A condenser instrument is a device used in amplifiers to change the level of the voltage coming into the circuit. It is one of the most important parts of the amplifier, as it reduces distortion when the input level is low and increases it when the input level is high. A condenser is basically a coil or plate that has a small metal disk with a plate attached on its center. The disc is filled with a material that attracts the magnetism of a magnet and changes its magnetic field. This change in magnetic field changes the frequency of the incoming electrical signal and produces an amplifier that will amplify the incoming voltage.
There are various forms of condensers in amplifiers. The most common ones are the ceramic, silicon and polypropylene types, among others. Each has its own use in the circuit, and they will have different characteristic in their operation. In general, the silicon type is used for lower frequencies and the polypropylene type is used for high frequencies.
Condenser instruments are important in amplifying the input level. The most common ones are the two stage type, which uses one coil and a plate while the second coil is called the preamp. There are also single stage amplifiers. However, these are not as widely used because the power requirements of these are generally too much for the size of the circuit. It is also possible to use the multistage condenser device. These are more complex as compared to the basic ones, but are generally used in professional recording studios as well as by musicians. They are also very common in personal audio devices.