AUDIO LIMITED A10-TX Digital Transmitter
AUDIO LIMITED A10-TX Digital Transmitter
AUDIO LIMITED A10-TX Digital Transmitter Top Connector
AUDIO LIMITED A10-TX Digital Transmitter Top Connector
AUDIO LIMITED A10-TX Digital Transmitter Internal Power
AUDIO LIMITED A10-TX Digital Transmitter Internal Power
In a nutshell

The Audio Limited A10 RF system is an evolution of the English brand's (purchased in early 2018 by the US Sound Devices company) first digital RF system then called RMS 1010 and released in 2015. It consists of the A10-TX pocket transmitter powered by two LR6 AA batteries or cells and the True Diversity standalone dual-channel broadband A10-RX receiver compatible with the SuperSlot format.

Unlike standard frequency-modulated analog RF systems, the A10 digital RF system works mainly in amplitude modulation over a wide UHF band 470-694 MHz divided into 4 sub-bands: A 470-548 MHz, B 518-608 MHz, C 594-694 MHz and D 534-629.8 MHz. It is possible to place up to 20 frequencies on 8 MHz or even 15 on 6 MHz in 25 kHz steps.

Both the RF modulation signal and the digital encoding use brand specific codecs. It is therefore not compatible with any other digital RF system.

Digital transmission is less subject to intermodulation and requires a lower signal-to-noise and signal-to-interference ratio than analog FM transmission. On the other hand, a saturation of the reception signal leads to a loss of sound signal! This excludes the use of amplified antennas too close from transmitters. To avoid this problem of audio signal interruption during reception, it is possible to set the transmission power between 10 mW, 20 mW and 50 mW.

The A10-TX transmitter allows you to connect to the same 3-pin Lemo input, either a lavalier microphone (asymmetrical electret with 5V polarization), a dynamic microphone, or a static microphone (symmetrical with 12V or 48V Phantom power supply) without the need for an additional power supply module such as LC-48 or Lebel PWL III, or a line level source. Except with an electret, it is necessary to use the special AC-BALXLR cable which filters high frequencies.

For this transmitter A10-TX Audio Limited has designed a new analog microphone preamplifier with very low noise and high dynamics that accepts both very low mic level and high line level signals. It is provided with a low-cut filter (40, 60, 80, 100, 200 Hz at 18 dB/octave) and a non-adjustable but deactivatable limiter. The input gain is adjustable in steps of 1 dB from 0 to +40 dB for electret levels, -10 to +16 dB for line levels, 36 to 60 dB (16 to 40 with PAD enabled) for balanced microphones. With a 20 Hz-20 kHz frequency response and a non-destructive digitization codec, the audio quality of the RF boom is close to that of a cable boom.

The A10-TX transmitter has a complete time code generator whose signal is available on the Lemo 3 connector. It includes a miniature recorder on a micro-SD card formatted in FAT32. The files are in proprietary .mic format with timecode that must then be converted into .wav (BWF) with Mic2Wav software utility available for PC or Mac (on MacOS it is necessary to first install the VCP CP210x USB to UART Bridge driver). Please note that the recorder function is not available in the USA for patent issues filed by Zaxcom in that country.

Transmitter settings are possible either via an intuitive menu on a large, easy-to-read OLED display, or partially on an Android or iOS smartphone with the A10-TX Remote App. This allows you to rename the transmitter, view the TC, check the power status, enable/disable standby, start/stop recording, set the input gain, low-cut filter, transmission power, frequency or RF channel.

The A10-TX transmitter despite its rounded shape remains quite impressive, certainly less cumbersome than a 2020/2040 transmitter but relatively more than a Wisycom MTP41, a Sennheiser SK 5212 and much more than a Lectrosonics SSM with Digital Hybrid technology.

Its consumption necessarily depends on the transmission power, the source (electret, dynamic, static microphone or line) and the use of the recorder function. With alkaline batteries, it goes from 1h30 with a 48V microphone and a transmission power of 50 mW to 4h for a power of 10 mW with an electret lavalier microphone. With Ni-MH batteries (2450 mAH) this doubles the time. In recording mode only it goes from 14h30 with alkaline to almost 19h with Ni-MH or even 33h with Li-Ion batteries.

Our recommendations

The use of the special AC-BALXLR cable to connect a 48V static microphone to the A10-TX transmitter is not sufficient to filter the RF and electronic radiation it produces. The microphone should be kept as far away from the transmitter as possible, the usual placement at the boom head is not always possible and the position of the antenna is crucial. At a minimum, the transmitter must be transferred to the boom operator following a 5-6 meter cable, at best to an even more distant point, for example on a boom stand base near the boom operator. Some microphones are more sensitive than others. Only the Neumann KM 185 (and the KM A series) and the Sennheiser 8000 series seem to allow use without distance. Schoeps CMIT, CMC, CCM need to be far away. The use of Neumann KM 100s is prohibited.

 / Write Review
Technical specifications

A10-TX émetteur de poche miniature UHF numérique multicanal.
560 fréquences par groupe de 20 pour 28 canaux de 8 Mhz sur une plage de 223.6 MHz divisée en 3 sous-bandes :
A 470-548 MHz, B 518-608 MHz, C 594-694 MHz et D 534-629.8 MHz.
Porteuse de 470.2 à 693.8 MHz (version EU).
Réglage par menu sur écran OLED. Télécommande par Bluetooth.
Limiteur analogique débrayable dans menu.
Réglage par pas de 1 dB du gain (électret, micro, ligne, 48V, 12V) de -10 à +60 dB, indication de niveau et crête sur OLED et led; indication de pile faible sur OLED et led.
BP : 20 - 20 kHz, filtre passe-haut 40, 60, 80, 100, 200 Hz à 18 dB/octave.
Puissance HF 50 mW, 20 mW ou 10 mW.
Alimentation intégrée pour microphone symétrique Phantom 12V et 48V et microphone asymétrique électret 5V.
Enregistreur avec timecode intégré sur microSD FAT32.

Conn. audio ou tc Lemo 3 pts. à vis x 1, conn. HF SMA coax. à vis x 1.
Alimentation interne 2 piles LR06 1.5 V
Autonomie env. 2h20 à 50 mW, 4 heures à 10 mW (alcalines avec électret), 1h30 à 50 mW (alcaline 48V).
Dimensions 8.3 cm x 6.4 cm x 1.8 cm, masse 0.104 kg avec piles.

Manufacturer's documents