The difference between tube power amplifier and transistor power amplifier

           The difference between tube power amplifier and transistor power amplifier

According to the different types of power amplifier tubes, power amplifiers can be divided into tube power amplifiers and transistor power amplifiers. As early as the 1960s, tube power amplifiers had been popular all over the world, but from the 1960s to the 1980s, transistor power amplifiers began to rise gradually. By the 1980s, the number of tube power amplifiers was very small. It has become a symbol of the identity of audio-visual lovers at home and abroad.

What is a tube amplifier

The so-called electronic tube power amplifier refers to a type of power amplifier that uses electronic tubes as power amplifier tubes, also known as amplifiers. The timbre is sweet and warm, the treble is smooth, there is enough air, and it has a kind of sound coloring that quite a few people like. Although the sound details and layers are less, the soft and slightly fuzzy sound is beautiful.

The role of tube amplifiers

The tube power amplifier has relatively strong anti-overload capability. Even if overload occurs, the peak of the music signal is only a little slipperier than the normal waveform, and there will not be much difference in the sound.

The open-loop index of the tube power amplifier is better than that of the transistor amplifier, and it can work stably without adding deep negative feedback or adding a phase compensation capacitor. The open-loop gain of transistor amplifiers is generally large, and its excellent electro-acoustic indicators are achieved by adding a large negative feedback. Therefore, in order to suppress parasitic vibrations, hysteresis compensation is often used, which will cause obvious transients. Distortion affects sound quality.

Advantages and disadvantages of tube amplifiers and transistor amplifiers

Amplifier is a common name for electronic tube machines in Hong Kong and Taiwan. It is known for its feminine sound, while transistor machines are known for their masculinity. The advantage of the transistor machine lies in its high current, wide frequency band, low frequency control, analytical power, layering and brightness when dealing with large scenes, etc. It is superior to the electronic tube machine, but the treble of the electronic tube machine is smoother, has enough air feeling, and has A kind of sound coloration that quite a few people like. Although the sound details and layers are less, the soft and slightly fuzzy sound is beautiful.

The distribution of the harmonic energy of the transistor amplifier is almost the same amount up to the tenth harmonic, and the reduction of the higher harmonic amount is extremely small. The distribution of the harmonic energy of the tube amplifier is that the second harmonic is the strongest, the third harmonic is gradually weakened, and the fourth harmonic is weaker until it disappears. It can be seen that the tube amplifier mainly causes even-numbered second harmonics, which are very pleasing, just like adding rich overtones and beautifying the sound, while among the harmonics generated by transistor amplifiers, the odd-order harmonic components are Quite large, which will cause discomfort to the sense of hearing. In addition, when the amplifier is overloaded and clipping occurs, the waveform of the tube is relatively gentle, while the waveform of the transistor is a trapezoidal flat top, causing serious deterioration of the sound.

Therefore, the timbre of tube amplifiers is generally sweeter and warmer, especially in the mid-frequency range. This amplifier compensates). However, transistors can also be made into amplifiers with high linearity, which have extremely high indicators, and the transmission characteristics of power field effect transistors are very similar to electron tubes, and the distortion characteristics of the fabricated amplifiers are similar to those of electron tubes, and the efficiency is higher.

The internal resistance of the electronic tube is large, and the internal resistance of the transistor is extremely small, so the damping coefficient of the electronic tube amplifier is much lower than that of the transistor amplifier, which is not good for the control ability of the speaker. In addition, tube amplifiers require high-voltage power supplies, low efficiency, high heat, poor shock resistance, large volume, high cost, slow transient response, weak low-frequency and high-frequency upper sections, and short life.

It can be seen that although the electron tube has its unique advantages, it is a misunderstanding that it is better than the transistor, and there is no need to oppose them. Whether the tube machine or the transistor machine is better is a matter of opinion. They each have their own strengths and weaknesses.