A couple of weeks ago I added the Pi2AES HAT to the Raspberry Pi, and I’ve been really impressed. I do think the Matrix cleans up the USB signal, so I would guess the difference would be more dramatic if I was going direct from USB to the DAC. But very happy with the sound, and I like how I can use the I2S output to the Topping D70 DAC (and make use the Pangea I2S cable I bought months ago, which never worked from the Matrix to the D70).
The Pi2AES HAT is limited to a 192k PCM sample rate, so no DSD. But for my listening and my system, that’s totally fine.
At which point, using the various web pages, you can configure it to be
a player (with an instance of Logitech Media Server running elsewhere on the same network)
an instance of LMS and a player in one
just an instance of LMS.
I have used the player with a USB DAC (Behringer UCA202, which has optical out too), and with a HiFiBerry Digi Pro Plus (which only has spdif rca and optical out, no analogue) the HiFiBerry range also has DAC hats etc.
Note that the “HAT” boards connect to I2C on the Pi board, so are effectively I2S to SPDIF or I2S to analogue DACs.
A USB DAC, however has to compete with pretty much everything else on the USB bus so may not give as good results (the uca202 worked fine for me at 48kHz sample rate).
That USB bus speed concern diminishes considerable with the newest Ras Pi 4 though as it has a USB 3 as well as a USB 2 bus.
All my experiments (and finished items) have used Ras Pi 3B plus, I intend to get a Pi 4 or two soon though to play with
Once set up in terms of booting etc. you can then, to create an LMS server, load LMS onto it, and once that is running, it’s control web page is available on the same browser adress for your Pi but on port 9000.
e.g. you might type http://192.168.1.27:9000.
That gets you to the LMS control panel, skip signing in to “MyLogitech” or “mysqueezebox” or whatever it is, and go straight to the LMS panel.
Once there there is a link to “settings” at bottom right.
This opens another web page, where amongst other things you can configure plugins.
You can enable or disable any of the “official” ones, including BBC SOunds, Bandcamp, Amazon Music, qobuz etc.
The inevitable reboot later, once connected to the LMS control web page again, you can then use the settings page to sign in to BBC, Bandcamp, or whatever (Bandcamp requires some fiddling about with browser tools to extract a session cookie, but BBC sounds is a simple username/password.
More to follow as it comes to me…
(meantime, and I know this description is fairly vague, happy to answer specific questions if anyone is having a go at this e.g. to build an all in one “BBC Sounds / Bandcamp streamer” solution).
Hardware more thoughts - the e.g. Behringer UCA202 is a very cheap USB DAC / optical pass through, costs about 30 quid, and is limited to 48 kHz, but then so is BBC Sounds, Bandcamp et al so for a box for these that is fine.
The HATs go up to 96 or 192 kHz, some with separate clock chips etc. so obviously better for all your local HD files.
SqueezeLite software can also handle resampling (down and up, at least as far as 768 kHz via USB out) and a range of digital reconstruction filtering to go with that which can also be interesting.
I’ve also seen good reports (on here) for the PI2AES add on DAC (which has balanced, and I think I2S also).
I’d be very interested to her from anyone using (successfully) a Pi via USB driving a DS DAC (not that I am getting a DS DAC but it would be useful to know and collect that info in this post).
*** Using Squeezlite to resample up and adjust filtering options etc. ***
Worth adding that LMS / SqueezeLite does sync’d multi room, and runs an apple-compatible “Airplay” type server on the LMS server instance, which can also be sent to one or multiple players.
A handful of Ras Pis and (can be) cheap DACs / speakers gives a very powerful setup, with not too much faffing and IT-arm-waving, but can also drive high end DACs and sound most excellent with a bit of care and choice of components, all driven by iPeng or Squeezer (and a web browser for configuring the server and players)
p.s. no I’m not competitive with PSA’s highly engineered Octave system, I wish 'em the best of luck with it, I bet it looks (and probably sounds) great without any IT arm-waving!
Where it (or Roon?) would beat LMS etc. is MetaData - LMS relies on embedded tags (in FLACs, AIFFs, or even MP3s. The others aim to pull in lots of “rich” extra data about the stored or streamed music. I’m happy without it though - I use iPeng on an iThing, and use Wikipedia on the same iThing, works for me…
one pi - running picoreplayer, squeezelite disabled, LMS installed and running.
music library mounted from a NAS elsewhere in the house. (all configurable from a web page).
5 port switch connects to the Pi next to it, the pi player on the hifi (next pic) and the rest of the house.
second pi running picoreplayer with squeezelite enabled. java lite installed and running, connects to the switch in the previous pic. power, analogue video out (4th “pin” on the 3.5mm jack on the pi).
audio out via TOSLINK from the hat, custom case (steel) for the pi and hat combo (made by the same people who make the hat i think)