Sound Devices A-FILTER-R Right-Angle RF Filter Circuit Board (4-Pack)

Minimize RF Noise in Wireless Microphone Setups
The Sound Devices A-FILTER-R is a right-angle RF filter circuit board designed to reduce unwanted RF interference in professional audio workflows. Intended for installation inside Cable Techniques CT-LPXLR-3F low-profile connectors, this four-pack of filters is ideal for engineers looking to harden their mic-to-transmitter signal path against unpredictable RF environments. The passive design ensures zero compromise to your audio fidelity or phantom power delivery.

Built for Use with Cable Techniques CT-LPXLR-3F
These circuit boards are custom-designed to fit the CT-LPXLR-3F right-angle low-profile XLR connector, allowing for a streamlined, professional-grade installation. Whether you're assembling lavalier mic cables or compact mic runs for boompole use, the A-FILTER-R integrates neatly inside the connector housing without altering the connector's form factor or profile. This makes it a non-intrusive upgrade for workflows that prioritize size and cable flexibility.

Improves RF Immunity Without Signal Degradation
Each A-FILTER-R unit delivers up to -40 dB of RF suppression, helping to prevent radio frequency interference from corrupting the mic signal before it reaches your wireless transmitter. Importantly, this filtering is entirely passive—it does not draw power, attenuate audio levels, or affect phantom voltage. That makes it safe for use with condenser microphones and any balanced mic line that may carry phantom power.

Optimized for Digital Wireless Transmitter Chains
The need for RF protection becomes even more critical when working with modern digital wireless systems, which are often more sensitive to noise introduced at the connector level. The A-FILTER-R offers a simple but highly effective line of defense when connecting mics to transmitters in high-RF environments like festivals, broadcast zones, or dense urban shoots. It's especially useful when working with digital wireless platforms where clean, artifact-free transmission is essential.

Requires Soldering for Custom Cable Builds
This kit is intended for professional cable builders or technicians familiar with soldering. Assembly requires solder, a soldering iron, and an Allen wrench (not included). Once installed, the filter remains a permanent part of the XLR connector, silently improving performance in the background with no configuration needed. It’s a one-time installation that continues to benefit your signal path every time the cable is used.

Perfect for Field Audio, ENG, and Film Production
Whether you're building out a location sound bag, prepping boompole cables, or refining your lavalier mic rig, the A-FILTER-R is a compact but critical upgrade. Its ability to protect against interference without impacting your mic’s tone, gain, or headroom makes it an easy choice for audio professionals who care about clean signal capture in the field.