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 hard to pick an amplifier given the multitude of models and styles. I will explain some of the most common amplifier designs including “tube amps”, “linear amps”, “class-AB” and “class-D” along with “class-T amps” to help you understand some of the terms frequently used by amplifier manufacturers. The following information also needs to enable you to work out which topology is great for your particular application.
In other words, the purpose of Cayin Audio would be to convert a low-power audio signal right into a high-power audio signal. The top-power signal is large enough to drive a speaker sufficiently loud. In order to do that, an amp uses a number of elements which are controlled by the low-power signal to create a big-power signal. These factors range from tubes, bipolar transistors to FET transistors.
Tube amplifiers used to be common a few decades ago. A tube is able to control the current flow in accordance with a control voltage which can be connected to the tube. Unfortunately, tube amplifiers possess a fairly high quantity of distortion. Technically speaking, tube amplifiers will introduce higher harmonics in to the signal. However, this characteristic 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 problem with tube amps, though, is the low power efficiency. Nearly all power which tube amps consume has been dissipated as heat and only a fraction has been changed into audio power. Also, tubes are very costly to make. Thus tube amps have mostly been replaced by solid-state amps which I will look at next.
Solid state amps replace the tube with semiconductor elements, typically bipolar transistors or FETs. The earliest form of solid-state amps is known as class-A amps. In class-A amps a transistor controls the existing flow according to a small-level signal. Some amps utilize a feedback mechanism in order to minimize the harmonic distortion. Class-A amps possess the lowest distortion and usually also the lowest quantity of noise for any amplifier architecture. If you want ultra-low distortion then you should take a closer look at class-A models. The key drawback is the fact much like tube amps class A amps have suprisingly low efficiency. Consequently these amps require large heat sinks to dissipate the wasted energy and are usually fairly bulky.
Class-AB amps improve on the efficiency of XLR Cable. They utilize a series of transistors to get rid of up the large-level signals into two separate areas, every one of which may be amplified better. As such, class-AB amps are often smaller compared to class-A amps. However, this topology adds some non-linearity or distortion in the area where the 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 more using a switching transistor which is constantly being switched on or off. Thereby this switching stage hardly dissipates any power and phczif the energy efficiency of class-D amps usually exceeds 90%. The switching transistor will be controlled with a pulse-width modulator. The switched large-level signal needs to be lowpass filtered so that you can remove the switching signal and recover the audio signal. As a result of non-linearities in the pulse-width modulator and the switching transistor itself, class-D amps naturally have among the highest audio distortion for any audio amplifier.
To fix the issue of high audio distortion, newer Line Magnetic 518ia incorporate feedback. The amplified signal is in contrast to the first low-level signal and errors are corrected. A well-known architecture which uses this kind 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 on the same.