JustBoom frequently asked questions

My Raspbian based OS does not work on my JustBoom

The best approach with this problem is to upgrade the OS to the latest kernel.

To upgrade your system use the following commands from a shell terminal:

sudo apt-get update


sudo apt-get dist-upgrade

Restart the OS and your JustBoom card should be available for you to select.

Note: The problem behind this is that only very recent versions of the kernel support our boards  and upgrading is by far the easiest way of fixing the issue.

My JustBoom isn’t recognised by the OS I am using

Some OS will not configure the JustBoom cards without some additional configuration.

Generally it will be a question of adding two lines to the config.txt under either /boot or /flash

  • For DAC and Amp cards:
  • For Digi cards:

save, reboot and you should be able to select your JustBoom card within your distro preferences.

Note that if there already is a line dtparam=audio=on you should comment it out with a # at the beginning.

My JustBoom Zero board is not playing despite all the software being properly configured

The JustBoom Zero boards can be used with stacking headers or installed directly on the Raspberry Pi Zero. Some stacking headers and some 2x20 male headers on the market though are too thin or too short to provide good contact with the board.

If you are using stacking headers make sure that the pins are squared and are at least 0.6mm in width. If you are soldering the 2x20 male header on the Raspberry Pi Zero make sure that the pins are 0.6mm in width and 6mm in usable height.


You can find some headers at Pi Supply and good stacking headers at Toby.

Which are the Inputs and which the Outputs on Amp and DAC?

The Inputs and Outputs of the JustBoom DAC and the JustBoom Amp are clearly highlighted in the picture. Please bare in mind that should you combine the two together you can always used the micro USB power input unless you are connecting passive speakers to the Amp. In this case refer to this document which clarifies the specs of the power supply to be used depending on which speakers will you use.

Note: The Input on the Amp is intended to be a Line In type of signal and it is only available when the Amp is used on its own. Do not use this screw terminal when the Amp is stacked on top of the DAC or the DAC HAT.

Note: The polarity of the screw terminal block for the Output on the Amp is also reported in the picture.

What PSU do you recommend for the JustBoom Amps?

We will be listing a few PSU choices on our online shop fairly soon but in the meantime you can choose from this selection:

What are the sampling frequencies and the bit depth supported by the JustBoom cards?

CardSampling Frequency (KHz)Bit depth
Justboom DAC 28-108 16,24
Justboom Amp HAT 8-192 16,20,24,32
Justboom DAC HAT 8-384 16,20,24,32
Justboom Digi HAT 32-192 16,20,24
Justboom Amp Zero 8-192 16,20,24,32
Justboom DAC Zero 8-384 16,20,24,32
Justboom Digi Zero 32-192 16,20,24

Please bare in mind that some OSs will not allow 24 bit decoding. The majority of today's Linux Kernels are configured for 16 bit and 32 bit only.

How do I add a header on the DAC HAT so that I can still use the standalone Amp?

The JustBoom DAC HAT comes with the possibility to install a header to replicate the GPIO of the Raspberry Pi. The header can be installed on P2 and can be installed in a standard fashion with it being soldered on the bottom side of the board with the pins made available from the top.

This approach although valid will preclude the installation of the optional standalone Amp. In order to solve this you can install a right angled header by soldering it from the top of the board and with the pins sandwiched between the Raspberry Pi and the JustBoom PCB as shown in the picture.

Routing the GPIO pins in this way can be confusing as the pin numbering is somewhat reversed from one might expect at first glance. We have added a pinout to this picture to help you work out which pin is which.

Note: This configuration can be helpful even when installing a rotary encoder. The pinout reports the default setup of our rotary encoder script.

How many JustBoom products are there?

There are 8 JustBoom products. Read more about them by clicking on the product links below.

What could I use JustBoom products for?

  • Multi-room streaming/local audio player
  • Interactive art projects with audio requirement
  • Arcade table projects with high quality, immersive audio
  • Refit old radios and boomboxes (Roberts radios etc) with high quality streaming audio
  • High quality headphone amplifier for your digital audio receiver
  • Streaming (either from cloud or network storage) high-definition audio player
  • Media centre / set-top box living room entertainment system
  • Shop floor / elevator / background music audio player
  • High quality audio player with local storage

What are the features and benefits of the JustBoom HATs?

  • Full driver support in Raspbian / NOOBS
  • Compatible with OSMC / RuneAudio / Volumio / Moode / PiCorePlayer / PiMusicBox / OpenELEC and others
  • Mounting hardware included
  • Full high quality audio - up to 384kHz/32 bit
  • Plug and play compatibility for ease of use
  • No soldering required
  • Compatible with Raspberry Pi  A+,B+, 2B and the new 3B
  • Powered by the Raspberry Pi GPIO header
  • Hardware and software volume control from your Raspberry Pi
  • Fully HAT compliant
  • All Raspberry Pi GPIO pins still accessible via 40pin unpopulated extension header

What are the features and benefits of the JustBoom Standalone Boards?

  • Full high quality audio - up to 192kHz/32 bit
  • Mounting hardware included
  • Plug and play
  • No soldering required
  • Compatible with Raspberry Pi  A+,B+, 2B and the new 3B
  • Compatible with the JustBoom DAC and DAC HAT or alternatively use as a standalone device
  • Onboard, hardware jumpers for configuring output voltage and gain settings (jumpers could optionally be changed with switches)

Where can I buy JustBoom products?

At the moment, we're currently selling the JustBoom product range with these distributors.

I would like to stock JustBoom products. How can I do this?

Thank you for the interest! If you'd like to become a reseller, please email us at support@justboom.co