Forgotten electronics

17th March 2023 By: Terry Mackenzie-hoy

Over the various years, there have been a number of instances of electronic devices which have been invented that have been widely used and then which have been surpassed and finally overtaken by other electronic devices to the point that they have been completely forgotten.

It is probably not really worth knowing what these devices are, but there is some interest in the subject, so I thought I would write about it. Let’s go back to the valve.

As reported in an article on Wired.com on November 16, 2007: “1904, British engineer John Ambrose Fleming invented and patented the thermionic valve, the first vacuum tube. With this advance, the age of modern wireless electronics was born.

The vacuum tube, a diode (having two electrodes) would have far-reaching applications. The tube was standard equipment in radio receivers, radar sets, early television sets and other forms of electronic communication for at least half a century, until it was replaced by solid-state electronics in the mid-20th century.”

The report may say it was replaced by solid- state electronics in the mid-20th century, but some of it was not replaced until quite a bit later. Whatever the case, the fact is that now tubes and diodes are virtually unknown and have no useful purpose. Almost. The ‘almost’ comes because they are still used in very sophisticated audiophile applications for people who want to be able to hear the response of audio over a complete frequency range.

Going back to the devices which have been invented and then surpassed, it is a fact that there is quite a large range over which various audio files can vary. One would think that audio reproduction is a flat response of audio files over a given range. By this it is implied that any audio response is similar for various audio devices. In other words, a given amplifier will make the same noise, given the same audio input as another amplifier. In fact, this is not the case, and one of the difficulties we have is to distinguish between audio systems and music systems. In other words, we find that an electronic system and a musical system produce a different output based on the different input.

A big challenge that faced engineers and the electronic technicians at beginning of the last century was to produce an electronic system which sounded the same as a musical system, given that the musicians would have to produce their music differently for each system. Actually, they haven’t yet got it completely right and reproduction of music electronically still differs to some degree from the reproduction of music without using electronics.

You may want to reread what I’ve just written. Nonelectronic music can only be reproduced with an amplifying microphone mounted in front of it. Electronically reproduced music has an amplifier built into it. The problem of this is that, for nonelectronic music, you are committed to having two forms of reproduction – that of the instrument and that of the amplifier. The reproduction by the amplifier is never going to be the same as that of the instrument and, in a similar way, it will never be exactly that of the electronic system. A further problem is the people who want to reproduce the music from either system are normally quite careless about it and try to over-reproduce in one case and mis- reproduce in other cases.

One of the best projects we ever did was to do the acoustics for the City Hall in Cape Town. The reproduction was superb. I expected it to be so because we had taken a considerable effort to get the reproduction throughout the hall correct and nonelectronic. In the end, it was a pity as they said the first reproduction was so badly amplified and sounded awful. The two ladies who sat behind me spent most of the evening talking to themselves and spoke slightly louder to make their voices heard over the sound of the music.