Compton Electrone Organ

[ChrisLawton43]

Hi all,

I have at home a 1950s Compton electronic organ which Compton called the 'electrone'.

Compton were famous for their cinema organs in the 1930s of course such as the Odeon Leicester Square and also pipe organs at places like BBC Maida Vale and Downside Abbey.

In the 1920s, Compton patented their electrostatic tone generator which was first used on their cinema organs between 1935 and 1939 and called the 'melotone'. It provided ethereal sounds which complemented the traditional wind blown pipes and could transport your mind in ways that pipes alone could not.

By the end of the 1930s this device was developed into a complete 'pipeless' organ for both church and entertainment use.

After the war, the company developed a whole variety of electronic models and I am lucky in having one such example dating back to the late 1950s.

Back in the summer, the organ developed a fault with the motor and I thought that was the end. However, Lucien Nunes (who introduced me to this forum) came up and not only sorted out the problem but pretty much overhauled the organ to the point where it is probably in better condition than it has been for many years. His wiring is so perfectly neat that it's a pity it can't be seen.

Thanks to Lucien, I now have an organ which is good for another 50 plus years so that should take me up until I am now 93!

For your interest, I produced a video for youtube telling the story of the organ when she was 'unwell' to Lucien performing his magic to the end result.

Hope you enjoy!

https://www.youtube.com/watch?v=bYgiPqhzvWk

[McMurdo]

Funnily enough I was playing one of Lucien's tv interviews on youtube last night to show the other 'alf and it automatically linked to your videos after Lucien's finished.

[Brigham]

A splendid video.

The tone generators are just like the theatre type, but much smaller, and without the rumble and clatter.

[Lucien Nunes]

Rumble? Clatter? Are you suggesting that Compton tone generators might have had some issues with background noise?

Compton made about ten different types of rotary electrostatic tone generator, starting with the large type found in cinema-organ Melotone attachments where the entire compass of the instrument is covered by two units. Each pitch is available with one waveform only, and the need to make the waveform ends 'meet up' around the discs prevented the tuning being accurately even-tempered.

By 1938 Compton were producing stand-alone electronic organs, Theatrone (for entertainment) and Electrone (for classical music) which used 5-inch diameter generators. Twelve generators, internally identical but running at different speeds, provide the twelve semitones / pitch classes of each octave. Prewar versions of these generators have two different waveforms available, while in 1947 the design was updated to include four different waveforms each offering between five and eight octaves.

Various developments and elaborations appeared over the next few years with increasing numbers of traces and ranks packed into the same space. These allowed better simulation of pipe organ tones but tended to lower the signal-to-noise ratio of the generator itself and also expose the SNR of the amplifier due to the lower output per trace. It became necessary to insert a muting relay in the audio signal path to silence the instrument when nothing is being played. Such arrangements became quite common on electronic instruments generally, although mainly to eliminate 'bee-hiving' where all pitches are heard simultaneously in the background due to keyer crosstalk. In the Compton it is mainly to combat noise from the generators themselves.

In 1952, Compton launched a new generator that returned to one waveform type, used in conjunction with additive synthesis (like a Hammond organ, and covering the same tonal range and compass). With only seven traces, it was possible to make these half the size at 2.5 inches diameter and use a smaller motor. The new 2.5-inch generator system was compact enough to fit within a standard 2-manual console and offered lower cost and better SNR, at the expense of less subtlety and scope of the pipe tones they could produce. Ultimately, by numbers, most Compton electronics produced in the 1950s and 60s used 2.5-inch generators, which were further updated in 1963 as were the 5-inch types now used in only the very large instruments.

For more background (noise?) see http://www.electrokinetica.org/d8/2/index.php

[lesmw0sec]

Most interesting. I'd not seen the inside of one of those before!

[Brigham]

https://www.youtube.com/watch?v=5VrLu0qYOTI