Audio amplifiers are at the very heart of every home theater system. As the quality and output power requirements of today’s loudspeakers increase, so do the demands of audio amps. It is difficult to pick an amplifier because of the multitude of models and fashions. I will explain many of the most common amplifier designs such as “tube amps”, “linear amps”, “class-AB” and “class-D” along with “class-T amps” to help you understand some of the terms commonly used by amplifier manufacturers. This guide must also assist you to work out which topology is ideal for your particular application.
To put it simply, the objective of Cayin A88t Mk2 would be to convert a minimal-power audio signal right into a high-power audio signal. The top-power signal is large enough to drive a speaker sufficiently loud. To carry out that, an amp uses a number of elements that are controlled through the low-power signal to create a sizable-power signal. These components vary from tubes, bipolar transistors to FET transistors.
Tube amplifiers used to be common a couple of decades ago. A tube will be able to control the present flow based on a control voltage which can be attached to the tube. Unfortunately, tube amplifiers possess a fairly high quantity of distortion. From a technical perspective, tube amplifiers will introduce higher harmonics in to the signal. However, this sign of tube amps still makes these popular. Many people describe tube amps as using a warm sound versus the cold sound of solid state amps.
Another drawback of tube amps, though, is definitely the low power efficiency. Nearly all power which tube amps consume will be dissipated as heat and only a fraction has been converted into audio power. Also, tubes are very costly to make. Thus tube amps have mostly been replaced by solid-state amps which I can look at next.
Solid state amps replace the tube with semiconductor elements, typically bipolar transistors or FETs. The earliest type of solid-state amps is called class-A amps. In class-A amps a transistor controls the present flow according to a little-level signal. Some amps use a feedback mechanism in order to minimize the harmonic distortion. Class-A amps hold the lowest distortion and in most cases even the lowest amount of noise for any amplifier architecture. If you want ultra-low distortion then you definitely should take a closer look at class-A models. The main drawback is that similar to tube amps class A amps have very low efficiency. Because of this these amps require large heat sinks to dissipate the wasted energy and are usually fairly bulky.
Class-AB amps improve on the efficiency of Speaker Cable. They normally use several transistors to interrupt the large-level signals into two separate areas, each of which is often amplified more effectively. Therefore, class-AB amps are often small compared to class-A amps. However, this topology adds some non-linearity or distortion in the region where signal switches between those areas. Therefore class-AB amps typically have higher distortion than class-A amps.
Class-D amps improve on the efficiency of class-AB amps even further using a switching transistor that is constantly being switched on or off. Thereby this switching stage hardly dissipates any power and phczif the power efficiency of class-D amps usually exceeds 90%. The switching transistor will be controlled with a pulse-width modulator. The switched large-level signal has to be lowpass filtered to be able to eliminate the switching signal and recover the audio signal. As a result of non-linearities in the pulse-width modulator and also the switching transistor itself, class-D amps naturally have between the highest audio distortion of any audio amplifier.
To fix the problem of high audio distortion, newer Line Magnetic 218ia incorporate feedback. The amplified signal is in contrast to the initial low-level signal and errors are corrected. A well-known architecture which utilizes this sort of feedback is called “class-T”. Class-T amps or “t amps” achieve audio distortion which compares with the audio distortion of class-A amps while in the same.