Sound Devices A20-Nexus, Monarch Antennas, A20-Mini Transmitters
Sound Devices A20-Nexus, Monarch Antennas, A20-Mini Transmitters
Sound Devices A20-Nexus Multi-channel Digital Receiver
Sound Devices A20-Nexus Multi-channel Digital Receiver
Sound Devices A20-Nexus Front & Back Panels
Sound Devices A20-Nexus Front & Back Panels
Powering the Sound Devices A20-Mini Transmitter
Powering the Sound Devices A20-Mini Transmitter

The A20-Nexus looks both robust and very elegant from the get-go!

The housing itself is quite discreet (1.6” thick, 8” wide) and the materials seem solid. Weighing in at just over 2.8 lbs, it is much lighter and less clunky than an Octopack with 4 receivers, whose weight is about 4.4 lbs.

The front is very streamlined

- Two BNC connectors for antennas (with the option in the menus to choose to activate one side or both, whether in active or passive mode).
- A 1.8” headphone mini-jack.
- A rotary knob familiar to regular Sound Devices users for, in particular, adjusting the headphone level and browsing dropdown menus before selecting by pressing.
- A fairly discreet orange button for turning the machine on and off, and for accessing the main Nexus menu.
- And to top it off, 4 OLED touchscreens! These offer very clear displays of the various receiver units, allowing users to quickly perform operations on one of them.

A wide range of connectors on the back

- Two BNC connectors for antennas: it is not possible to use the two back and front pairs at the same time, which is unfortunate as that would have enabled coverage of two distinct areas as, for example, with the Wisycom MRK16. Instead, you have to pick in the Nexus menu which pair you want to use depending, for example, on whether Nexus is in a soundbag or not.
- Two Sub-D 25s for each of the 8 analog (mike or line level) or digital (AES) outputs.
- Two RJ45 ports that can be used to transmit all available audio signals with the Dante protocol and to control commands.
- A SFP port for setting up a Dante network + Control with an optical link.
- A BNC input for LTC or Worldclock synchronization.
- Two SMA ports for the two omnidirectional antennas required by the NexLink network (2.4 Ghz).
- Two TA4-M power inputs (a feature since series 8 of Sound Devices) and two HRS 4-point output.
- Two USB ports: one USB-A for several functions such as pairing the A20-Mini with the Nexus using the Nexlink protocol the first time, synchronising Timecode of a A20-Mini, connecting a keyboard, etc… and one USB-C (for factory settings).

Obviously, the decision to put all of these connectors on the back of the device was a natural one, but it has to be said that it does not make it easier to fit in a soundbag.

Using the Nexus

When turned on, the displays give a lovely demonstration of their clarity and, once you are in the menus, everything is highly contrasted and colourful, making everything very precise and user-friendly. The touchscreen feature is nice and responsive, though it may not suit large fingers – but that is fine, because the rotary knob can be used for more precise operations.

The NexLink

This tool involves creating a 2.4 GHz duplex communication network between the Nexus and the A20-Mini and turns out to be essential (since the A20-Mini have no displays) and well matched to the “A20-Remote” application for making all the settings adjustments you wish to make on the transmitters. The range is not exceptional but is adequate for interacting with the transmitters before they are fitted on the talents (the quality of the NexLink network reception can be displayed on each transmitter). After that you're better off using the application.


The scan function (which, happily, is much easier to read than on the A10-RX receiver) has been rather well designed and proves to be very useful, as it has a real-time display of the spectrum across the whole A20-Nexus large bandwidth from 470 to 1525 MHz. This is spread across 3 displays and allows for a more accurate scan of the desired band (the one on which your transmitters work).

Another highlight: after running a scan, you can decide to send through the NexLink network the frequency that can be used on each transmitter.

The various transmitters

As the A20-Nexus is designed to work with the A20 series, the combination of the two performs very well, especially thanks to the NexLink network. But it is still eminently possible to connect an A10-TX transmitter to the Nexus, although that loses some of what makes it so good, as without NexLink all of the settings have to be done manually just like with traditional transmitter/receiver combo. The Nexus is not compatible with other brands of digital transmitters.

It's hard to avoid pointing out the significant down side to the A20-Mini: its battery life. The transmitter's shape (the same as for the Mini TX40, like a bar of soap, and which also did not have a screen, forcing users to adjust the settings with the small remote control) and weight are very attractive! Sadly, unlike with its competitors (both digital and with Li-Ion batteries) such as the Shure ADX1M (9 hours battery life, according to manufacturer's data) and the runaway leader for battery life, the Sennheiser SK 6212 (12 hours!), the A20-Mini doesn't make the grade, offering just 4.5 hours. So it is almost essential to use it with its battery doubler in order to reach the level of the Shure, which reduces the A20-Mini's mininess ... and generates above-average heat.

All the same, its range is good, and it offers great terrific sound quality, is easy to use and can do 32-bit recording on its internal 64 GB memory (which can be controlled through the application and NexLink).

To conclude

Sound Devices has hit the mark with its A20-Nexus, which successfully meets the growing and contradictory demands for compactness and no compromise on capacity: as a result, you can, depending on the option chosen, get 8, 12 or even 16 channels in a unit that is smaller than the usual RF multicouplers. We combined the A20-Nexus with a Cantar X3 recorder using the Dante protocol but it goes without saying that associating the Nexus with a Sound Devices unit such as the Scorpio lowers even further the already tenuous border between the Recorder/RF Unit combination and gives the option of controlling even more settings directly from the recorder (the GainForward function, to name but one, the Scorpio's gain control works directly on the transmitter's input level).

Maybe we will soon see recorders on the market with a RF receiver unit directly built-in ... but that would inevitably raise a legitimate question about resilience in the case of a breakdown, a question that is already critical with the Nexus. If the Nexus were out of order, there would be no more radio mike on the set! So, it is worth covering yourself by having at least one extra A20-RX (if not A10-RX) receiver.

It is worth pointing out that with the A20 series, the Audio Limited brand permanently disappears from the pro audio world.
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