Raspberry Pi (and similar) as audio player

I figured it was worth separating out discussion of the Raspberry Pi and similar low cost DIY-ish options from the general digital transport thread.

Let's use this thread to discuss the Raspberry Pi, Udoo, Cubox, Beaglebone, Compulab Utilite, Cubietruck, Odroid, and so on. We can also discuss (and possibly help troubleshoot) the various audiophile distros for these devices, such as Volumio and RuneAudio and such.

I got interested in trying the Raspberry Pi 2 as a music player when I saw this thread on HF:
http://www.head-fi.org/t/795895/a-70-bit-perfect-audio-player

And this article on Computer Audiophile:
http://www.computeraudiophile.com/content/638-geek-speak-raspberry-pi-hifi-here/

As well as a few posts in the digital transport thread here:
http://www.superbestaudiofriends.or...olutions-cd-and-sd-players-daps-and-more.212/

The pros of this sort of system added up very quickly:
Low cost
Runs on low power, easy to keep on 24/7
Can be run headless with the right distros
Little to no background noise
Several audiophile distros to choose from
Easy to add SPDIF options (some devices include them on board)

The cons seemed relatively meager:
A little DIY know how needed (easily conquered by some Google searches)
Distros may not be as rock solid as established desktop software
May not sound as good as more expensive sources (debatable)

The clincher for me was that I could give it a try for just over $100, which in audio is pretty much chump change. If I didn't like it better than my Macbook Air, I wouldn't be out much and could repurpose the Pi to use as a video streamer or something similar.

Most of the items I ordered can be found in the Computer Audiophile article:
Raspberry Pi 2
Hifiberry Digi+ board with transformer
Hifiberry Digi+ compatible case
Edimax wifi adapter
Coax cable

Since I have a gazillion micro USB cables and plugs, I didn't order a charger for the Pi, nor did I need a micro SD card as I already had one.

Attaching the Digi+ board to the Pi was incredibly easy, with a 30-pin attachment readily visible. Putting the case together was a snap as well.

I went to Volumio's website and downloaded their RPi2 distro, then installed that to my SD card using Win32 Disk Imager (this process is well detailed in the HF thread I linked to, as well as in the CA article). Once it finished writing, I popped the SD card into the Pi, attached it to my router via ethernet, plugged in the wifi adapter, and turned it on. Right from the get go I was able to use it as headless, although I did have to find send my internet browser to the IP address of the device to get it to connect. From there, I enabled the wifi adapter, connected to my wifi, and loaded the driver for the Hifiberry board.

I powered it down through the web interface (never yank the power cord out without powering it down from the web interface first or you could corrupt the SD card), disconnected the ethernet adapter, and hooked it up to my Bifrost Multibit and to the USB HDD with my music on it through a powered USB 2.0 hub, since the Pi doesn't have enough power to handle a USB HDD without an external power supply (it's fine with USB sticks though).

And here was my first problem. No matter what I did, Volumio staunchly refused to recognize the contents of my USB drive, when it bothered to recognize the drive at all. Searching through Volumio's forums, the only response I saw was to plug the drive in through a powered USB hub, which I had done. So I said screw it and loaded RuneAudio onto the SD card instead of Volumio and went through the setup process again.

RuneAudio worked fine, although it did have one little trick that's worth mentioning: After installing RuneAudio on your SD card, find the "Config.txt" file on the SD card and make the change outlined here: http://www.runeaudio.com/forum/digi-support-in-runeaudio-t2847.html#p10698

This will allow RuneAudio to recognize the Hifiberry board attached to the Pi.

Anyway, once I did that, I was able to set up the system as I did before, and also was able to assign the wifi connection a static IP address, which makes it easier to connect via the web browser in case the "runeaudio.local" doesn't work reliably. RuneAudio feels much more mature than Volumio, which is funny because it's still in beta, but it recognized my USB easily and also gave me more options and a better overall interface than Volumio, so I'm glad I switched to it.

And now the important part: How does it sound? My system is now as follows:

USB Western Digital Passport hard drive connected to powered USB 2.0 hub->Raspberry Pi 2 with i2s Hifiberry Digi+ board->Schiit Bifrost Multibit via coax->Vali 2 with Siemens E288CC NOS tube via PYST RCA cables->Dyanamat modded HD600 headphones with SurfCables balanced cables and balanced to single ended adapter.

Prior to this, my chain was the same except I was using a mid-2013 Macbook Air to feed the Bifrost Multibit via USB, without a Wyrd or Regen.

Using this new setup, which cost a little over $100 for the Pi, board, case, and coax cable, I can tell that the background is much quieter. Pretty darn black all told. This allows me to hear little details that the Macbook obscured, like the needle touching the groove on vinyl rips I have. This setup also has more dimensionality and better instrument separation. It's very easy for me to identify each element within a track now. The Bifrost Multibit is already very good at this, and the SPDIF connection has made that aspect even more pronounced. The low end also feels tighter, so while it had heft before, now it also has more definition.

