Sound Devices A-FILTER Circuit for RF Reduction

Reduce RF Interference in Wireless Audio Systems
The Sound Devices A-FILTER is a compact, in-line RF filter circuit designed specifically for use with the A10-TX transmitter. When working in environments with high levels of radio frequency interference, the A-FILTER improves the clarity and reliability of your wireless signal by suppressing unwanted RF noise at the source. It’s an essential tool for field recordists, sound mixers, and wireless audio techs who demand clean, uninterrupted transmission without added complexity in their setup.

Optimized for Use with A10-TX Transmitters
Tailored for compatibility with the Audio Ltd A10-TX wireless transmitter, the A-FILTER is placed near the microphone end of a balanced XLR cable to suppress RF ingress before it reaches the transmitter. This positioning ensures that any potential interference is removed at the earliest possible stage, resulting in better isolation and improved audio quality across the wireless chain. Whether you're on a fast-moving set or in RF-dense locations, this filter adds a layer of protection you’ll actually notice.

Effective RF Suppression Without Signal Degradation
Despite its small form factor, the A-FILTER delivers serious performance—reducing RF interference by up to 40 dB. This helps preserve signal integrity when using lavalier microphones or condenser mics in harsh RF environments, such as event venues, urban shooting locations, or productions near major broadcast infrastructure. Importantly, the A-FILTER requires no power and introduces no audio coloration or signal loss, maintaining the clean sound you expect from professional-grade equipment.

Engineered for Easy Installation in XLR Connectors
The A-FILTER is designed to be soldered into Neutrik NC3FX balanced female XLR connectors. This ensures a secure mechanical and electrical fit that holds up under the daily wear and tear of production life. Installation is straightforward for experienced technicians, making it a low-profile but powerful upgrade to any custom cable assembly. Once installed, it becomes a passive, always-on solution that travels with the cable—no extra gear or configuration needed.

A Passive Filter That Preserves Audio and Phantom Power
Unlike some inline RF suppression devices that require batteries or alter signal gain, the A-FILTER operates entirely passively. It introduces no impedance shifts or power loss, meaning you can use it confidently with phantom-powered microphones without impacting their functionality. That makes it ideal for condenser mics and broadcast-level setups where any compromise in signal or power delivery is unacceptable.

Streamline Wireless Setups with Built-in Protection
For sound professionals aiming to keep their wireless setups lean and dependable, the A-FILTER adds protection without adding bulk. It integrates directly into your XLR wiring, requires no additional housing, and is out of sight once installed. If you're building custom cables or upgrading existing ones for use with the A10-TX, the A-FILTER is a smart, long-term solution to RF contamination in the signal chain.