Epoch Radio Manufacturing Co Ltd. (1928 – 1935)
53, Gracechurch Street, London, EC. (1928)
City Office and Service Station, 3, Farringdon Avenue, London, EC4.
Exmouth House, Exmouth Street, London EC4 (1932)

Radio Development Co. (Props: Epoch Reproducers Ltd.) (1935 – 1939)
Aldwych House, Aldwych, London WC2 (1935- 1937)
Epoch House, 101-105, Goswell Road, London, WC1. (1937)

Brand: Epoch

Epoch brand loudspeakers were manufactured by the two companies above from 1928 till 1939.

In 1935 advertising in British radio magazines from Epoch Radio Manufacturing Co. Ltd. ceased and Radio Development Co. started.

It is not known at present how the two companies were affiliated apart from manufacturing and marketing the same product.

Epoch Radio Manufacturing Co Ltd. (1928 – 1935)

Manufactured Epoch brand loudspeakers from 1928 – 1935.
They were distributed by Epoch Electrical Society Ltd. from 1928 to 1930. [1]

From 1931 they were distributed by the manufacturer.

An example of their products was described in the December 1932 edition of Practical Wireless.

A fine range of moving coil speakers is given in the latest catalogue issued by Epoch Radio Manufacturing Co. Ltd. Amongst the various instruments listed is, model 99K, a permanent magnet speaker with a sensitivity of a very high order. This speaker is fitted with an interchangeable diaphragm. There are also model E8, a powerful D.C. speaker designed for incorporating in modern A.C. sets where the field coil can be used as a smoothing choke; and model D2S, a powerful unit for heavy work, and capable of handling 10 watts undistorted input. Interchangeable diaphragms in three tonal characteristics are available for this speaker, and a useful impedance snatching chart printed in the catalogue shows at a glance the diaphragm suitable for the required transformer ratio and valve impedance.  [2]

Also, in the September 1933 edition of Wireless Constructor.

Stand No. 2 We wonder if there is any manufacturer who makes more types of loudspeakers than Epoch. If so, he must have a job to find anything in the way of types or sizes that are not covered by this enterprising firm.

Matched pairs, permanent magnet models, mains and battery-energised types, and so forth, are listed in abundance, while a goodly selection is to be seen at the Exhibition.

Among the latest models being introduced to the public for the first time this month is a Super-Dwarf speaker for motor cars and portable sets. This is especially timely when all the trade and listeners are discussing car radio. Another type that is making its bow is the redesigned A2, which carries various improvements while there is also a new large Super P.M. model at a popular price.

All the popular models are available for "Class B," but in addition, a special adaptor combination " Class B" speaker for attachment to ordinary battery sets is a particularly interesting newcomer. The valve Is placed in the back of the speaker, together with the necessary transformer coupling, so that in an instant an ordinary set is transformed to " Class B " with the speaker already attached. Very cute. [3]

Advertising by Epoch Radio Manufacturing in the British popular radio magazines had ceased by late 1934.

Radio Development Co. (Props: Epoch Reproducers Ltd.) (1935 – 1939).

It is not clear what happened to the company however a new company Epoch Reproducers, Ltd. appeared at the Olympia National Radio Exhibition in August 1935 with a description of their display advertised in Practical & Amateur Wireless.

Epoch Reproducers, Ltd., Stand No. 47.

The Epoch speakers need no introduction, and in addition to familiar models we shall see on this stand the following new items; Model 66 a new 2 OC model with Alnu-magnet; a new Super Dwarf and a new Moving Coil Microphone Type 55.

The new 66 Model will handle 6 watts (undistorted speech) without any trace of overloading and has a 10in. diaphragm. It costs £4 12s. 6d.

The Super Dwarf is a 5in. loudspeaker with a permanent magnet and will handle 2½ watts, yet will give splendid results with an input as low as 250 milliwatts. The price is £1 1s.

Many other interesting speakers may be seen on the stand, and those who are interested in real volume and quality should not fail to inspect the Super Cinema model. [4]

Epoch components advert from Practical & Amateur Wireless August 1936;

Two new catalogues have just been issued by Radio Development Company, one dealing with the new season's range of Epoch loudspeakers and microphones, the other giving full details of the Epoch Service, and their short-wave components.

Many new features have been added to the already excellent range of loudspeakers, including the Super-Cinema models, the D4 P.M., the B7 P.M., and the New Century  P.M. speaker, which will handle inputs up to 4 watts and is priced at £1 15s

A popular midget speaker is the Epoch Super Dwarf model, which is only 5in. In diameter and 2¼in. deep. It will handle an input of 2½ watts.

Public address horns and output transformers are also listed, and at the end of the catalogue Is a useful table for quickly determining the transformer ratios for correctly matching various speech coil impedances to various loads.

In the other catalogue, which deals with the Epoch Service, is listed a full range of accessories for every conceivable need. The aim of the Audio Development Company is to establish a central house where replacement parts can be obtained promptly, and all the parts In the catalogue are listed at net prices to save the dealer unnecessary work. [5]

On March 2, 1939, Halford Radio advertised they had taken over the manufacture and service of Epoch Speakers. [6]

[1] Wireless World Oct 3, 1928, Page Ad 43.
[2] Practical Wireless Dec 24, 1932, Page 712.
[3] Wireless Constructor Sep 1933, Page 225.
[4] Practical Wireless Aug 17, 1935, Page 615.
[5] Practical & Amateur Wireless Sep 26, 1936, Page 57.
[6] Wireless World Mar 2, 1939, Page 212.