Germanium and Silicon diodes and transistors: Germanium and silicon are chemical elements called metalloids. Both elements are brittle and have a metallic luster. Each of these elements has an outer electron shell that contains four electrons; this property of silicon and germanium makes it difficult for either element in its purest form to be a good electrical conductor.
One way to cause a metalloid to conduct electric current freely is to heat it up. Adding heat causes the free electrons in a metalloid to move faster and travel more freely, allowing applied electric current to flow if the difference in voltage across the metalloid is enough to jump into the conduction band.
The chief difference between germanium and silicon diodes is the voltage at which electric current begins to flow freely across the diode. A germanium diode typically begins to conduct electric current when voltage properly applied across the diode reaches 0.3 volts. Silicon diodes require more voltage to conduct current; it takes 0.7 volts to create a forward-bias situation in a silicon diode.
The key difference between silicon and germanium is that the Germanium has d electrons, but Silicon does not have any d electrons.
Silicon and germanium, are both in the same group (group 14) of the periodic table. Hence, they have four electrons in the outer energy level. Moreover, they occur in two oxidation states, +2 and +4. Silicon and germanium share similar physical and chemical characteristics since both are metalloids. However, there is a considerable difference between silicon and germanium as well.
The germanium transistor was the first to be mass produced and made commercially available to the public. This transistor was used extensively in radio technology, helping to create the first portable AM radios as well as the first car radios. It was even used in a few of the first guitar effect pedals in the 1960s, primarily those such as the Gibson Maestro, the Sola Sound Tone Bender, and a few others.
Many guitarists feel that the germanium transistor creates a warm fuzz tone similar to the sound of an overdriven tube amplifier. Because of the smooth fuzz that they are said to produce, germanium transistors are still highly sought out today. Many effect pedal manufacturers have also started to release fuzz pedals that once again make use of germanium transistors.
The problems with germanium transistors are many. It is not a very common element, and the actual process of making transistors out of germanium proved to be tedious and could not be easily automated. This led to a higher priced component. Germanium transistors are very temperature sensitive and the sound that they produce will change depending on its temperature. This led guitar players to store their fuzz pedals in the freezer to cool them before important recordings. Another problem with germanium transistors is that they sometimes store an electrical charge which can also cause them to “sound different.” Finally, because each transistor had to be made “almost by hand,” each one could be different and choosing one that was a good fit for a pedal could be time-consuming at best. ~Humbucker Soup
Silicon transistors are superior to germanium in almost every way. It is easily obtainable and remains stable at much higher temperatures, it has a higher voltage threshold, it is much more sensitive to high frequencies, and it puts out more gain. Silicon transistors are much cheaper to mass produce and each one is identical. Silicon does not store voltage, and it creates the same tones unit to unit. The creation of the silicon transistor is directly responsible for the creation of the Integrated Circuit or IC chip.
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