The most popular panacea for improving sound quali

2022-07-26
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A panacea for improving sound quality

enthusiasts' pursuit of sound quality is endless. In particular, the housing made of thermoplastic ultradur can protect power semiconductors from external factors such as moisture, dust and temperature changes. The front-end amplifier circuit hopes to get a purer music background and better sound quality

To improve the market competitiveness of products

to make a set of power amplifiers with superior sound quality, first of all, there must be a front-end amplifier circuit with superior performance. In order to give full play to its best performance, a front-end amplifier circuit with good modulus measured in this area needs an excellent power supply! Some hi-end class front-end machines use dry batteries for power supply. For example, the battery power supply is used for the front-end su-c7000 of Panasonic's best power amplifier in Japan! However, most of the front circuits of domestic award-winning machines are composed of discrete components. Figure 1 is a noise comparison diagram of three power supply systems: voltage stabilizing IC, discrete voltage stabilizing circuit and battery

here, I would like to introduce the class a parallel voltage stabilizing circuit, which is the most commonly used in domestic award-winning machines, to enthusiasts. The circuit diagram is shown in Figure 2. This circuit is used to supply power to the front stage amplification circuit. The background is very quiet, which makes the low-frequency pressing force better and stronger. The medium and high frequencies become smooth and soft, which greatly improves the music. It feels mild in the subjective sense of hearing, without some cool and harsh feeling. Use this power circuit to rub the machine, Can play an immediate effect, sound quality improvement is very obvious! Because most of the general audio systems use three terminal voltage stabilization or series voltage stabilization, and the better ones use active servo voltage stabilization. The performance of class a parallel voltage stabilization power supply circuit is the closest to that of battery power supply, and the effect is certainly remarkable

analyze the working principle of class a parallel stabilized voltage power supply: 220V mains power is reduced by transformer, rectified by rectifier bridge, filtered by C1 (C2) to remove AC clutter, and then a constant current circuit composed of LM317 and R1 with superior performance (about 160mA, which can drive any pure class a front-stage amplifier circuit. If the current is larger, change the resistance value of R1). The constant current circuit can block the power supply noise, And effectively decouple the interference of the rear stage to the front stage through the power supply. After the constant current, the power supply consists of VT1 (VT realizes the tightening movement of the spring 2), VD1 (VD2), RP1 (RP2), r2-r5, etc. to form a voltage error sampling setting circuit, and controls the base of the regulating tube VT3 (vt4) through R6 (R7), changes the conduction voltage drop of the regulating tube, and uses the shunt current to achieve the purpose of voltage stabilization. The adjusting tube is connected in parallel with the load, and the resistance value is very small

during fabrication, the constant current source (lm317t) and the adjusting pipe shall be installed on a large radiator (note that each pipe and the radiator shall be padded with mica sheet for insulation). The author's choice of components when making: the power supply is the key part of the performance of the previous stage, so it needs to be fully prepared. The 1A rectifier bridge is used for the rectification of the positive and negative power supply, the Japanese famous brands such as Vajra, Elna, ruby and Panasonic are used for the filter capacitor, the Panasonic CBB metallized non inductive capacitor or the Netherlands Thomson MKP capacitor are used for the electrodeless capacitor, and the resistance: the metal film resistance of 2W or above is used for R1, The remaining resistance is the imported 1/4w five color ring metal film resistance. The low-power triode uses the low-noise sound tube a970, and the medium-power triode also uses the sound tube c2073. The potentiometer for adjusting the output voltage cannot be an ordinary product, but must use a precision potentiometer (the market price is yuan/piece). Of course, good components should be equipped with good circuit design: the author uses epoxy glass fiber circuit board and silver plating process

debugging: after correctly welding and connecting the transformer with suitable voltage, power on debugging can be carried out (Note: the voltage of the transformer must be equal to or greater than the voltage required by the front stage sound): use two digital multimeter to connect the output terminals of the positive and negative power supplies respectively to measure their output voltage, and then adjust the precision potentiometer in the positive and negative power supply circuits respectively to stabilize it at the voltage required by the front stage circuit, And make the positive and negative power supply voltages equal. At this time, the front stage can be powered

I believe that clarity, rich sense of hierarchy, high-frequency slender, mellow, sweet and beautiful sound are the sound quality description after the sound supply is changed

you can get instant results by spending tens of yuan. If you are interested, you can tell by trying! (end)

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