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 [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).
miniDSP USBStreamer   miniDSP U-DIO8

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:
    Enable realtime scheduling for jackd

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:

Project setup in Ardour

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:

Create 8 tracks in Ardour

Record audio [Top]

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

Enable track recording in Ardour

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

Record buttons in Ardour

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:

8-channel recording with miniDSP 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!


Related Products - USB Audio products