Shaftesbury R

This Shaftesbury model R ribbon microphone was made at Tower Road. London, and so was probably built before 1953, when the Dulci company moved to Villers Road.*

This microphone has a different motor and magnet assembly to the later model RT. The photos show the magnet assembly of the model R on the left and the RT on the right.

One curious feature of both the R and RT is that they have no transformer inside the body of the microphone and the ribbon primary circuit connects directly to the two large pins on the rear of the microphone. A suitable transformer would have been plugged into the rear of the microphone to match the impedance to the next stage of the signal chain, although we have yet to come across such a transformer. The RT grill has regular circular holes rather than the elongated perforations of the RT. And the RT has a painted cast metal lower body whereas the R lower body is folded brass that has been solded and chrome plated.

Shaftesbury have previous form for building transformerless microphones - the Velodyne model has four ribbons and no transformer.

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*According to the Brundrit website (a collection of morse code keys and other equipment)....

"The DULCI Co Ltd was situated at the DULCI Works, Tower Road, Pound Lane, Willesden, London in 1947. By 1953 they had moved to at 97 – 99 Villiers Road, London NW2. They were manufacturers of Radios, Amplifiers, Tape recorders, Band 3 converters and Tuner chassis. They also made Morse keys for the amateur radio market. In 1959 the company was taken over by Lee Products (Great Britain) Ltd."

The Museum of Technology (UK) has a Shaftesbury microphone in its collection.

A Shaftesbury RT ribbon microphone at CPV

An advertisement in Wireless World, April 1953, page 104