Overall, I'm very impressed with the performance of the Pi, especially for the price. Who knows, it may be that all of the difference is coming from dumping USB for SPDIF, but this has allowed me to simplify my setup, reduce the system footprint, and the sound is improved. It's a win for me all around.

As I mentioned above, there are several kits like the Raspberry Pi, and some that are prebuilt like the Cubox. I'd be interested to hear if anyone has tried some of the other kits out there for music playback.

 

Thanks - very valuable resource. I think there is a lot to be said for removing USB interconnects from you chain as it seems to be a noisy digital interface. Certainly can't beat the price, I've had failed DIY experiments cost me much more.

One fairly stupid question, did you have to hook this up to a monitor, keyboard and mouse, or is it controlled via a smartphone app or something similar?

 

For Volumio and RuneAudio, you can do it entirely headless through a web interface. It gives you access to all the functions of distro.

 

I have the RPi2 with Volumio. I'm also using a wifi USB adapter. I use a battery to power it, and I have it connected to the Modi Uber2 via USB. For me, it had no trouble recognizing the HDD that's powered with a hub. The Volumio mobile interface is quite nice too (ie. it lets you control your RPi2 using your phone)

 

for those considering the RPI2 route should take a look at this upgrade path for ultimate sound:
https://volumio.org/raspberry-pi-i2s-dac-sounds-so-good/

Checkout what this user did:

https://www.hifiberry.com/2014/05/an-audio-streamer-with-digital-output/

 

I'm not sure why Volumio had an issue recognizing my hard drive. When I googled it looking for solutions, I saw that I wasn't the only one who had that problem. One of the cons of a DIY solution I suppose.

Luckily RuneAudio has a very similar interface to Volumio (I believe it's from a team of designers who broke off from the Volumio team), and it sounds fantastic.

 

Just to be clear, all these add-on boards for audio on the Pi 2 are using i2s, not just the DAC add on boards. You certainly can attach a DAC and even amp directly, but until Schiit starts making multibit add-on boards for the Pi with the megacomboburritofilter, I'll stick with coax.

 

That's the flexibility of the RPi. You can even make your own full fledge xmos based usb dac with balanced XLR: http://www.tjaekel.com/T-DAC/if.html

I will be dying for the day when Schiit makes some kind of (audiophile grade) Rpi based media streamer/all in one unit with the closed form filter.

 

That's impressive! I love how versatile a platform the Pi is.

 

what are the pros and cons of having for example this Raspberry Pi based "headless" system vs using something like Daphile on an old laptop or PC?

 

Biggest advantages are almost negligible power consumption, silent operation, very small physical footprint, and option for potentially better SPDIF output. Plus it's just cool to play with.

 

FYI, Roon is making a custom image for Raspberry Pi use so it can be an ideal endpoint. https://community.roonlabs.com/t/raspberry-pi-support-on-roadmap/1129/54

 

I'd like Roon a lot more if they weren't charging $120 per year for the service. Especially since they've partnered with Tidal, that's $30 per month if you want to take full advantage of what Roon offers.

 

I have very little 24/192 files, partially because I think 24/96 is more than enough, and partially because I don't want to bypass the megacomboburritofilter into my Bifrost Multibit, but I did load some tracks to test on my Pi and have had zero issues with skipping. This goes back to the cons of using a Pi setup, the software isn't going to be as rock solid all the time. Luckily for me, it's been so far so good.

I've had a chance to do some extended listening sessions today and I've been having a real blast. Moving away from USB is a huge relief and running the system headless through my phone is incredibly convenient. Of course, all that's icing on the cake, the cake being the fantastic sound coming out of my system.

 

I haven't yet gotten around to trying linux on it yet, but the kangaroo seems like the logical progression from the Pi in terms of hardware. Really loving mine.

http://www.superbestaudiofriends.org/index.php?threads/in-focus-kangaroo-99-pocket-pc.1338/

 

The Kangaroo does seem like a very nice all in solution, although you would still need a decrapifier or SPDIF converter for USB.

 

Depends on your dac I would imagine. Async usb on the Yggdrasil shows just about the lowest jitter I've ever seen per atomic bob's measurements - no decrapifier required per schiit.

 

What atomic bob shows is a typical standard 1khz test signal only, which does not represent jitter across the entire audio spectrum.

1khz test is good for comparing typical equipment jitter across the entire market in a glance, but is not representative enough to say that Decrapifier won't make a difference.

Subjectively, I notice there's quite abit of bass depth addition when I added Wyrd to the Yggdrasil. This is on speakers

 

http://arstechnica.com/information-...i-fi-and-bluetooth-64-bit-chip-still-just-35/

Ahhh yeeeah, new Raspberry Pi, for the same old price. Built-in wifi and bluetooth, faster processor, 64-bit support, h265 support.

Based on these benchmarks (found in Ars comments), serious serious speed boost.

https://www.element14.com/community...ensive-raspberry-pi-comparison-benchmark-ever