All about Guitar Amplifiers

Guitar amplifiers are electronic amplifiers designed to be used with electronic musical instruments, such as an electric guitar.
Guitar amplifiers are mainly made in two major forms. The combination (or combo) amplifier has the amplifier head and guitar speakers in a single unit. The amplifier head or amp head contains the electronic circuitry constituting the preamp, built in effects processing, and power amplifier.
In the second form, the amplifier head is detached from the speakers, and joined by cables. The separate amplifier is known as an amplifier head, and is normally located on top of one or more loudspeaker enclosures. This separate amplifier head when placed on top of a guitar speaker enclosure or guitar speaker cabinet forms an amplifier stack or amp stack.
Instrument amplifiers Types
An extensive range of instrument amplifiers can now be used with the electrical guitar. Some are for general purpose and some designed for specific instruments and even for a definite sound. These comprise: Traditional guitar amplifiers which generate a clean, warm sound a sharp treble roll off at 5 kHz or less and bass roll off at 60 to 100 Hz. It has presets with built in reverb and tremolo (vibrato) units.
These types are often used by traditional rock, blues, and country musicians. Chances are that when on higher volume level the sound can get distorted. So to counter higher end bass amplifiers at times include compressor or limiter features, and an XLR DI output to patch the bass signal directly into a mixing board. To keep the bass amplifiers cool they are often provided with external metal heat sinks or fans.
Keyboard amplifiers, have a low distortion rate and also to make things easy for its functioning it has a simple onboard mixer. This assists the keyboardists to control the tone and level of several keyboards.
Acoustic guitar amplifiers are intended solely to produce a clean, transparent, acoustic sound when being used with acoustic instruments with built in transducer pickups and microphones.
In addition to a 1 by 4 inch input jack, some instrument amplifiers bear an additional input jack for inserting microphone. This is known easily as it will use a three pin XLR connector. Conversely, phantom power, which is not a necessary for lower end amplifiers, is often provided with the high end versions, so that musicians can use condenser microphones.
Vacuum tube guitar amplifier circuit is rather uncomplicated. Two triodes are used in the preamplifier section for obtaining a high signal level to implement any tone controls and drive the following sections. Two more triodes split the phase of the signal and drive the final pentode or beam tetrode (kinkless tetrodes) tubes of the push pull power amplifier stage.
Solid state guitar amplifiers commonly have the quickest response time, even more so than modeling amps. Tubes tend to create warm overdrive sounds instead of cutting the peaked signal off. They more or less pull the peaked audio information back (like natural compression) which creates a fuzzy overdrive sound.
Modeling guitar amplifiers are used to simulate sounds of well known cabinets, guitar amps, and effects. Digital processing is done to obtain this, although there are prevalence analog modeling amps as well, like the Tech 21 Sansamp. Modeling amps characteristically output a wide range of tones and effects, and offers cabinet simulation, which aids the recording without a microphone.