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'Neutrix' Style Cannon Connectors

It has become popular to use 'Neutrix' style Cannon connectors (as sold by Maplin among others) in place of the traditional Switchcraft or ITT products for the simple reason of cost effectiveness. Most of the economy in the Neutrix style is obtained by making the complete mouldings for the free sockets in plastic, unlike the true Cannon which is all metal with a plastic insert. The plastic moulding in the Neutrix is surrounded by three metal prongs which are connected to the case but have no means of connection to the screen of the connecting cable.

As a rule no problems are encountered with this, but some microphones rely on the metal (and earthed) body of the Cannon connector to ground the actual case of microphone; obviously the Neutrix will not do this, and the microphone tends to be very prone to hum and noise while still working properly. The cure for this is very simple and involves earthing the case of the microphone internally. For example a Shure Unisphere B (one offender) can be modified by loosening the screw which holds the microphone Cannon connector in place (note - screw in to release) and removing the Cannon. A link wire is then soldered in place between the tag which supports the mounting screw and pin 1 (ground) of the Cannon.