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Antipodes Audio

K21 - G4


The Antipodes K21 is the latest evolution of the Antipodes DX. Compared to the DX3, the K21 is faster and more dynamic, at the same time as providing greater detail and refinement. The K21 can be used as a very good Server-Player, running both Server apps and Player apps. It can also be used as a Player only, running just Player apps, teamed with the K41 running the Server apps, for exceptional performance.

The K21 offers an excellent entry point to high-end computer audio, at well below the cost of a K30 or K50, and offers an easy upgrade to the top level by adding a K41 later.

Antipodes Audio’s solution design

Why do I need a high-end music server/player?


The K21, with G4 Oladra technology is the same as the latest K22, but without the Re-clocker, providing world-class and musically expressive sound via network streaming and USB output. Used as both Server and Player, the K21 delivers outstanding value for users with libraries smaller than 8TB, and who do not wish to use DSP features. The K21 can be upgraded later by adding a K41, to reach the same level of performance as the USB output of a K50.


The K21 uses a high-quality single low-powered processing engine that can run both Server applications and Player applications. The K21 can alternatively operate as a world-class Player-only device and is recommended for adding player end-points to an Oladra, K50 or K41, when USB output is preferred. The main signal output is on USB, and is 100% compatible with the USB Audio 2.0 standard, on USB Type A - and the K21 can also stream via Ethernet over your network to streamers.


Vibration treatment is important in any high-end audio system, and any serious system is placed in a well-engineered rack. The same should apply to the equipment cases. They should be just as well engineered to deal with vibration, and we take that very seriously in every Antipodes model.

We also put a lot of design effort into the footers used on the Oladra, and this has trickled down to the benefit of all of the K series models in 2023. The footers include a special polymer that is specifically designed for vibration control, and the very detailed specifications provided by the manufacturer of this material allow us to precisely calculate the thickness to be used in each instance so that the pressure applied to the polymer is always precisely what is required for optimum vibration control performance. In the Oladra and the Performance Series the Polymer is used in a constrained layer damping design that makes it possible to tune each separate footer even more precisely to its optimum pressure, and allow a very small contact area with the equipment rack.


The following Server applications are pre-installed.

  • Squeeze Server 
    - customised version of Logitech Media Server
  • Roon Server 
    - industry-leading user interface and feature-set
  • HQPlayer Server Embedded 
    - industry-leading digital signal processing
  • MinimServer 
    - industry-leading DLNA/UPnP server
  • MiniDLNA 
    - light-weight DLNA/UPnP server
  • SONOS Server 
    - makes your music available to a SONOS network
  • PLEX Server 
    - widely-used and industry-leading a/v media server

Each Server application can play to compatible Streamers on your network. Both Roon Server and PLEX Server can also make your music available to your mobile devices on the move.

You can enable or disable as many as you need with a single click each, and they can play music concurrently. For simplicity, each application is pre-set to play from a common music library. Simply use the Antipodes File Manager application to drag and drop files to the Antipodes music library, and to include any directory on your network in the library. All music in the library becomes automatically available to all Server applications.


The table below summarises the Player(s) that can work with each Server.

Server Application Player Applications
Squeeze Server Squeeze Player
Roon Server Roon Player
Squeeze Player
HQPlayer Server/NAA
HQPlayer Server HQPlayer NAA
MinimServer MPD
SONOS Server No Players
PLEX Server No Players

Note that:

  1. Some solutions work differently, depending on whether the solution is on a single computer or spans two computers (the Server app and the Player app being on different devices), but the Antipodes Management Software (AMS) handles those issues automatically for you.
  2. Roon Server can be used with a range of Players, as shown in the table.
  3. MPD is also capable of playing music from a local library without the need to receive a stream from a server application.
  4. Antipodes music server/streamers do not have a SONOS or PLEX player application. SONOS and PLEX server apps are included for streaming to third-party SONOS or PLEX player devices.


You set the Playback Solution using AMS, which you can open from the Antipodes website, or using the My Antipodes application on your mobile device.

At the solution dashboard, click to display the Preset list (shown above) and click on the Preset solution you wish to use. In the same way, you can switch between Presets with a single click. In the image above, the K50 is currently set to use the Squeeze (Auto) preset and clicking on Roon (Auto), as highlighted, will change the Player application to Roon and the Server application to Roon, and you can then start using the Roon application on your desktop, laptop, tablet or smartphone to play music.



USB Audio 2.0 Output

– PCM to 32 bit/768kHz
– DoP to DSD256
– Native DSD to DSD512

User installable storage

1Bay SSD Slide-In (Up to 8TB)

Hardware Modules

Computing Engine (Player) - V6X






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