A discussion of the Williamson Amplifier should be first preceded by an overview of its context in the evolution of the vacuum tube and its application to high fidelity audio reproduction. Transformer coupling was widely used pre-war because it was simple and effective. It was widely used throughout WWII and later - particularly for public address amplifiers and radio transmitters.
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But transformers were expensive, used scarce and expensive raw materials, and performance was generally limited by the transformer characteristics to a frequency response flat from about 20-20, 000 Hz at best and 100 to 5, 000 Hz at worst. Distortion was high due to the use of transformers (low quality by modern standards) and no negative feedback of any kind. Hum, noise and microphonics would have been barely tolerable. Loudspeakers were improving at a rapid rate and their frequency response capabilities were creating listener awareness of the limitations of the amplifiers of the era. This was a time when large numbers of military personnel were being returned to civilian life and the British economy was in a state of new growth and development. There was interest, motivation and social approval for people interested in good quality audio to think about it and, if possible, improve their pre-war equipment - by then at least seven years old and most likely much older (a long time in those days). Pre-war valve audio obviously did not include the significant advances made in vacuum tube technology and componentry throughout the world during the war years, so the time was ripe for consumers to upgrade to the benefits of that technology. Throughout the 1930`s, British valve manufacturers had faced stiff volume and price competition from imports, sourced primarily from the USA. There was much bad blood between the British...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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