A20-Mini FAQ

With which receiver is the A20-Mini compatible?

The Audio Limited A10-RX.

Can the A20-Mini use balanced microphones?

No, the A20-Mini is specially designed for small size, and supports lav mics only. For using 48V phantom, balanced mics or balanced line sources, please use the A10-TX.

What is the Bluetooth range on the A20-Mini?

Many things in the environment can affect Bluetooth range, but line-of-sight you can typically expect upwards of 40 feet and not-line-of-sight, upwards of 20 feet.

Can the A20-Mini use both 2-wire and 3-wire lav microphones?

Yes, unlike the A10-TX which only supported lavs which are 2-wire, the A20-Mini also supports 3-wire lavs such as the Schoeps CMR.

On the A20-Remote app, I notice a “License” icon near the frequency I have set. What is this?

This icon is a friendly reminder that you legally need a license from your local government to operate on this frequency.

I notice that the green audio LED glows with audio no matter what the GainForward gain is set to. Why doesn’t the brightness of the LED change?

The green audio LED on the A20-Mini is a very wide dynamic range indicator and thus indicates the entire dynamic range of the microphone. It is designed *not* to change with any gain settings. This indicator is used for a quick visual indicator that the microphone is working.

When is simultaneous record and transmitting available on the A20-Mini?

A20-Mini transmitters purchased in the United States of America do not have a simultaneous record and transmit (REC + RF) mode.
A20-Mini transmitters purchased outside the United States of America have a REC + RF mode. This mode is available when operating outside of the United States.
REC + RF mode is not available on any A20-Mini while operating in the United States.

How robust is the plastic chassis?

The A20-Mini’s chassis has an exceptionally high strength-to-weight ratio thanks to its aluminum/high-strength Ultem thermoplastic construction. Additionally, each piece of the chassis is curved in both directions, imparting a very stiff geometry. All together, the chassis feels very light, but extremely solid.

Why is the A20-Mini branded as Sound Devices and not Audio Ltd?

Sound Devices and Audio Ltd got married back in 2018. Though we both speak (more or less) the same language, we live in two different houses. Now you get both wonderful groups under one simple name, Sound Devices.

How many groups can I make in A20-Remote?

You can make one custom group with any transmitters you select. There is also an automatically-created “All Transmitters” group.

GainForward

Is the Bluetooth connection being used to remotely control the gain of the transmitter?

No, there is no remote control of the gain circuitry at all. There are two advantages to this over a system which does perform remote gain control of the transmitter: a) if the transmitter is out of range of Bluetooth/remote control, the gain can still be controlled by the mixer; b) the gain can be controlled as quickly as you can move the trim knob.

With GainForward’s high dynamic range, does this mean I don’t need to have low-sensitivity lavs anymore such as the Sanken COS-11 red dot? 

No, low-sensitivity microphones are still needed for very loud sounds. Lavalier microphones themselves inherently have a more limited dynamic range than larger diaphragm microphones. Even though the A20-Mini itself can handle the entire acoustical and electrical dynamic range of any lav microphone plugged into it, lavs themselves can saturate with high SPL sources. Therefore there is still a need for different sensitivity lavalier microphones.

Can I use a non-Sound Devices mixer and get the benefits of GainForward?

Yes, the A20-Mini and A10-RX can be used with virtually any brand of mixer.
When sending analog audio from the A10-RX, use the A10-RX Input menu to control gain, low cut, and limiter.
When sending AES audio from the A10-RX, allow the third-party mixer full control of gain, low cut, and limiter. When in this configuration, set the A10-RX Input menus as follows:

  • Gain = 0 dB
  • Low Cut = Off
  • Limiter = Off

I’m using a 688 with no SL-6. Can I still get the benefits of GainForward?

You can still get all the benefits of GainForward in the 688 without the SL-6 provided you use the 688’s digital inputs and set the A10-RX to unity gain (0dB). Then simply adjust the digital trim gain on the 688. Full dynamic range, and zero lag A20-Mini level adjustments.

I’m using an A10-Rack with my 8-Series. Can I still get the benefits of GainForward?

You can still get all the benefits of GainForward provided you connect from the A10-Rack to the 8-Series via Dante or AES. Set the A10-RXs to unity gain (0 dB), then dynamically adjust the received A20-Mini signal level using the digital trim gain on the 8-series. Full dynamic range, and zero lag A20-Mini level adjustments.

Can I come out of the A10-RX via the analog output and still get the benefits of the GainForward architecture? 

Yes, provided you use the gain control provided on the A10-RX itself.

Does the AES output of the A10-RX have enough dynamic range for GainForward?

Yes, AES can transport 144 dB of the audio’s dynamic range, so it is definitely sufficient for the >130 dB of dynamic range of the lav microphone.