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This app note is a short example of recording multichannel audio on Linux using miniDSP devices.

Please note: miniDSP can't provide support for non-miniDSP hardware and software. In particular, we cannot trouble-shoot Linux-related issues. If you get stuck with Linux and miniDSP hardware, try a simple configuration such as the one we describe here and then proceed from there.

• What you will need
• Linux setup and DAW installation
• Create a project
• Record audio

What you will need [Top]

For multichannel recording, you will need one of the following USB interfaces:

• The USBStreamer (or kit version) supports 8-channel ADAT and 8-channel PCM over I2S (with an additional two channels via TOSLINK).

• The MCHStreamer supports many different formats, including 8-channel ADAT and 8-channel PCM over I2S (optionally with an additional two channels via TOSLINK or SPDIF), PDM and TDM.

• The USB microphone array series (UMA-8/UMA-8SP/UMA-16) support multichannel audio for custom beamforming algorithm development
  
  
• The U-DIO8 supports 8 channels of input and output via AES/EBU or SPDIF (BNC).

 

These devices are all USB Audio class-compliant, so will work on Linux without any driver installation required.

In the case of the MCHStreamer and USBStreamer, the correct firmware must be loaded to configure it for the desired I/O format. For example, for ADAT I/O, load the ADAT firmware. See the relevant user manual for the procedure.

Linux setup and DAW installation [Top]

As a concrete example for this app note, we installed Linux Mint, a user-friendly distribution of Linux, on an Intel NUC. Because of the wide variety of Linux systems, you may need to do things a bit differently depending on the Linux distribution you have installed on your own computer.

For multichannel recording, you will also need a DAW (Digital Audio Workstation) application. For this app note, we installed Ardour. Once the installer is downloaded, open and install it. In Mint, for example, double-click on the downloaded file and then click on the Install Package button.

During the installation process, there were a number of options:

1. We elected to install Jack (although we didn't use it for this app note).
2. We chose to enable realtime scheduling:

Create a project [Top]

First make sure that your miniDSP device is connected to your Linux computer via USB. In the case of the U-DIO8, power it on.

To start Ardour, locate it in the main menu in the Sound & Video section. (Your version of Linux may be different.) When Ardour starts, set the parameters as shown here:

Note that the miniDSP MCHStreamer is automatically detected and can be selected from the dropdown menus for the Input and Output devices.

On the next screen, enter 8 for "Create Tracks," then click OK:

Record audio [Top]

Enable all tracks for recording. This screenshot shows the record enable button for one track:

Then press the main record and play buttons, in that order:

Ardour will record all 8 input channels from the MCHStreamer, USBStreamer, or U-DIO8. Here's our screen after recording an 8-channel file over ADAT with an MCHStreamer:

You can now proceed to mixdown or export to a file. Have fun, and please let us know how you go in our forum!

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The miniDSP U-DIO8 is a compact eight-channel USB to AES-EBU digital interface. In this application note we will show you how to use the U-DIO8 with JRiver Media Center to play back multichannel audio on your Mac.

Please note: miniDSP cannot provide support for third-party software. This app note shows you how to set up the miniDSP U-DIO8 with JRiver Media Center for multichannel audio playback but any functions of JRiver Media Center are beyond the scope of miniDSP support.

• 1. Get connected
• 2. Configure
• 3. Play!

1. Get connected [Top]

You will need a miniDSP U-DIO8 and a multi-channel AES-EBU DAC. Connect the USB cable from your computer to the U-DIO8 and connect the outputs of the U-DIO8 to your DAC, amplification and subwoofers, as shown in this diagram:

2. Configure [Top]

We will assume that you already have an JRiver Media Center library set up, which includes multi-channel audio files. These files can be in multichannel (typically 5.1) PCM format up to 192 kHz, or in multichannel DSD format (again typically 5.1).

From the Player menu, select Playback Options.... Under Audio Device, drop down the selector and choose U-DIO8 Output:

Then click OK.

If you want JRiver to perform bass management, from the Player menu, select DSP Studio:

Configure as follows:

1. Click on Room Correction to enable it and display the control panel.
2. Select each speaker in turn to configure it (as in steps 3 and 4).
3. For each speaker, set the highpass crossover.
4. For each speaker, set the lowpass routing and slope.

