A20-Nexus

8-, 12-, or 16-Channel True-Diversity Wireless Receiver with SpectraBand

Overview

The future of wireless

Meet the half-rack receiver with an entire rack’s worth of features. The next-generation A20-Nexus is expandable from 8 channels up to 12 and 16 with additional software and features forward-thinking technologies like SpectraBand, the powerful NexLink remote-control link, real time spectrum analysis, and more. With multiple options for audio outputs, powering, and remote control, the A20-Nexus can seamlessly adapt to your workflow, both now and in the future.
  • 8-channel ultra-high-performance, true-diversity receivers in a ½ rack size (8.0” x 6.6” x 1.6”).
  • Expandable to 12 or 16 channels via A20-Nexus 4-Channel Expansion License. Licenses are $2500 USD, or $250 USD for a 7-day rental, or $850 USD for a 30-day rental.
  • 169 MHz – 1525 MHz tuning range via SpectraBand Technology.
  • NexLink: an advanced long-distance modulation that allows for remote control of wireless transmitters from the receiver.
  • Dante audio-over-IP of RF receiver audio.
  • Flexible powering: via PoE+, DC input, 8-Series, or AC mains (with optional adapter).
  • Web App control from browser on any computer, smartphone or tablet.
  • Full remote operation capability: Power via PoE, audio via Dante, control via Web App.
  • Dual DB-25 connectors for 16 channels of mic, line, or AES outputs
  • Convert 16 channels of Dante to analog and/or AES on DB25 connectors, for sending IFB, voice-of-god, and more from mixer to set.
  • Wide, 6.2” color OLED array with touch for control and monitoring.
  • Integrated Real Time Spectrum Analyzer (RTSA) and scanning for intuitive frequency coordination.
  • Optical Fiber Network option via SFP slot. SFP accepts a wide variety of modular network transceivers.
  • A20-QuickDock allows docking and undocking in seconds from 8-Series mixer-recorders with no tools.
  • The AutoAssign function automatically scans the current tuning band for clean frequencies and assigns them to multiple channels. The clean frequencies are automatically pushed to NexLinked transmitters.  
  • Modular design: RF section (A20-Nexus) can be disconnected and remoted from 8-Series, as opposed to less-flexible integrated RF/Mixer/Recorder solutions.
  • All NexLink control is handled by A20-Nexus and/or its Web App instead of the 8-Series for maximum flexibility.
  • Full remote power-down: A20-TX and A20-Mini transmitters can be fully powered down via NexLink for excellent battery life. This alleviates the need for remote auto-RF-Power adjustment schemes. User is in full control of RF power settings.
  • Supports GainForward Architecture: No gain setting on the A20-Mini or A20-TX transmitters. Adjust gain at the receiver or mixer.
  • 100% digital long-range modulation delivers the longest transmission distance of any system on the market. 
  • Excellent audio quality, full 10 Hz – 20 kHz audio bandwidth.
  • RF SAW filters for excellent rejection of interference from nearby IFB or camera hop transmitters.
  • BNC timecode input for auto timecode sync of transmitters over NexLink.

SpectraBand

SpectraBand technology delivers a tuning range of 169 – 1525 MHz in a single unit – an industry first! Experience ultimate flexibility as you find open spectrum away from the crowded UHF TV band.

NexLink

With NexLink’s advanced long distance protocol, you can control your A20-Mini and A20-TX transmitters using the built-in long range remote control link. 

Network away

You’ve got options. Use the built-in web server with any computer, tablet, or phone to control the A20-Nexus wherever your ethernet cable can take you. Power the receiver from a distance using Power-over-Ethernet (PoE) and remotely deliver audio via Dante. The possibilities are boundless.

Real Time Spectrum Analysis

The days of waiting for a scan to complete are over. Instantly visualize the RF spectrum around you in real time and coordinate frequencies all while monitoring audio.

GainForward

With the A20-Mini’s and A20-TX transmitters’ GainForward Architecture, easily set the gain, low-cut, and limiter directly on your A20-Nexus or mixer-recorder. This immediate, local control of gain means never having to adjust the gain on the transmitter again. 

Go cableless

Thanks to its half-rack size, the A20-Nexus is equally at home in a rack, in a bag, or docked to an 8-Series mixer recorder for a cableless kit.

AutoAssign

Assigning frequencies to wireless transmitters used to take forever. Not with the A20-Nexus true diversity wireless receiver’s AutoAssign function. It automatically scans the current tuning band for clean frequencies and assigns them to multiple channels. The clean frequencies are then automatically pushed to transmitters linked to the NexLink protocol.

