyone can easily change songs, playlists, etc., from any room. I guess most people today do that via a tablet or phone, but I could list dozens of ways in which having that laptop there in the room is much more convenient and flexible -- at least for me. While I could add my phone as one more remote control for this system, I have not found a need, and I see several reasons why I do not want to do that.

The laptops connected to DACs in each room are generally some I had originally purchased used on ebay.

However, I have a really awesome laptop that weighs about the same as an iPad Pro + keyboard or a Surface, but it is a regular laptop. It has an amazing screen and keyboard and I love using it instead of less capable devices. I can do anything on it, and being able to control my music with it is just an added bonus. If I did not have this laptop, I might use a phone or tablet.

I had people at my house this evening showing them the music setup. They were "amused" that I could be so excited about a text-interface music player running over an ssh connection. They called me "geeky" and I took it as a compliment. But I am still amazed that the "best" solution ended up being so simple. The cmus music player is pretty awesome. It reminds me that GUI’s are not always the ultimate way to interact with a computer.