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 due to the large number of models and designs. I will explain many of the most common amplifier designs like “tube amps”, “linear amps”, “class-AB” and “class-D” in addition to “class-T amps” to help you understand some of the terms widely used by amplifier manufacturers. This informative guide also needs to enable you to work out which topology is great for your particular application.
To put it simply, the goal of Cayin A88t Mk2 is always to convert a low-power audio signal right into a high-power audio signal. Our prime-power signal is big enough to drive a speaker sufficiently loud. To carry out that, an amp uses several elements which are controlled from the low-power signal to create a large-power signal. These factors vary from tubes, bipolar transistors to FET transistors.
Tube amplifiers used to be common a few decades ago. A tube will be able to control the current flow according to a control voltage which can be connected to the tube. Unfortunately, tube amplifiers use a fairly high amount of distortion. From a technical perspective, tube amplifiers will introduce higher harmonics in to the signal. However, this characteristic of tube amps still makes these popular. Lots of people describe tube amps as having a warm sound versus the cold sound of solid state amps.
Another problem with tube amps, though, will be the low power efficiency. The majority of power which tube amps consume will be dissipated as heat and merely a fraction has been changed into audio power. Also, tubes are usually costly to make. Thus tube amps have mostly been replaced by solid-state amps which I will appear at next.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 existing flow according to a tiny-level signal. Some amps use a feedback mechanism to be able to minimize the harmonic distortion. Class-A amps hold the lowest distortion and usually even the lowest amount of noise for any amplifier architecture. If you want ultra-low distortion then you should take a closer look at class-A models. The main drawback is the fact that similar to tube amps class A amps have suprisingly 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 HIFI RCA Cable. They normally use several transistors to break in the large-level signals into two separate areas, every one of which is often amplified more efficiently. As a result, class-AB amps are usually 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 routinely have higher distortion than class-A amps.
Class-D amps improve on the efficiency of class-AB amps even further using a switching transistor which 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 is being controlled by way of a pulse-width modulator. The switched large-level signal needs to be lowpass filtered so that you can take away the switching signal and recover the audio signal. Because of non-linearities of the pulse-width modulator and also the switching transistor itself, class-D amps by nature have among the highest audio distortion of the audio amplifier.
To solve the situation of high audio distortion, newer Line Magnetic 508ia incorporate feedback. The amplified signal is in contrast to the original low-level signal and errors are corrected. A highly-known architecture which uses this kind of feedback is referred to as “class-T”. Class-T amps or “t amps” achieve audio distortion which compares using the audio distortion of class-A amps while at the same.