You will need to set the items in steps 3 and 4 for your speakers and room. You can also adjust the other parameters on this screen like speaker distance and level.

3. Play! [Top]

Now you can browse to an album or file in the JRiver Media Center library (screenshot at top of page) and play by clicking on the Play button. You will hear multichannel audio playing through your system.

You can check the sample rate of the file and the DAC by going to the Player menu and viewing the Audio Path entry. Here is an example for 5.1 channel FLAC:

When playing multichannel DSD files, JRiver Media Center will automatically convert them to PCM format at 176.4 kHz. Here is an example:

That's it, have fun listening to multichannel audio with your miniDSP U-DIO8 and JRiver Media Center! Let us know how you go on our forum.

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This app note shows you how to stream audio over the network to a miniDSP 2x4 HD, DDRC-24 or Flex by using a Raspberry Pi.

If you're looking for an all-in-one streamer/DSP/digital preamp solution, check out our SHD Series streamers. In addition to the convenience of an all-in-one solution, these models have higher specifications, more digital inputs, digital outputs, and balanced analog I/O (for the SHD model).

Please note: miniDSP doesn't provide support for hardware and software that aren't miniDSP products. This application note demonstrates the use of miniDSP products together with other products.

• What you'll need
• 1. Burn the SD card
• 2. Get connected
• 3. Set up Wi-Fi
• 4. Play music!
• Wrapping Up

What you'll need [Top]

For this app note we will be using the Raspberry Pi Model 3A+. It has only one USB port and supports Wi-Fi only, no Ethernet. We thought it a good fit for this app note. You can use the Model 3B+ or Model 4B instead if you wish, as the instructions are essentially the same.^{*see footnote 1}.

In addition to the Raspberry Pi, you will need a suitable power supply, a micro SD card, and a case. We used the official case as shown in the photos, but there are lots of choices. If you haven't used a Raspberry Pi before, you may prefer to buy a kit containing these extras together with the board.

You will of course need a miniDSP processor that accepts audio over USB. The miniDSP 2x4 HD and DDRC-24 are perfect candidates for a low-cost DSP-powered streamer, as they are compact and very affordable. These two units are the same hardware but the DDRC-24 has Dirac Live room correction built into it. For higher specs and a display, choose miniDSP Flex.

Before you proceed, we suggest that you start the miniDSP Device Console and make sure that you have selected USB audio input. You can also do this with an infrared remote later on.

1. Burn the SD card[Top]

You'll need to download the software that will run on the Raspberry Pi. We'll use the Linux distribution called Volumio for this app note. This is the same base software that we use in our SHD Series streamers. Download it at https://volumio.org/get-started/. Other distributions you could try are Moode Audio and RoPieee (the installation instructions are the same, but you will need to refer to each distro's documentation for the setup process).

Once you have it, burn it to the micro SD card. A good program for this is Etcher, which runs on Mac, Windows, and Linux. Insert the micro SD card into your computer's card slot or a USB card reader. Select the downloaded image and the card, and click "Flash!"

Warning: make absolutely sure that you have selected the SD card and that the size displayed in Etcher matches the size of your card.

Take the card out of the slot or card reader and insert it into the Raspberry Pi. It goes in like this (looking at the bottom of the Raspberry Pi):

2. Get connected [Top]

To connect the Raspberry Pi to your 2x4 HD or DDRC-24, just connect the USB cable from the Type A port on the Raspberry Pi to the mini Type B port on the miniDSP.

Now plug in the power to the Raspberry Pi and your miniDSP. You should see the red light on the Raspberry Pi come on and the green light start blinking. Wait a couple of minutes before proceeding to set up Wi-Fi.

3. Set up Wi-Fi [Top]

Use your computer's network manager to search for a wireless hotspot named Volumio. This is started automatically by Volumio when it can't connect to a network. Connect to this hotspot with the password volumio2:

Then open your web browser at http://volumio.local or http://volumio. Run through the startup procedure and select the miniDSP 2x4 HD or DDRC-24 on the third screen:

Navigate to the Network settings page and locate the Wireless Network Connection section. Select your home network and enter its password, then click Connect. We recommend that you connect Volumio to your home's 5 GHz network if you have one.

