Guitar amplifiers usually have several signaling pathways (channels) with different sound characteristics. Clean channels only have a volume adjuster; sometimes it is even combined with a tone setting. Jazz guitar amplifiers channels with more distortion usually has a gain adjuster that affects the strength of distortion degree, coupled with a volume adjuster for the output volume. The channels can be selected by pressing a button on the amplifier. Combos incorporate one or more loudspeakers mounted in a common housing.
Guitar speakers typically have pronounced resonances; the speakers are hung tough and are less attenuated by the high source resistance of tube amplifiers. In contrast, hi-fi speakers convey music signals but do not have their own sound. The resonance behavior of the often open-back wooden housing is another reason for the lower attenuation and the warm sound with pronounced mid-shift. The output stages of tube guitar amplifiers operate mainly in AB mode, that is, it uses one tube to amplify the positive or negative half-wave (push-pull).
The signal flow and arrangement of components and adjusting elements becomes clear. The individual components of a guitar amp are the input (signal input), mostly realized by a connection with a 6.35-mm mono jack, preamp with volume control, tone control (equalizer) to boost or cut individual frequency ranges (bass, middle, treble and linear distortion), output amplifier, speaker system and power supply (PSU).
For example, the speaker system usually consists of eight and 15-inch speakers so is a typical Marshallbox with 4 speakers, each equipped with 12-inch and loaded with 100 to over 400 watts RMS power. In many devices, a so-called reverb (spring reverb) is installed for generating artificial reverberation.
On the other hand, there are amplifiers that combine the sound characteristics of the A-operation by parallel connection of power tubes with higher performance. A disadvantage of the A operation is the constant, relatively high power consumption. Swapping the power tube changes sound behavior significantly. Often, the power tubes are not re-measured.
The first tube amps from the 1950s could hardly control the precursors, but the distortion was achieved by setting the amp as loud as possible. This means the power tubes were overridden and the transformer went into saturation. This is what influences the sound of guitarists such as Jimi Hendrix and Alvin Lee (Ten Years After). Technically spoken messages are added to the signal in single-ended tube, which increases even-numbered harmonics (overtones) and the signal is increasingly soft (soft clipping).
The auditory impression of distorting tube amp is described as dense, loud, rough and groovy. This sound is important in all areas of rock music and a typical guitar sound is a vital part of music styles of hard rock and heavy metal. This is probably due to the well-configured override behavior and the higher internal resistance.
If this is not desired, the loudspeaker can employ a resistor network connected upstream, which converts the major part of output signal feeding only a fraction of the output power (power soak). Alternatively, it performs a power reduction during the output stage (for example, by reducing the operating voltage of tubes) to deliver the desired result. In all cases, however, it must be remembered that this inevitably leads to decline of overall volume of nonlinear distortions of the loudspeaker, which also contribute to distortion on the output stage.
Guitar speakers typically have pronounced resonances; the speakers are hung tough and are less attenuated by the high source resistance of tube amplifiers. In contrast, hi-fi speakers convey music signals but do not have their own sound. The resonance behavior of the often open-back wooden housing is another reason for the lower attenuation and the warm sound with pronounced mid-shift. The output stages of tube guitar amplifiers operate mainly in AB mode, that is, it uses one tube to amplify the positive or negative half-wave (push-pull).
The signal flow and arrangement of components and adjusting elements becomes clear. The individual components of a guitar amp are the input (signal input), mostly realized by a connection with a 6.35-mm mono jack, preamp with volume control, tone control (equalizer) to boost or cut individual frequency ranges (bass, middle, treble and linear distortion), output amplifier, speaker system and power supply (PSU).
For example, the speaker system usually consists of eight and 15-inch speakers so is a typical Marshallbox with 4 speakers, each equipped with 12-inch and loaded with 100 to over 400 watts RMS power. In many devices, a so-called reverb (spring reverb) is installed for generating artificial reverberation.
On the other hand, there are amplifiers that combine the sound characteristics of the A-operation by parallel connection of power tubes with higher performance. A disadvantage of the A operation is the constant, relatively high power consumption. Swapping the power tube changes sound behavior significantly. Often, the power tubes are not re-measured.
The first tube amps from the 1950s could hardly control the precursors, but the distortion was achieved by setting the amp as loud as possible. This means the power tubes were overridden and the transformer went into saturation. This is what influences the sound of guitarists such as Jimi Hendrix and Alvin Lee (Ten Years After). Technically spoken messages are added to the signal in single-ended tube, which increases even-numbered harmonics (overtones) and the signal is increasingly soft (soft clipping).
The auditory impression of distorting tube amp is described as dense, loud, rough and groovy. This sound is important in all areas of rock music and a typical guitar sound is a vital part of music styles of hard rock and heavy metal. This is probably due to the well-configured override behavior and the higher internal resistance.
If this is not desired, the loudspeaker can employ a resistor network connected upstream, which converts the major part of output signal feeding only a fraction of the output power (power soak). Alternatively, it performs a power reduction during the output stage (for example, by reducing the operating voltage of tubes) to deliver the desired result. In all cases, however, it must be remembered that this inevitably leads to decline of overall volume of nonlinear distortions of the loudspeaker, which also contribute to distortion on the output stage.
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