[mfsoa]

With Tommy's permission I'd like to document my experience using a Rapsberry Pi as a music renderer.

A few basic rules:

1) I am not an expert on this!  I do not know linux from a lorax, which should offer encouragement to others who may be daunted by using a linux-based solution. I would very much welcome the input (and corrections) of others more experienced than I. I have read a bunch and have used the Pi for a few months, so that's my level of expertise.
2) My Pi experience is limited to one particular set-up. There are tons of things you can do with the Pi and I won't get into that so much. I'll define my setup below.
3) Some of the info I'll provide may be very basic and of no use to most people, so sorry if it seems like I'm stating the obvious. I have no way to know what my target audience is!
4) I'm sure I'll miss mentioning some pros and conds - I don't intend to slant things one way or another if thats what it looks like I'm doing.

My Pi is being used as a Squeezebox emulator. It runs a program called piCorePlayer (pCP (unfortunate acronym)). Running this program on the Pi basically turns your Pi into a Squeezebox. Therefore if your Duet or Touch etc. is in need of replacement or sibling(s), pCP on a Pi will add one more SBox to your arsenal.

My setup: I have an external USB drive attached to my main (Windows) PC. The PC runs Logitech Media Server (LMS), which is required to use pCP. The PC is wired to my home network via ethernet. The pI is also wired to my home network via ethernet. (It is possible to add wireless capability to the Pi but I have not done so - There are many posts on forums regarding getting wireless to work -I'd suggest finding out which wireless adapters are known to work and try one of those). The Pi is then connected via USB, spdif toslink or spdif coax to my dac (Marantz SA8005). I do not have a touch-screen for the Pi but IIRC there is an official one (7" ?) available for the Pi.

The Pi itself the latest model available, a Pi 2 Model B. It has a 900 MHz quad-core ARM Cortex-A7 CPU and 1GB of ram. It needs a 5V power supply. It's possible to run w/ a standard phone supply (I'm pretty sure) but I bought a 2.5 amp unit (CanaKit) in case I need some extra oomph. Some report that the Pi can run out of power via its USB ports, and therefore they use a powered USB hub. I don't have any extra bits powered from Pi's USB (like a USB drive, keyboard or mouse). It is possible to double the available current available from the Pi's USB ports - pCP already has this feature enabled for you. (IIRC from 600 mA to 1.2A total current from the 4 USB ports). My Pi is powered with the Jorome linear supply I used to use for my Touch, by using a barrel-to-miniUSB adapter.

Why LMS and pCP? I have been using LMS for a long time, and have 5 various Squeezebox devices already in use around the house. Therefore I am familiar w/ the LMS environment and using the Pi is just like using one more SBox. Did I need the Pi? No, but I wanted to play. It currently replaces a Touch in my main system. Do you need to have a swarm of SBoxen already in order to use a Pi? No - many users download and use LMS (free) only to use w/ Pis.

More to come...

[mfsoa]

More on the Pi hardware:
My Pi has 4 USB ports, an ethernet port, an analog mini-headphone jack (some say it doesn't sound very good and I'd have to agree - noisy, but good for confirming basic functionality) and an HDMI port. I have never used the HDMI so can't say much about that.

So the basic board gets you USB outputs. If you need to add spdif toslink or coax, you buy an additional board, known as a HAT (Hardware Attached on Top). The HAT I have is a Digi+ made by HifiBerry. It sits right on top of the Pi board (pops right on - no soldering) and connects to the Pi's I2S output and takes its power from the Pi. From what I read the Digi+ has its own clock and has lower jitter than the Pi. Therefore it is important to get the correct case for your Pi - If you add the Digi+ you need a bigger case. The Dig+ is available w/ either a transformer coupled or a non-xformer coupled coax out. I chose the transformer coupled because it cost more and therefore has higher audiophile snob appeal. Seriously, the xformer coupled is supposed to be the higher quality output but who knows?

My Marantz SA8005 has toslink, spdif and USB inputs. I bought the Digi+ more for experimental purposes and will most likely just use the USB. Each user must decide what output works best for their situation. I will most likely but a second Pi w/out the Digi+ and use it in my main system, and move my Digi+-equipped  Pi to another system that lacks USB input.

There are other HATs of course - I2S dacs, power amps etc - I have no experience with those.

Some say that a drawback to the Pi is that the ethernet and USB share then same bus. I have not experienced any issues I can pinpoint to that. From what I read it looks like the newest Pi is a significant step up in performance from the older model and many of the older unit's issues have been eliminated.

So what's it cost? Very roughly - $35 for the Pi, $45 for the Digi+, $10 for the 2.5A power supply and ~ $15 for the case. I also needed a micro-USB card a card reader, like $20. I got it all from Amazon - maybe could have saved a few $ by shopping around.

