LM1875 Multimedia Hi-Fi Amplifier ----- LM1875 Power Amplifier

LM1875 Multimedia Hi-Fi Amplifier, LM1875 Power Amplifier Keywords: lm1875 multimedia Hi-Fi power amplifier LM1875 multimedia Hi-Fi amplifier In recent years, with the popularity of the PC and the price of DVD-ROM, it has been enjoyed with the PC. Secondly, "Golden Ears" and "Silver Ears" have emerged, and the sound quality of the PC is getting higher and higher. But for thousands of high-end active systems, we can only hope in the "shame" in the capsule. So the author DIY has a multimedia active power of Hi-Fi music on the PC. Be This circuit is quite simple, and the sound processing uses a single-chip QS7779 virtual surround circuit of Canada Qsound. Since the circuit has built-in Dolby orientation logic and Dolby digital mixed signal decoder. Not only can the normal stereo signals can be enhanced, but also can decode when playing DVD's Dolby digital signal, then the matrix operation is performed, the virtualization is the two-channel output, and the switch can be switched by the switch. Effect. The effects and sound quality of the circuit are more realistic in the sound community, which is more realistic than those "3D surround surroundings" that are similar. The buffer level of the circuit only uses an OP275 for improving the input and output impedance after the volume potentiometer. This operation is used here to enhance the driving force on the end level, which is reduced, and the interaction between the column is in a high motion. The last level of power is selected by the world-famous LM1876TF, which is from the US NS, the conversion rate of 18μV / ms, the signal-to-noise Big 92dB, and its quiescent current is only 4mA. Due to integrating two fully independent channels, a piece of heat sink is shared, ensuring that the circuit has a high degree of separation and the same temperature characteristics. The IC output power is 25W, which is better in a small multimedia active system in the listening environment. The number of peripheral components of this amplifier is small, only 8 per channel, so it is easy to make the board and transform existing multimedia speakers. Be Production points: resistance should be used for a warm metal film resistance, and the coupling, negative feedback and decoupling capacitance should be used in each of the coupling, negative feedback and decoupling capacitance. The transformer uses 200W high-quality ring cattle, secondary each as two sets of double 18V output, a set of small current, and another set of large currents. Filter capacitors at the power supply should be used in parallel use of 2200μF / 50V in RubyCon. This will ensure strong power under great dynamic. Capacitors C14, C21, C16, C23, C18, C42, C37, C38, C40, C27, C31, C44, C45 were WiMA0.1 μF / 63V. Three-end regulation uses general LM7815, LM7915 and LM7805. The sound processing section can be used for commercially available products, and the radiator of the LM1876 power block should be large enough. All components are installed and connected correctly, after error, the power is turned on. Be Actual listening: Connect the innovative SB-Live sound card on the PC, the speaker is self-made using the two-point small bookshelf box with Hiwei 6.5-inch bass and SS1 + treble. First, the sound switch is placed in straight, and "in that distant place", the performance of the wind blowing the wind blows from the electronic synthesizer, the violin is clear, and the tone is rich. The high-frequency "嚓嚓" sound of the triangular iron is buckled, clear and pleasant, and the whole sound area is open. Place the sound switch in the enhancement block, put a "future warrior sequel", play the software with PowerDVD, set the sound effect as "stereo", and many explosive scenes in this dish are surged, magnificent. The strong air flow of low frequencies is straightforward and amplifier is not "feet soft", and the bullets of various guns move move in the sense and positioning. There is also a good performance for the game sound effect. When playing "Resident Evil", the background effect sounds, especially the sound of various "ghosts" moving in different directions, with the bleak music, better creating one A creepy atmosphere. This high performance is exchanged for more than two hundred yuan, and it is true that the value is exceeded.