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How to Network your Mac music system with the Raspberry Pi and HiFiBerry – Part 2

In this, the second in this series of articles, I’m going to show you how to set up networked playback with your PiStreamer. (If you haven’t already, please read Part 1 to set up a Raspberry Pi with HifiBerry DIGI+ card first, as this article won’t make much sense otherwise. Part 3 will cover some additional topics.)

Networked music playback can be a bit… confusing. It’s not all that hard to do, but there are so many options and things that only partly work, that it can be a frustrating time if you start completely from scratch. I’m going to assume that you already have:

1. A “PiStreamer” box, already set up as described in Part 1. (Please note: As of March 2016, the third-generation Raspberry Pi 3 still has “teething” issues. I recommend sticking to the Raspberry Pi 2 as described in Part 1.)
2. An iTunes library running on a Mac.
3. An iPad or laptop that you can use to control playback.

If this is your first time through this article, I suggest reading it all the way through. If you’ve come back to look for a specific section, here are the quick-links:

• System architecture
• The renderer
• The server
• The control point
• Playing music
• Going high-res
• USB DACs
• Concluding remarks
• Appendix A: Starting MinimServer automatically
• Appendix B: Enabling volume control

System architecture

The system architecture we are going to use in this article looks like this (there are other ways to do it, but I think this is the most straightforward):

At the right is the renderer – this is the thing that actually plays audio. In our case, that is the PiStreamer running the volumio software, set up as described in Part 1 of this series. (If you haven’t already read that article, please jump there first, as the rest of this article won’t make any sense otherwise.)

At the left side is the server, which indexes the music files and sends them on command to the renderer. In this article, I am going to use a free program called MinimServer, which you can download and install on your Mac. (You can run it on other things too.) Most likely, you will run it on something like a Mac mini, which you can leave on all the time.

Finally, at the top is the control point, which is the user interface that controls music selection and playback. It sends commands to the server and renderer to make music playback actually happen. In this article, I will use a free program called Kinsky, which you can download and run on either a Mac or an iPad.

The following sections will show you how to set up each of these.

The renderer

As mentioned above, you will already have the renderer from Part 1. We need to make a small configuration change. Go to the Volumio web interface (either enter “volumio.local” into the URL bar of your browser, or click on the bookmark that you set up in Part 1 as suggested). Drop down the main menu (top right) and go to the System page. There, enable these services:

Then click “Apply.”

The server

I’m assuming you already have an iTunes library on a Mac. It’s probably best if it’s a machine like a Mac mini that you can leave on all the time. However, it could also be your laptop – it doesn’t really matter, as long as it’s turned on while you play music.

I’m not going to use Apple’s iTunes sharing. Instead, your existing iTunes library will just be used as music file storage, and a different piece of software called MinimServer will deliver (“serve”) those files over the network. Follow these steps:

1. Go to the download page for minimserver and download the MinimServer install file for Mac OS X. (You don’t need the MinimWatch file.)
2. Double-click to open the downloaded .dmg file.
3. Drag the MinimServer application to your Applications folder.
4. Navigate to your Applications folder, control-click on the MinimServer application, and select “Open” from the menu. At the next dialog asking you if you are sure you want to open it, say “Yes.”
5. If you get stuck with any of the above, please see the MinimServer OS X installation page.

If that all went well, you should see a little note icon in the menu bar. (The note with an open circle is called a minim, by the way. It represents a note two beats long.) Pop down the MinimServer menu:

Select “Properties.” The only configuration that should be needed is to add an entry to the contentDir property. Here I’ve added my iTunes library:

(You should be able to simply type the same thing in but substitute your username for mine. If you have located your iTunes library somewhere other than the default location, such as on an external drive, you will need to enter the correct path to it.)

The control point

The control point is the user interface that sends commands to the server and renderer to make control playback. I suggest starting with Linn Kinsky (which is free). You can install Linn Kinsky on your iPad from the App Store, or download Kinsky from here and install it on your laptop.

Start Kinsky on either your iPad or laptop. (The screenshots that follow are from the Mac version, because it’s easier to take screenshots, but the iOS version is almost the same.) Here’s the start screen:

From here, we need to select the library and navigate it. Double click on “Library” at the top left, to see:

In my house, there are actually two uPNP servers running. We might look at the Synology one later, but for now, double-click on “MinimServer[fire]” (where in your case, “fire” will be the name of the computer that you are running MinimServer on). You will get to the top level of the library, which provides any number of ways of navigating the library:

I find it easiest to just navigate by album, so if you double-click on that, you can then scroll through the library by album:

(I’ll admit that the Kinsky interface isn’t the zippiest once the library grows a bit, but I find it’s good enough. See Part 3 for some alternatives. In the example, you can see that there are some albums displayed without artwork – this is different from iTunes and I haven’t had a chance to really look into it yet.)

Play music

Now you need to set the destination for music playback. Pop down the “Select room” menu and select Volumio from the list:

(You might be surprised – as I was initially – to find several devices listed here. Things like TVs and AVRs might appear here.)