[mfsoa]

More on the software:
piCorePlayer (pCP), to me, seems like a great piece of software. It installs and runs a program called Squeezelite. I had never loaded an image onto a Pi before and had no trouble at all doing this.

Basically, download pCP, burn the file onto the micro SD card using Win32diskimager, pop the card into the Pi, connect the Pi to ethernet and insert its power cord. In about 15 seconds the software is loaded onto the Pi and you set up to play via the headphone jack. The Pi shows up in LMS as another one of your SBoxes. Simply choose and use that player just like any other SBox. One advantage touted for pCP is that the program runs entirely in the Pi's memory and not off the card. Therefore power interruptions can't wreck your card, as I have read happen.

Within pCP there are tons of things to configure. The most critical is to tell it what output devise you are using. You can only use one output device at a time, for example the USB and the Digi+ can't operate simultaneously. Once the correct output device is selected you can really start fiddlin-

pCP offers you almost unlimited ability to upsample and change the filter setting of its output. I won't cover much about filtering etc. because I don't know the math behind it. Tons of info on the web about that already. In my case, my dac can take up to a 192K input. Through a short string of commands entered into the appropriate pCP fields (you do not have to connect to the Pi via Putty and do linux programming) I tell it to
1) upsample everything to the maximum integer multiple less than or equal to 192000 hz, to
2)apply an intermediate phase filter (linear = no pre-ringing, all post-ringing, intermediate = some pre-ringing but more post-ringing, and linear = equal amounts of pre- and post-ringing. Additionally, these filters are associated w/ numbers, minimum phase = 0 and linear = 50; you can choose any value in between to really tailor the sound). and
3) Apply a slightly lower filter slope.
4) Use 28 bit internal processing
The command to do all this is "mI:::28" (thanks to John Swenson for this recipe (yes that's what it's called)). I agree with him that this is a great sounding combo. I am far far from understanding or exploring all of the available options for tailoring the SQ to your particular tastes, but after having this ability I do not want to go back to a situation where I have to accept the single chose my dac or cd player mfgr chose for me. Want to rich, luxurious sound of a minimum phase dac? No problem. Want to ultra-precise sound of a linear phase dac? Go for it. It takes about 20 seconds to make the change in pCP and be playing tunes again.

[mfsoa]

How's it sound?

I think the Pi is a distinct step up from the Touch it replaced. The coax seems a bit better that the toslink - a little better defined although one may prefer the ease and smoothness of the toslink.

I think the USB is a slight step better than the coax, although I hear this can be highly dependent on the particular dac. The number of possibilities are staggering though, between output device, upsampling rate, filter setting, filter slope setting etc.

On my dac, the USB allows for 2X DSD via USB. While I have only a small number of DSD and 2X DSD files they play perfectly via the Pi. I just need to put a "-D" into one of the pCP fields. I have no problems playing 24/192 via toslink, coax or USB.

The Future?
There are many other software choices for the Pi - I see Volumio and Moode mentioned frequently. Moode has a really slick user interface and Volumio seems popular, but AFAIK they work best w/ media attached directly to the Pi  which is not how my system is set up (could be wrong about this).

The big daddy software seems to be HQPlayer. This performs all difficult upsampling/filtering/DSD-conversion on the PC and then, using a mode called NAA (Network Attached Appliance I think) sends the info via ethernet to the Pi. This is supposed to sound great but I haven't tried it yet.

There is also the offering from Max2Play - With this you can run LMS and Squeezelite on the same Pi, w/ your USB drive attached directly to the Pi for an all-in one super-compact system. Tried it briefly but wanted to stick to my normal LMS configuration.

Is the Pi as good as other renderers? Does it have the feature set you need? I can't answer that for you.


Hopefully this rant will encourage the interested to take the plunge. Heck it's like $50 and so damn cute.

If I can be of any help or got anything horribly wrong, please let me know.

An interesting link on using the Pi:

https://parttimeaudiophile.com/2015/05/23/review-raspberry-pi-2-as-music-streamer/

Enjoy,

-Mike

[gregcss]

I experimented with RPi as a squeezebox player and found it to be quite good for the price - seriously I dont think it gets any cheaper than this. I did not get the Digi+ to try digital coax out so I only used USB out from the RPi board to my Emotiva XMC-1. I thought it was at least as good (maybe better) than my squeezebox touch with Touch Toolbox 3.0. As a last test I did a factory reset on the SBT and installed Enhanced Digital Output and compared to the RPi. With this configuration I thought the SBT was better..and should be given the cost of the player, Bolder digital mod, and Paul Hynes power supply. In any case I think the RPi is a terrific value.

[jseipp]

I just quickly want to say a big thank you for generously posting your experience in such detail!!

You've given me the courage to dive in -- I'll let you all know how that goes when I get that far.

[AmpDesigner333]

Mike,

Thanks so much for starting this thread and putting lots of great info here!

-Tommy