Tube Amps are one of the most popular types of digital audio amplifiers. Tube amps can run on three types of semiconductor transistors, the most popular being bipolar. There are several different classifications for these, the most common being Class A, B and C. Class A is the cheapest of the three; it has the least amount of distortion and can overheat quickly. Class B offers good sound quality but is likely to become outdated very soon as the semiconductor technology on the market grows.
A solid-state amplifier or valve amp is a sort of digital amplifier which uses vacuum tubes to boost the signal or frequency. Tube amps were usually replaced by solid-state amplifiers in the early 1960's and for low to medium frequencies below 100 MHz, solid-state amplifiers were more often replaced by cheap tube amps in the later years. Solid-state amps are much smaller than their tube counterparts, and most don't have any sort of foot control. Some operate with only their chassis-mounted valves. Tube amps use two or more vacuum tubes that are arranged in parallel, so that they form a solid wave, rather than a series of semi-transparent tubes.
Although solid-state amps do offer some advantages over tube amps in terms of price and size, they also have several disadvantages. The main disadvantage of using tubes in tube amps is the fact that they take up more space. They are also limited in their ability to reproduce high frequency sounds. Modern solid-state amps are quite small in size, but they still are not as small as some other popular home theater devices.
A power tube is used to boost the voltage across a speaker, typically from ten to fifteen volts. A DC source is connected between the speaker's positive and negative terminals, and this creates a temporary electric field that induces a low-level of current in the speaker's power wire. This induced current flows through a speaker's speaker side plate, and then through its joint speaker side plate cap.
When solid-state amps are run, the current that passes through the speaker's terminals converts it to acoustic vibration. These types of amps are generally used to replace standard speakers. Many vintage rock and heavy metal musicians use them to create distortion-free sounds at their live shows. The sound produced by these tubes is very distorted, yet the distortion is produced using only one source, so it is called "single-stage." Some guitarists also use them to create flanging effects on their guitars.
Power tube amplifiers are also commonly used as "overdrive" circuits in basses and guitars. Basically, the clipping diode in a power tube amp gives current to the filament; the filament will then heat up and burn out. Because of this, power tubes can have a brighter sound than solid-state amps. However, they are not recommended for creating loud lead tones.
Turntables, which utilize two or more power tubes in their design, give a complex sound when they are run at high frequencies. There are two different kinds of turntables: direct-vent (DV) and indirect-vent (IV). While both use the concept of an open collector, the only difference is the manner in which the air is supplied to the amp. A DC-powered VSTC is capable of running at high volumes even when just one power tube is active. On the other hand, an IV-powered system contains one preamp with a built-in valve switch that allows the user to control his or her intake of air.
Any type of amp can be replaced using a tube diagram. You may need to modify the existing schematic in order to make the modifications you need. But if you are replacing an existing tube, it would be worth the time it takes to draw the necessary tube diagrams. This will save you time and money.