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