CANFORD XLR IN-LINE RF FILTER
Although input stages today can provide a high degree of RF rejection, they are never totally immune and location recording, temporary installations and outside broadcast can pose particular challenges. Even using good quality screened star-quad cables (from Canford) still leaves a degree of risks that an AM radio signal will get into your equipment and be demodulated and this RF rejection filter can then save the day, or more often the evening!
Radio breakthrough is normally caused by common-mode RF signals being carried through either input or output cables acting as aerials and with the active electronics of the mixer or recorder providing a demodulator. The Canford RF immunity filter is plugged into the problem circuit at the mixer end of the cable and provides an effective solution by greatly attenuating the RF signal entering the mixer. The rejection is primarily of common-mode signals so it has no effect on the balanced audio signal even in applications when it is considered necessary to maintain the frequency response well into supersonic regions.
The filter is built into a high quality, machined “barrel” with Neutrik 3-pin XLR connectors, male on one end and female on the other. The internal circuit is symmetrical making the device equally suitable for use on inputs and outputs.