Gaumont-Kalee Type 893

This microphone comes in an elegant fitted wooden box with an engraved name plate which reads "Gaumont-Kalee microphone type 893. Made in London England by Rank Precision Industries (BAF) Ltd.". The three different brands on the label should give some clues as to the age of the microphone.

The company British Optical & Precision Engineers Ltd, was founded in 1948 and, according to a memo from Mr. T.A. Law to staff, changed its name in 1956 to Rank Precision Industries Ltd. This was part of a larger reorganisation and re-branding of various companies related to the Rank parent company, and the British Acoustic Films Ltd. became Rank Precision Industries (BAF) Ltd.

According to the British National Archives, Rank Precision Industries (BAF) Ltd. was dissolved in 1963, and so we can date our microphone as having been made between 1956 and 1963 with a good degree of confidence.

The 893 is super rare and are only aware of one other example, which is in the collection of a British rental company Cinephonics. They describe it a follows...

"Circa: Late 1940's - Late 1960's. Ex Pinewood Studios Sound Dept. A microphone that is of exceptional sound quality, used for both film sound and music recording".

MoMics Notes:

In the absence of any official specifications, we have done our best to measure and document this microphone.

Even before looking inside, we can see that is has a prominent white stripe along the back of microphone, which tells us that it is a directional microphone intended for use on a film or TV set. The stripe allowed the microphone boom operator to point the microphone at whoever was speaking on stage.

The ribbon gap is 4.1 mm wide and 37.4 mm long, and the ribbon itself is clamped to a removable frame which simplifies any necessary maintenance. A filter network of a resistor and two capacitors is positioned above the ribbon

The transformer has dual windings in order to reduce hum, and has the options to be wired for 15 or 300 ohm output impedance. Unfortunately this particular transformer has a low output level and is suspected to be faulty, with some degree of internal leakage of signal. For the sound recordings, we replaced the transformer with an Extinct Audio B-series model, which raised the output by 6dB for the same output impedance.

This microphone uses the same 3-pin plug as the Reslo microphones that were made in the 1960s. The pins that are closest together are used for the balanced output from the transformer, and the third pin is wired to ground inside the microphone. The 893 has the same cast metal base part as the 492 and 1492 models.

The frequency chart shows the response of the Gaumont-Kalee 893 with (Red line) and without (Blue) the optional blast shield in place.

Martin Mitchell's Microphone Blog

Xaudia Microphone Blog - a post about the GK 492 and 1492 models

Gaumont-Kalee Company History at Graces Guide

The history of Rank Precision at Graces Guide

A website dedicated to the history of the British Acoustic Films (later Rank Precision Industries and then Rank-Xerox) factory at Mitcheldean in Gloucestershire.