In real life, most commonly used power amplifiers combine pre amplifiers and post amplifiers that amplify large and small signals into a single chassis. This type of power amplifier is commonly referred to as a "combined power amplifier". The advantage of a combined power amplifier is its convenience in use and superior product performance.
However, this combined power amplifier has some inherent drawbacks, among which the most difficult to overcome is the mutual interference problem between the front and rear stages. In order to solve this problem, the front stage amplifier and rear stage amplifier were designed in two separate cases, resulting in a pure rear stage amplifier. According to data, the vast majority of pure rear stage power amplifiers have a dual channel structure, but this structure makes it difficult to solve the problem of mutual interference between the two channels. In order to solve the signal interference between two channels, a single channel pure post amplifier that separates the two channels has emerged. The main performance indicators of a mono amplifier include output power, frequency response, distortion, signal-to-noise ratio, output impedance, damping coefficient, etc. The weak signal from the sound source or preamplifier amplifies, pushing the speaker to play.
The main significance of dividing power amplifiers into functional blocks is to improve the performance of the amplifier, rather than pursuing this form of separation. If only formal separation is achieved, although it can solve the problem of mutual interference, other parameters have not been significantly improved, then this separation is still very limited in improving the overall performance of the power amplifier.
Power amplifiers can be divided into transistors and electronic tubes, while the front stage can also be divided into transistors and electronic tubes. For Audiophile and music lovers, there are a variety of combination forms in selecting the front and rear levels, and different combination forms have different sound effects, which makes users have more space to choose.
The front stage connected to the pure rear stage amplifier has a significant impact on the overall quality of the audio system. Firstly, it must have a certain level of performance, otherwise the advantages of pure rear stage or mono channel will not be fully realized, and it may even highlight the "problem" of a low-quality front stage, making the overall sound effect even less ideal. Furthermore, different front and rear stages, combined with their different timbre characteristics, allow users to choose different combinations of power amplifiers based on their personal preferences.
It is not difficult to find that many audio and music enthusiasts like to use the combination method of "gallbladder front, stone back" (i.e. electronic tube front stage, transistor rear stage), believing that this combination not only leverages the characteristics of high power output and good transient response of the transistor rear stage, but also appreciates the sweet and mellow tone of the electronic tube front stage. However, this combination is not a golden rule, as each specific front stage and rear stage have their own characteristics, The preference for sound quality varies from person to person, and users can find their favorite sound combination based on specific usage situations, thereby obtaining a better sound experience.