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Tuesday, January 27, 2009

guitar amps



what are guitar amps? These are amplifiers that amplify the sound coming from the guitar and passing through them. The amps drive the guitar loudspeaker. When a guitar is played some sound waves are generated. These waves are then converted into an electrical signal, and fed into the guitar amplifier. Sometimes the input of the guitar amp is not compatible with the minute signal emanating from the guitar; in such a case the signal is first sent to a pre-amplifier. From the pre-amplifier the output is fed into the guitar amp.

Stages Of Work

The guitar amp works in four stages. These stages are the input stage, signal modulation stage, signal amplification stage, and the output stage.

Input

In this stage the signal from the guitar or the guitar pre-amp is fed into the guitar amp. The amplifier has some input female jacks; the signal cable is attached into these jacks. Sometimes the guitar signal is very weak, and cannot be fed into the guitar amp directly. In such situations the signal is made to pass through the guitar pre-amp before reaching the main amplifier. The impedance match between the available input signal impedance and the particular guitar amp's input signal impedance must be ensured. If there is any such impedance imbalance, it invariably causes distorted guitar sound on the loudspeaker.

Most amplifiers come with a pre-amp stage incorporated in to them. It removes the hassle of passing the guitar signal through a separate pre-amp. With such amplifiers the signal from the guitar can directly be routed through the amp itself.

Signal Modulation

The electric guitarists do not like the idea of plain music coming out of the loud speakers. They are happy if the guitar sounds can be jazzed up. The twangy, the funky, and the heavily distorted sounds are well liked by them. For example if a guitarist wants to incorporate the heavy metal rock sound into his guitar sounds, the input signal will need to go through the required heavy distortion. Similarly to produce wa-wa sounds or reverb etc., the input signal must undergo modulation before the sounds are finally amplified. The equalizers and tone control knobs too need to undergo the signal modulation stage.

Signal Amplification

It is at this stage that the actual amplification happens. That is why this stage is known as the business stage of a guitar amp. The outgoing signal at this stage is the same as the incoming signal from the modulation stage. The only difference is that the output is of much greater amplitude. In short, the signal amplifier simply and faithfully amplifies the incoming signal.

Output

Output stage is the last stage of a guitar amp. In some amp there is a sub-stage of output driver stage, but some have just a simple output stage. If your guitar amp is not of a good quality, it will just feed the outgoing signal from the amplification stage directly into the loudspeaker. The good quality guitar amps ensure that there is a signal conditioning output stage that matches the output signal to the input specifications of the loud speaker.

A serious guitarist is supposed to have a good working knowledge of guitar amps. If you are knowledgeable, you will always go for a good guitar amp. A good guitar amp makes all the difference to the reliability and predictability of the musical sounds that finally come out of the loudspeaker, when you play your guitar.

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