Principle of acoustic work

A basic sound system consists of a sound source, amplifier, and speaker, all of which are essential as the quality of these components largely determines the overall system quality. The amplifier, as the power source of the sound system, serves as a bridge between the sound source and the speaker.

The working principle of the amplifier is actually quite simple -- it amplifies various sound signals from the sound source to drive the speaker to produce sound. From a technical perspective, the amplifier is like a current modulator, converting alternating current into direct current, then controlled by the sound signals played by the source to transmit currents of different sizes at different frequencies to the speaker, resulting in the speaker producing sounds of corresponding sizes and frequencies. Due to considerations such as power, impedance, distortion, dynamics, as well as different usage ranges and control functions, amplifiers vary in signal processing, circuit design, and production processes. Traditional amplifiers have undergone decades of development without any specific classification until recent years, with the development of audiovisual playback devices and rich film and television software. This has led many sound system manufacturers to design and produce comprehensive amplifiers with different types and technical features based on the sound playback characteristics of real cinemas, known as AV amplifiers, while amplifiers used solely for music appreciation are called pure music amplifiers. According to the current demands of audio consumption, domestic amplifiers have been broadly classified into two categories: pure music amplifiers and home theater AV amplifiers.

Pure music amplifiers emphasize minimal signal distortion in design, faithfully reproducing the scenes, details, performance, recording techniques of music to meet people's best music appreciation requirements, commonly known as Hi-Fi. The requirements for designing and producing pure music amplifiers are extremely strict. A properly matched high-quality pure music amplifier and speakers exhibit high music fidelity, allowing many people to be moved by music. This is why even in the thriving world of home theaters today, many individuals with higher cultural literacy still indulge in pure music sound systems. Additionally, a significant number of people who initially pursued the AV trend and gained some understanding of sound systems have rediscovered the appreciation of Hi-Fi music, further demonstrating the charm of Hi-Fi.

The quality of a pure music amplifier is not solely determined by its technical specifications. It should not solely be judged by how high its power is, how wide its frequency response is, or how low its distortion is, but should particularly focus on its design, production processes, and music resolution. For example, a tube amplifier with relatively low technical specifications might sound more pleasing than many transistor amplifiers. Furthermore, pure music amplifiers especially emphasize the proper pairing with speakers -- a good amplifier for one speaker may not necessarily work well with another. When pairing them, factors such as operating type, impedance characteristics, sensitivity, output current should be considered, and actual listening tests are necessary. Below are two highly cost-effective pure music amplifiers for reference.

'Arjun' (ARCAM) ALPHA 5 amplifier. Those familiar with high-fidelity audio will not be strangers to the British brand 'Arjun'. Though small and unimpressive, even appearing plain and stingy, there was skepticism about whether such a small amplifier could drive high-fidelity speakers or deliver impressive sound quality at a exhibition a few years ago. However, when it confidently drove the 'Tianlang' speakers, everyone was amazed by its outstanding performance despite its small size, and its reputation has been growing. The ALPHA series amplifier is a model introduced after certain improvements on the original DELTA series. It adopts a pure class A structure to reduce signal distortion, with a very simple internal circuit and standard component types, but due to strict manufacturing processes and material quality requirements, the seemingly simple ALPHA series amplifier from Arjun delivers extraordinary sound quality. During actual listening tests, the Arjun ALPHA 5 combined with the 'Tianlanguang' 607 speakers from the same company (sourced from the ALPHA 1 CD machine by Arjun), had near-perfect sound quality. Especially when listening to string instruments and vocals, the ALPHA 5's resolution displayed the strengths of the 'Tianlang' speakers. When playing Vivaldi's 'Four Seasons', every note of the violin was crisp, clear, and pleasing; there was no overpowering sound typical of some amplifiers. Listening to 'Tsai Chin's Old Songs', each breath and pronunciation of the singer was distinctly clear and emotional, completely in harmony with the CD's style. Although the ALPHA 5 has an output power of only 40W per channel at 8Ω, as a genuine British class A amplifier, it has no problems driving most high-end speakers and maintains a clean and precise sound even during musical climaxes, without any muddiness. The ALPHA 5 is priced at around 3000 yuan, combining the advantages of transistor amplifiers and tube amplifiers, offering exceptional value for money.