The internal microphone fitted to the Sony ICD PX333 can give excellent results, but the unit is supplied with an external mic socket on the top of the recorder, and it is possible to fit an external high quality electret capsule into the housing, to further enhance the performance of the overall unit.

A typical capsule might be something like the famous Panasonic WM61A (although these can be difficult to find these days) or perhaps the more modern Primo EM258 - There are lots of other alternatives available online, often at very reasonable prices. The notes below illustrate how such a capsule might be employed...

Fitting the Capsule to a 3.5mm Jack Plug:

• Solder 2 lengths of c. 20 swg tinned copper wire to the jack plug terminals.
• Ensure that the centre connection is sleeved, so that it cannot short to either the second wire or to any part of the jack plug casing.

• Screw on the top of the jack plug, and cut the wires as close as possible to the top of the plug, whilst leaving enough room to easily solder the capsule terminals to the end of the wires.
• Solder the wires carefully to the solder pads on the capsule. Double check the polarity, and try to keep the heat to a minimum to avoid damaging the fragile solder pads.
• Slip a short length of heat shrink sleeving over the soldered assembly.

• Heat the sleeving so that it shrinks to allow the main support to be between the terminal wiring and the capsule surround, thus reducing the strain on the actual solder connections.
• A second (larger) sleeve may be applied over the whole plug head, to provide further strength to the assembly, if this is felt to be necessary.

• A small (4mm) windshield can be fitted onto the completed assembly.
• This additional windshield will allow for 'still air' to be created in the space between the 2 windshields, and this can reduce even quite severe external wind noise to an absolute minimum. It works very well for such a simple addition.

Fitting the Assembly into the Housing Tube:

• Plug the assembled jack into the external microphone socket on the top of the recorder.
• Turn on the record function, and engage the 'HOLD' function.
• Insert the recorder fully into the housing tube.

• Once the recorder is seated securely within the housing, fit a foam wedge between the capsule assembly and the side of the housing, to prevent any movement of the recorder within the tube.

• Fit the outer windshield.
• The unit is now ready for use, with the external capsule capable of providng a high quality signal to gain maximum benefit from the recorder.