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Specifications

Patents: The A20-Nexus is protected by US patents US10678294B2, US20190166523A1, International patent WO2018022209A1, and several patents pending.

RF

  • Tuning
    • 470 to 1525 MHz (1055 MHz switching bandwidth)
    • 25 kHz steps
    • SpectraBand Technology for maximum rejection of out-of-band signals
    • Available frequencies depend on country of operation
  • Modulation
    • Proprietary, 100% digital RF modulation
    • Standard or Long Range, selectable per channel
  • Spurious Rejection
    • >100 dB typical
  • Cascade output
    • 50 ohm
    • 3.5 dB Insertion Loss from front BNC through rear BNC: It is recommended to use an external powered antenna to overcome the 3 dB splitting loss in the Nexus so that the receivers maintain excellent range.
    • Wideband power split, pre-LNA
  • RF Bias output
    • 12V, 200 mA each BNC
    • Smart antenna support, Wisycom-compatible

Audio

  • Latency
    • Standard modulation = 2 ms, analog or digital outputs
    • Long Range modulation = 3.9 ms, analog or digital outputs
  • Audio Frequency Response
    • 10 Hz–20 kHz, +/- 1 dB relative to 1 kHz
  • Dynamic Range
    • > 130 dB with A20-Mini as transmitter
  • Output Level
    • Line-level: +20 dBu for 0 dBFS
    • Mic-level: -20 dBu for 0 dBFS
  • Audio Output Sample Rate
    • 44.1, 48, or 96 kHz
  • Digital Audio Output
    • AES3 balanced connection, 110 ohm output impedance
  • Audio-Over-IP
    • Dante, 44.1 or 48 kHz sample rate

Network

  • Dante Audio-Over-IP
    • 16 input/output channels
  • Control
    • Web-based control and monitoring of all Nexus settings
  • Connections
    • 2x RJ45 ports: For Dante and/or Control. Port 1 supports powering from PoE+
    • 1x SFP: For Dante and/or Control. Compatible with Small Form-factor Pluggable (SFP) network transceivers

Powering

  • Sources
    • DC Input: dual, redundant (highest voltage takes precedence)
    • PoE+: 802.3at, 30W needed (standard 15W PoE 802.3af will not work)
    • 8-Series (through unit-to-unit connector when docked)
    • AC mains adapter (sold separately)
  • Levels
    • DC input, 10 to 18V in, 3A minimum at 6.5 VDC
    • 11 W idle, default configuration
    • Extra power passed through for USB power, active antenna power, and DC output power
    • USB-A: 5V, 500 mA output; supports keyboards, thumb drives, A20-Mini transmitters, and USB hubs

Environmental

  • Operating Temperature Range
    • -10 °C to +55 °C 
  • Dimensions (H x W x D)
    • 4.0 cm x 20.3 cm x 16.7 cm
    • (1.6 in x 8.0 in 6.6 in)
  • Weight
    • 1.27 kg (unpackaged)
    • 2.8 lbs (unpackaged)

What‘s in the box

  • A20-Nexus
  • 2 x A20-2.4G antenna + mounts
  • 2 x A20-Monarch antenna
  • 2 x adjustable clamp and articulating arms
  • 2 x BNC cables

FAQ

General

Can other manufacturers’ transmitter be used with the A20-Nexus?

No. The A20-Nexus is a 100% digital RF receiver, and all manufacturers’ digital transmission schemes are proprietary. The Sound Devices A10-TX and A20-Mini transmitter are supported by the A20-Nexus. Older, analog-based transmitters are not compatible with A20-Nexus.

Do my existing A20-Minis need to be sent in for an upgrade to get NexLink installed?

No, simply upgrade the firmware to v7.00 and you get this new functionality for free.

Do I need to pair the transmitter via USB each time I use the A20-Nexus?

No, this pairing operation is typically done once during initial setup. The A20-Nexus and A20-Mini remember their pairing after that. An A20-Mini can be paired to only one A20-Nexus receiver at a time. Before pairing with a new A20-Nexus, please unpair the transmitter first.

What if I want to use my A20-Mini with a different A20-Nexus?

Simply unpair from the current receiver and pair the A20-Mini with the new A20-Nexus via USB. The A20-Mini will forget the first A20-Nexus and now be paired with the new Nexus.

Can multiple A20-Nexuses along with their own paired A20-Minis be operated in the same vicinity as others? For example at a sporting event or adjacent sound stages without interference from others?

