Distributed component amplifier with 2SA2151 and 2SC6100, 2SA2151 + 2SC6100 AMPLIFIER
Keywords: discrete component amplifier with 2SA2151 and 2SC6100
The 2SA2151 and 2SC6100 is a new audio amplifier specialized high-power pair in Japan's "Three Reclamation" companies. The author is fortunate to get the 2SA2151 and 2SC6100 two pairs of the manufacturer. According to the technical parameters provided by the manufacturer and some of the experience of some monthly production amplifiers, it has created an amplifier that is very suitable for home use, and the circuit provides the following for your reference.
Circuit Selection Scenario The author's listener is 21 square meters, and the speaker is self-made LS3 / 5A two-degree frequency monitor listening speaker. Because there is a chance to contact various audio equipment, it has been determined to make a variety of sound comparable amplifiers. Most of the voltage amplifies the form of operational amplifier, the transistor is divided into the form, the electronic tube, and the switch is switched to compare. The final stage is used in the form of 0dB purel. There is no negative feedback form, and the circuit is shown in Figure 1. This kind of circuit form is based primarily on the following considerations: 1. The form of purel A-class work can basically eliminate the distortion and switch distortion. These two distortion cannot be overcome. 2. Using no large loop negative feedback form, the transient intermodulation distortion and the intermodulation distortion caused by loop negative feedback can be eliminated. Both distortions are dynamic indicators, quantitative measurement, these two distortion methods are very troublesome, so the whole machine products do not have these two distorted technical indicators. Transient intermodulation distortion has greatly affected whether playback sound quality naturally, usually does not pay attention to this indicator. Interpolation intermodulation distortion is a new dynamic distortion that is generated by the loop negative feedback when the speaker is working. When the intermodulation of the interface is serious, the voice of the playback will be turbid, all of all the amplifiers of the large rings negative feedback have this problem, but the degree is different. 3,0db purel, no negative feedback power is no voltage gain, and the performance of the voltage amplifies is a test. Since there is no other indicators such as negative feedback loops, harmonic distortion, damping factors, it is guaranteed by circuit itself and component quality. Be
Compound magnification of component mounting and debugging is composed of two levels, and the power tube at level 1 is magnified, and the primary current output is performed at a high power tube. Figure 1 Circuit In order to adapt to different voltage amplification output current, the current amplifier uses the Dal Ton structure to make small currents to meet the needs of output rated power. Figure 1 Circuit purel 甲 output power is 25W (8Ω load), static current 1.25a, so that the static tube consumption of each of the power tubes is 31.25W, and the total static power consumption of 4 power tubes is 125W. When the circuit is made, the printed circuit board can be assembled, or the form of weld is also assembled directly on the heat sink. The area of the radiator should be met when assembled, generally use a radiator similar to the 200W finished machine. When assembling the printed circuit board, the constant voltage bias adjusting tube 8050 should be close to the heat sink to perform temperature compensation, and two medium power pipes per arm should be back to the back tight sticker to ensure the heat balance, such as the soldering, all transistors all transistors Announced on the heat sink, the power supply is directly connected to the high power tube C pole, and the adjustable resistance should be used to ensure the accuracy and safety of the adjustment. The input capacitor has a large impact on the sound, and the brand can be selected according to its own preferences. All transistors should be paired. After the assembly is equipped, the debug is adjustable. First adjust the 10K adjustable resistance to lower the output-side DC voltage below 10 mV. If the DC voltage cannot be adjusted to 10 mV, it means that the palatability of the transistor is not good, and the replacement should be replaced, and the adjustment of the static current is adjusted. Adjusting 5K adjustable resistance reduces the DC voltage at both ends of the high-power tube emitter resistance (0.22 Ω / 5W) to 275mV, at which time the quiescent current is 1.25A, allow the amplifier to stand in this state 1 hour to measure the median DC Voltage and quiescent current values, if it does not match. After adjusting the power, the power is completed, and you can work if you have completed the production.
Voltage amplification elevation selection and assembly Figure 2 is a transistor voltage amplifier, which selects a pre-predecessor amplifier circuit of the famous "Mant Shi" PM. When the end-level amplifier has a rated output of 25W, the voltage amplifier should provide no loss of 15V, the original circuit is used as the pre-magnitude of the amplifier, and the voltage amplifier is only 8.5 times, which cannot meet the needs, this circuit will The voltage magnification is changed to 22 times to meet the needs of the end. After the drawing is installed, the 470Ω adjustable resistance is adjusted to reduce the static current of D669 and B649 to 20 mA, which makes it working in a state. Figure 3 is a voltage amplifying stage using double-acting composition, which is mainly to appreciate the op amp and sound quality of different grades. Since the maximum output voltage of the op amp is only 13V, this circuit is used to push the maximum power at the end level. Only 20W, the assembly position is plated with a gold-plated socket to replace different op amps. Figure 4 is a large-scale electrical pressure amplifier, and the circuit references the "Matis" circuit of the world, and has made some changes in the power supply voltage and magnification for adaptation of the final level. The tone of this circuit is quite sweet, and it is equally equipped with the pureroa final combination. Circuit assembly is easy, no need to debug a load. The above three voltage amplifications should be used to use high-quality components, especially the coupling capacitance at all levels, should be selected. The final working voltage of this unit is integrated in a state of 1.25A, and does not easily improve the working voltage of the last level power tube in order to increase the output power. If the speaker impedance is 4Ω, the pureroa power It will drop to 12.5W, and the A-class power will increase to about 60W. Due to the end-level power vessel does not enter the loop negative feedback network, the distortion will be significantly increased after the operating point enters the B-state, so the final level of power should be re-adjusted The static current and operating voltage of the tube are in the 4Ω load, there is a 25W pureroa power output quiescent current should be adjusted to 1.77A, and the operating voltage should be ± 17V; at this time, the single power tube is still about 30W. This power can fully meet the needs in the home playback state, push 10-inch triple frequency floor-style speaker is more than enough, this is the difference between the pureroa and the use of B-class amplifier, interested readers can try.
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