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The Philips 4225 is a small carbon microphone from the first half of the nineteen thirties. It was probably the third model that the company from Eindhoven released.

Carbon microphones were the most used type at the time: they were reliable and delivered a high output. But they were always big and heavy which made them not exactly handy.

Philips made a change with the 4225, this microphone was only 55 mm in diameter, 20 mm thick and weighed only 180 grams.

Philips based this model on their large model 4210 and made a miniature version of it. It was a beautiful but solid model, with golden contacts, to prevent malfunctions due to corrosion.

The result was a 'little giant' which had a good sound quality and that could not only be used on a microphone stand, but could also be inserted into the buttonhole of a jacket of a reporter, or a speaker, for mobile use.

Thus the first Lavalier microphone was invented; the word lavalier, which in French means "graceful pendant," is used to designate microphones that can be worn on the body.

The lack of a microphone stand, which had always been necessary until that time, was liberating for many speakers and could lead to a more casual presentation.

Philips additionally produced a version with a special bakelite desk stand that contained batteries (2 D cells) and a transformer, the type 4247, in which the 4225 microphone was fastened, but could be easily removed.
The rotary switch under the microphone switched on the system and further functioned as volume control.

Philips then based a whole series of microphones on the 4225, the outside of which was different, but the inside the same: the 4241, with flexible metal arm, for use in the car, the 4325 hand-held microphone, the weatherproof 9523, for marine use and finally the 9526 , a chrome version for stage use.

All these microphones were made well into the forties.

To promote the new medium radio and to stimulate the sale of their radios, Philips launched 'De Stem Van De Reus' (The Voice Of The Giant) in 1929.

This was a truck converted into a mobile studio that toured for years at home and abroad (a.o. Belgium, France, Denmark and Great Brittain) and brought large crowds of people together. That way they could listen to the new miracle that the radio was.

Music was played through a record player, but speeches were also held in front of the microphone.

Perhaps this 'little giant' also contributed to that.


These and many more types feature in my book Witnesses of Words.. More information about that can be found at

wow cover


Philips 4247
Philips 4225

Top: the 4247 combination & close up of the 4225

Middle: back of the 4225 & the sound

Below: button hole use, 'Voice Of The Giant' & 40's folder

4225 back

Listen to the sound of the Philips 4225:


Philips button hole mic
1940 folder
Stem van de reus