The final setting is the menu at the top right, which in all screenshots up to now was labeled “Select source”. After selecting volumio just above, however, it will have changed to “volumio”. Confusing, I know, but if you drop it down, you will see that there are two options, one called “PlayList” and one called “volumio”. Select the “PlayList” option (I find this works better):

OK, it’s time to play some music (finally)! Right-click on an album in the album list, and select the “Play now” option. The playlist on the right will update to show the list of tracks now in the playlist:

And… you should hear music coming out from your speakers! (Or headphones, or whatever you have connected to the output from the Raspberry Pi.) You can check the Volumio web interface to see that the tracks have been queued for uPnP playback:

And that’s it! You don’t need to do anything more. If you want to investigate, there are ways to change the way that MinimServer indexes and displays your music library to uPnP control points. You may also find that the interface is not as powerful as the music player that you are used to – for example, lack of or limited search, slower scrolling, and so on. I’d agree… but, on the other hand, you don’t have to be anywhere near a computer to do this, and you can send music to any PiStreamer anywhere in the house, and…..

Going high-res

iTunes is not able to handle high-resolution files very well. There are various workarounds, but I never really spent a lot of time figuring it out. Fortunately, with this setup, it’s very simple to add high-resolution albums to your PiStreamer playback. First, create a folder somewhere to store your high-res files. (You may already have some high-res files in a folder, in which case you can use that. Otherwise, create the folder and put some 44.1 kHz albums into it for testing.)

Drop down the MinimServer menu and go to its Properties again. At the right of contentDir, click on “+” and enter the path to the folder containing the high-res files. Here’s mine (the high-res files are on an external drive, hence the name starting with “/Volumes/”):

Click OK, then pop down the MinimServer menu again and (just to be sure) select “Rescan.” Go back to Kinsky and you should see the high-res albums in the album list, mixed in with the albums from your iTunes library.

How well does high-res playback with the PiStreamer work? Great! With the HifiBerry DIGI+, 192 kHz is no problem. With a sufficiently-capable USB DAC and a wired network connection to the Raspberry Pi, I was able to play DxD (352 kHz).

What about DSD? Well, for DSD playback to work, all three of the components in the system architecture diagram above need to “understand” DSD. In our setup, MinimServer (the server) and volumio (the renderer) do, but Kinsky (the controller) does not. So, DSD playback doesn’t work with the setup just described. However, with a different controller, it can work. In the next article in the series I will describe the use of BubbleUPnP for Android, which will enable DSD. (Note: for DSD playback, the DAC must be connected via USB.)

USB DACs

I suggested in Part 1 that you start with the SPDIF connection from the HifiBerry DIGI+ board to your DAC. I have found the SPDIF output to be more reliable than a USB connection. It’s not that USB doesn’t work, it’s just that with some DACs the USB hasn’t worked as well. (I really don’t know why.) Once you have the PiStreamer working, try a USB connection if your DAC has one – just connect a USB cable from one of the RaspBerry Pi’s USB ports to the DAC’s USB input.

In the Volumio web interface, go to the Playback menu. Drop down the menu next to “Audio output” and you should see your USB DAC listed there:

(In this example, the USB DAC identifies as “G1V2”.) Select your USB DAC, then click “Save Changes.” Wait a full minute, and then try playing audio again.

Concluding remarks

That’s it for this instalment! If you’ve followed through the steps above (and in Part 1), you now have a functioning networked Mac music system.

In Part 3, I’ll cover some miscellaneous topics, including more controllers, Airplay, WiFi, and using an Android tablet.

Appendix A: Automatically starting MinimServer

If the computer that you installed MinimServer on is a dedicated music computer, you may wish to have MinimServer automatically start up when it boots. (Note: I do not recommend this for a computer that has important files on it, and a laptop in particular, as it requires that you auto-login, which is very poor security. For a music server with nothing much critical on it, it doesn’t matter.)

First, enable auto-login. Go to System Preferences, then Users & Groups. Click on “Login Options” and select your account near the top:

Next, select MinimServer to start automatically. Click on your username at the left and select the Login Items tab. Down near the bottom, click on the “+” icon and select MinimServer from the Applications folder. It will appear in the lst at the right. Click on the checkbox to enable it for auto-startup:

I have read that sometimes there can be an issue with MinimServer not finding the music files when it starts (which could happen if you had the files on a network drive, for example). I didn’t have any issues with this, but if you do, go to the MinimServer Properties and on the Advanced tab, set a startup delay:

Appendix B: Enabling volume control

In Part 1, I recommended disabling volume control. This makes sense if the PiStreamer is connected into a system with a separate volume control. However, if not, you will want to enable volume control. Open the Volumio web interface and go to the Playback screen. Scroll down to “Volume control mixer,” select “Software,” and click “Save Changes.”

In Kinsky, you will see that the volume control widget is now enabled (on the right here, set to 57):

Acknowledgments

The author gratefully acknowledges the support of the following companies and individuals:

• HifiBerry, for providing the Raspberry Pi add-on board (DIGI+) and case used in this article.
• Patrick Dillon, for reviewing and commenting on the article prior to publication.