Yes. NexLink was designed from the ground up specifically for this sort of situation. Each A20-Nexus’ NexLink stream is encrypted with its own key and cannot be accessed by other units.

Does the Nexus automatically know whether it’s docked on a 8-series mixer/recorder, connected to an 8-series mixer/recorder via Dante, or operating standalone?

The A20-Nexus automatically senses when it’s docked and connected with an 8-Series. The A20-Nexus and the 8-Series can pass audio in the standard manner via Dante.

Are all the same menu systems and NexLink controls available when connected via Dante, as compared to when docked to an 8-series mixer/recorder?

Control of a remote mounted A20-Nexus is done via a web app. The A20-Nexus can be remote mounted hundreds of meters away, and all of its controls are available on any device with a web browser connected to the control network. This could be a phone, tablet, or computer. When docked to an 8-Series mixer/recorder, these controls are available on the A20-Nexus front panel screens.

I assume only a single A20-Nexus receiver can dock to the 8-series using the A20-QuickDock?  If a user has two A20-Nexus receivers, would it be more advantageous to connect both receivers via Dante?

Yes, only one A20-Nexus can be docked to the expansion port on the 8-series mixer/recorder at a time. The user can decide if the Expansion Port, Analog, AES Digital, or Dante audio connections are most convenient for their application.

Can I hot plug the A20-Nexus using the A20-QuickDock?

No. Please power the system down before docking or undocking an A20-Nexus with an 8-series mixer/recorder using the A20-QuickDock accessory.

How do you update the firmware on an A20-Nexus? Via USB?

Yes. Start by formatting an empty USB flash memory drive via the USB-A port on the A20-Nexus. Then, copy the firmware update (.prg) file to the root of this USB drive. Connect the USB drive to the A20-Nexus, navigate to the System Menu, and select Firmware Update.

Does the Nexus have any display output?

Via the web app, yes.

Why didn’t you design the mixer-recorder and the wireless all together into one box?

We specifically did not design an all-in-one solution, but rather two distinctly separate boxes. This way the RF receiver can easily be undocked and remote mounted for ultimate flexibility. Additionally this allows one Nexus to be used amongst several 8-Series recorders.

What is the list price of the software channel licenses?

The channel count of the A20-Nexus can be increased from 8 channels to 12 by purchasing a +4 channel plugin license for $2500 USD, adding an additional 4 channels to increase from 12 to 16 with another +4 license for $2500 USD, or doubling the channel count from 8 to 16 with a license listed at $5000 USD.

Remote Control

Can NexLink be used to control my A20-Mini transmitters when the A20-Nexus is docked with an 8-Series mixer-recorder?

Yes. All control of the remote transmitters is done via the screens on A20-Nexus or via the A20-Nexus web app.

Is NexLink’s range better than Bluetooth?

Yes, by a wide margin. Bluetooth is good for 10s of meters, NexLink is good for 100s of meters.

What about Bluetooth Long Range mode?

NexLink still beats it by a long shot – at least 8 times the distance. Bluetooth Long Range is an optional mode of Bluetooth which does increase its distance, but still not long enough for complete control of wireless microphones.

Does NexLink only work line-of-sight?

No. NexLink is designed to work in all environments even those with many obstacles.

Do I need to worry about setting channels for NexLink?

No, NexLink is fully automatic. Simply pair the A20-Mini transmitter to the A20-Nexus once via USB, and NexLink automatically assigns it to a receiver channel. Now any changes (RF frequency, RF Power, Modulation etc) you make to the receiver channel will be automatically NexLinked to the transmitter

What parameters can be controlled via NexLink? Is it the same as the A20-Remote app or are there any expanded features?

All the same parameters controlled by the A20-Remote app can be controlled via NexLink

Can NexLink and A20-Remote be used at the same time?

Yes

What range can be expected for NexLink?

More than the UHF RF audio link, even at the 40 mW Tx power setting. Typically several hundred meters, but as with all things RF, it depends on many variables.

Can multiple transmitters be group controlled, similar to the A20-Remote app?

This is planned for a future firmware release.

If I have one A20-Mini transmitter sending audio to 2 or more A20-Nexus receivers, which receiver controls NexLink, or is it both?

Only one A20-Nexus may control a specific transmitter. It is not possible for Nexus receivers to control the same transmitter.

Can I use the A20-Monarch antenna with other wireless systems?