After Volumio connects to your home network, the interface will disconnect. Change your computer's network settings back to your home network and reload the Volumio interface. At this point, we recommend that you go back to Volumio's Network page and turn Off the Enable Hotspot setting, as leaving it enabled is a potential security risk.

4. Play music [Top]

For a quick start, go to Browse in the Volumio interface and select Web Radio, then Top 500. Take your pick and play!

Web Radio is not high resolution, but there are a lot of music playback capabilities in Volumio that are. Here are some ideas for you to explore:^{*see footnote 2}

• Go to the My Music page and enter your login details for TIDAL or Qobuz.
• Look at the Plugins page to enable other services like Spotify and Pandora.
• If you have a DLNA music server running on your network, locate it from Browse and then Music Servers.
• If you have music files stored on a network share, add it on the My Music page. ^{*see footnote 3}
• If you are an Apple user, select Volumio as the output device in System Preferences on your Mac or Control Center on an iOS device.

Wrapping up[Top]

That's it for this app note! Have fun, and please let us know how you go in our forum.

Footnotes

1. If you use a Model 3B+ with Ethernet, you may experience some clicks or pops when streaming high-res audio. This is a consequence of the internal design of the Raspberry Pi and is unrelated to the fact that a miniDSP is connected to it. So for the Model 3B+, our recommendation is that you use Wi-Fi. This does not apply to the Model 4B, which has no issue with use of Ethernet together with high speed USB. Note: no such Ethernet problems with our SHD Series streamers!

2. Since the Model 3A+ has only one USB port, you won't be able to plug in a USB stick for music. As shown in the list, however, there are lots of other methods.

3. If you have a large library on a network share, the Pi might slow down a lot when scanning it. For the sake of a number, consider a library of more than 10,000 tracks "large."

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The miniDSP U-DIO8 is a compact eight-channel USB to AES-EBU digital interface. In this application note we will show you how to use the U-DIO8 with Audirvana+ to play back multichannel audio on your Mac.

Please note: miniDSP cannot provide support for third-party software. This app note shows you how to set up the miniDSP U-DIO8 with Audirvana+ for multichannel audio playback but the functions of Audirvana+ are beyond the scope of miniDSP support.

• 1. Get connected
• 2. Configure
• 3. Play!

1. Get connected [Top]

You will need a miniDSP U-DIO8 and a multi-channel AES-EBU DAC. Connect the USB cable from your computer to the U-DIO8 and connect the outputs of the U-DIO8 to your DAC, amplification and subwoofers, as shown in this diagram:

2. Configure [Top]

We will assume that you already have an Audirvana+ library set up, which includes multi-channel audio files. These files can be in multichannel (typically 5.1) PCM format up to 192 kHz, or in multichannel DSD format (again typically 5.1).

In the Audirvana Preferences, select the Audio System tab:

Configure as follows:

1. Click on Change and select U-DIO8 Output from the list.
2. Confirm that the U-DIO8 supports the expected set of sample rates (from 44.1 up to 192 kHz).
3. Ensure that Native DSD Capability is set to None: convert to PCM.
4. The low-level playback options may need to be adjusted depending on your version of Mac OS X.
5. Allocate a good amount of memory for buffering.

(Note that Audirvana does not do bass management. So when playing content without a subwoofer channel (e.g. 5.0), it will be necessary for all speaker channels to be capable of full-range response sufficient for music. Alternatively, if connected to the analog inputs of an A/V receiver, the receiver may be able to perform bass management.)

3. Play! [Top]

Now you can browse to an album or file in the Audirvana+ library (screenshot at top of page) and play it by clicking on the Play button near the top left. You will hear multichannel audio playing through your system.

You can check the sample rate of the file and the DAC in the status area at the top of the window. To the right of the track display is the file format and sample rate, and underneath the play buttons at the left is the sample rate and format being sent to the DAC. For example, for multichannel 5.1 PCM (in FLAC), these two areas are:

When playing multichannel DSD files, Audirvana+ will automatically convert them to PCM format at 176.4 kHz. Here is the display for a 5.0 channel DSD recording:

That's it, have fun listening to multichannel audio with your miniDSP U-DIO8 and Audirvana+! Let us know how you go on our forum.