A-FILTER Installation

Last updated April 5, 2021

The A-FILTER for Balanced Microphones adds RF immunity for microphones, specifically when connected to digital wireless transmitters like the A10-TX.

The instructions below describe how to mount the A-FILTER for Balanced Microphones into a female XLR connector.

Before starting please make note of the following:

The A-FILTER should be placed as close to the microphone as possible. The benefit of the RF filter is significantly reduced if placed downstream of the microphone connector.
Make certain to use high-quality XLR connectors. Inexpensive connectors, including many painted XLR connectors, do not provide adequate electrical contact between the connector shell and the microphone connector.
The A-FILTER does not degrade the audio signal, affect phantom voltage, or draw any power in any way.

Supplies Required

The A-FILTER RF Filter for Balanced Microphone.
High quality female XLR connector. The circuit board was designed with Neutrik NC3FX connectors.
_{AC-BALXLR (blue cap) is not compatible with the A-FILTER. AC-BALXLR-2 (black cap) already has the A-FILTER installed.}
Solder and tools for cable assembly.

Note: Installing the A-FILTER assumes knowledge of proper cable soldering and termination.

Step 1

Disconnect the XLR female connector and cleanly unsolder the existing cable from the insert. If this is a new cable assembly, this step is not necessary.

Step 2

Solder the A-FILTER circuit board to the cable. Take note of the polarity labeled on the circuit board. Solder the ground connection to the square thru-hole pad.