Yes. The A20-Monarch is a passive omnidirectional antenna with consistent gain across the SpectraBand range of 470-1525 MHz. It can be used with any wireless systems operating in this frequency range.

Can I use any 2.4GHz antenna for NexLink?

To comply with local regulations, the supplied ½-wave whip antennas should be used. There is no need to use higher gain antennas or external power amplifiers since the range of NexLink exceeds the RF audio link.

Audio

Can I send audio over NexLink? No.

No. NexLink was designed from the ground up for very reliable, long-distance control and synchronization only. NexLink trades off data speed for extreme long range.

Can I use the Dante built into the A20-Nexus as a Dante port when the A20-Nexus is docked to the 8-Series mixer/recorder?

No, the Dante and all of the other A20-Nexus rear panel connectors (other than the USB-A and Ethernet control ports) are disabled when docked to an 8-Series.

Why does Nexus have 16 Dante transmit channels?

This is in preparation for when we release the +8 receiver channel plugin – Nexus will be capable of sending a total of 16 channels over Dante.

Can the Nexus send Dante audio and be controlled via fiber-optic network cable?

Yes, with an appropriate SFP plug-in module, many types of fiber-optic network cable can be used to send Dante audio and control data to an A20-Nexus many kilometers away if desired. Follow your network hardware manufacturer’s recommendation for SFP modules. For generic SFP modules, a good starting point is: https://www.fs.com/

Powering

Can you set between Lithium AAA & Sony NP-BX1 battery from Nexus, or this is automated?

The A20-Mini itself automatically senses the battery type and selects the correct powering – no need to set anything on the A20-Remote app or with NexLink.

How many transmitters could NexLink control? Is it a maximum of 16 transmitters per Nexus?

At initial release, NexLink can control 16 transmitters at a time. The protocol is scalable to handle many more.

Does NexLink work with A10-TX?

No, the A10-TX does not have NexLink radio hardware built-in, only Bluetooth. The A20-Mini has both Bluetooth and NexLlink hardware built-in.

Do you have to manually change settings when an A20-Mini has an A20-BatteryDoubler installed? Or is this automatic?

For more accurate battery life indication, a setting for the A20-BatteryDoubler needs to be manually engaged on the A20-Remote app or on the A20-Nexus interface.

Can the A20-Nexus TA4 DC power inputs be used for redundant powering of an 8-series mixer/recorder when docked with an 8-series?

No, the DC inputs and outputs on the rear of the A20-Nexus are totally disabled when connected to an 8-Series.

How much power is available on the A20-Nexus USB-A port? What about the USB-C port? Can I charge my phone with it?

The USB-A port can provide up to 500 mA of power. The USB-C port is for factory test and does not provide power. As such, we do not recommend using these ports to charge devices via USB.

RF

Can Nexus automatically assign frequencies to connected transmitters?

This is planned for a future firmware release.

Can Nexus automatically switch transmitters to free/higher quality frequencies? If so, can backup frequencies be pre-set?

This is planned for a future firmware release.

What tuning bands are available?

All legal frequencies from 470 MHz – 1525 MHz.
The bands are different depending on which country you are operating in.
Please see the Sound Devices Available Frequencies for more information

Can multiple tuning bands be used at the same time? / Do all channels need to be in one tuning band?

One tuning band needs to be selected (generally 24 MHz wide), and then all channels need to fall withing this band.

Can multiple channels be set to a mix of Standard and Long Range modes?

Yes

If two receiver channels are set to the same frequency, will this cause any problems?

This works just fine. With A20-Mini, only one of the receiver channels will control the transmitter via NexLink.

Can the A20-Nexus provide bias power to a remote antenna? And can it control a smart antenna?

Yes, the A20-Nexus can provide bias power and can control selected smart antennas.

Which smart antennas can be remotely controlled by A20-Nexus?

A20-Nexus supports the Wisycom smart antenna protocol. We have specifically tested it with both the LFA and BFA models, but other versions should work as well.

Can the front mounted and rear mounted BNC antennas be used simultaneously?

Via the RF Settings Menu, either the front or the back BNC connections can be selected as the RF input. Antennas could be connected to both the front and the back simultaneously without harm.

Does the A20-Nexus automatically detect whether the front or rear antenna input is being used?

No, this is a manual setting in the RF Settings Menu.

Can the A20-Nexus output RF to connect additional units together?

Yes, when the front BNC connectors are selected as the RF input, the rear BNC connectors can be set to cascade output. This cascade is done with a very wide bandwidth, very low distortion passive power splitter. As such, there is roughly 3.5 dB of loss when the cascade output is engaged. This should be accounted for in an RF gain calculation and an active antenna may be preferred in this configuration.

Does the RF filtering happen after the cascade connection?

Yes, the cascade connection is done with a very wide bandwidth, very low distortion passive power splitter. This split happens before the RF filtering.

Is the gain on the A20-Monarch sufficient for cascading two receivers?

This will depend on the RF gain calculation mentioned above, but a general recommendation is one cascade connection when using the A20-Monarch antennas.

What’s the difference between Standard and Long Range Modulation?

When compared to Standard Modulation, Long Range has better sensitivity. This results in more robust performance in challenging RF environments. Standard modulation has a latency of 1.9 ms, while the long range modulation has a latency of 3.9 ms.

What’s the best practice for using A20-Nexus with an IFB or Camera Hop transmitter nearby?

It’s always best practice to separate your transmit and receive antennas as much as is practical. A20-RX includes robust front end filtering designed to minimize interference from strong nearby signals. We recommend placing an IFB or Camera Hop a minimum of 12 MHz outside of the tuning band. For example, if your A20-Nexus is set to the 564-588 MHz tuning band, place your IFB or Camera hop below 552 MHz or above 590 MHz.

What are the advantages to SpectraBand tuning?

Based on feedback from our user community, we designed SpectraBand to address two common problems, crowded RF spectrum and strong interfering signals. First, the 470-1525 MHz tuning range is unprecedented in a wireless microphone receiver.  This opens up additional spectrum that is unavailable in other products. It eliminates the need for multiple pieces of hardware to cover these various frequency ranges. Second, we include robust front end filtering utilizing SAW filters that minimizes interference from strong nearby signals. This allows you to work in closer proximity

RTSA Scan

Can the Real-Time Spectrum Analyzer (RTSA) run while receiving all audio channels, and can NexLink work at the same time?

Yes, the RTSA works at the same time as all of the audio receive and NexLink can function without interruption – this allows you to view the full tuning band spectrum in real time. The RTSA is very useful to monitor the RF spectrum visually while listening to the audio.

When running a scan, does this stop audio receive?

The wide band scan function is different from the RTSA mode. The scan function is used to select an appropriate Tuning Band. During a scan, audio receive is stopped.

Can you monitor the RTSA via the Web app while monitoring the channel settings on the front panel?

Yes. The Web app operates independently of the front panel controls and the information displayed can be different.

Web App

Can the live Real-Time Spectrum Analyzer (RTSA) be viewed when connected to the Web App?

Yes, it is very easy to connect to the A20-Nexus web interface via phone, tablet, or computer and view the RTSA.

What IP access pointWhat wireless access point can be used to wirelessly connect to the A20-Nexus control network port? can be used to wirelessly connect to control the A20-Nexus over IP?

The A20-Nexus uses standard IP network protocols and there are hundreds of available wireless access points which could be compatible with the A20-Nexus control network. For portable applications, Sound Devices has tested the GL-iNet Slate and Slate Plus travel routers (Models GL-AR750S and GL-A1300) and found they work well and conveniently draw power via a standard USB port.

Can I access the A20-Nexus web app via any device, i.e. laptop, tablet, phone?

Yes. Additionally with an appropriate VPN tunnel, this web app could be accessed from anywhere around the world.

Do I need an app or driver installed to access the A20-Nexus web app, or is it accessible through any browser?

Nothing special needed, just a modern web browser.

Which SFP module should I use if I want to run a fibre-optic network cable?

The A20-Nexus will accept an SFP conforming to SFP MSA (INF-8074i). SFPs tested by Sound Devices include FS #75322 (10/100/1000BASE-T), FS #75326 (1000BASE-LX/LH), and the FS #75339 & 75340 BiDi pair (1000BASE-BX). Many others may work and we recommend testing in your specific network environment.

Network

Can I reconfigure Nexus IP address information?

Yes, the Network Settings menu lets you set a static IP address, or enable DHCP to obtain an IP address automatically. If DHCP is enabled and no DHCP server is found on the local network, the A20-Nexus will fall back to a link-local IP address.

Accessories

Astral VHF Whip Antenna (SMA)

View

A20-Nexus 4-Channel Expansion License

View

A20-QuickDock-Pegs

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A20-2.4G Ant

View

A20-2.4G Ant+Mount

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A20-Shelf

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A20-Monarch

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A20-QuickDock

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PowerStation-8M

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XL-WPTA4

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