Author: Qin Fucheng
Here, the author recommends several easy to make, easy to debug, high success rate, high-cost strategic stone power discharge circuit.
First introduce the post-casage circuit, the principle is shown in Figure 1.
This power discharge pressure is made of blue ship production and uses a multi-year voltage amplification module LIAV. The module circuit references the European and American business opportunities, which use the source-base difference amplification circuit, that is, commonly known as "Owman Circuit". Usually the first stage of the active amplifier is more designed to 1 mA, a higher sex ratio can be obtained. In general, the current is small, the signal-to-noise is relatively high, but the sound is hard. The current is large, the sound is relatively warm, but the signal-to-noise ratio has deteriorated. In actual production, [Jav module internal first level uses K389 / J109 or K170 / J74 field effect tube input, the input stage is still 3mA ~ 4mA, and its signal to noise ratio is also high.
Since the voltage amplification module circuit is fixed, the entire power amplifier circuit is assembled is quite easy.
Most of the current is amplified by the field effect tube, that is, the use of Toshiba power tube K2013 / J313 pushes the Hitachi high power tube K1058 / J162 for electricity. In order to improve low-frequency response, the circuit uses passive servo feedback. The amplifier is designed as a large-loop feedback circuit, and the enthusiast can be easily changed to no large loop feedback amplifier. The sound quality is small and different (printed, the enthusiasts only need to disconnect the C, D, C, C, E Two points can be connected to a transpline). The entire circuit has no special, adjusting 2kΩ multi-circle precision potentiometers, the end level can get the desired quiescent current.
Since the Hitachi K214 / J77 is pushed, the quiescent current is more warm in 50mA to 100mA, but this is a large amount of heat in the pipe, so the power tube is used in Toshiba's K2013 / J313 insulation package, the tube, whether it is in large current Or small current state, the sound is balanced, the sound is warm.
立 K1058 / J162 static current is 100mA ~ 200mA, which is full, with human love, high frequency fiber. Increase current, static current 200mA ~ 400mA, the sound quality changes are not obvious, and the power pipe is large. Comprehensive consideration, K1058 / J162's static current is better than 200mA.
Of course, this power amplifier circuit pre-throttle can also be replaced with other triodes, such as C2073 / A940, C517L / A1930, etc., also available to high power tubes such as C5200 / A1943, C5198 / A194L. At this point, the line also sounds well, but the tone has been turned from the music type, and it is known that the price of a pair of K1058 / J162 is equivalent to the price of 3 times C5200J / A1943.
Need to note: Hitachi K214 / J77, K1058 / J162 is arranged to g, d, s, and Toshiba K2013 / J313, K1529 / J200 is arranged to g, s, d, assembly, ie Restable. Specific commissioning can refer to "Easy Make Soundtrans" One article, you can work in the "Electronic Newspaper" website WWW.
Additionally, the entire power amplifier circuit can also be used as a voltage excitation portion of a purellravailable amplifier circuit. The author designed a 0DB power amplifier plate for the enthusiasm that likes to make purel A power amplifiers. The ODB board is only current gain, no voltage gain, and frequency is 0Hz ~ 500kHz.
The printed plate is designed with a field effect tube (K1058 / J162 or K1529 / J200), and the schematic diagram is shown in Figure 2. The board is self-contained, and the voltage of VL, V2 can be changed to change the static current of the final power tube and the midpoint potential.
In theory, the amplification circuit that can be adjointed with the voltage gain can be connected (can be a stone circuit circuit, or a biliary circuit). During actual production, the output impedance of the pre-stage circuit is required as low as possible. Obviously the printed board is designed to be 6-to-field effect tube, and it is not necessarily required to assemble 6 pairs of high power tubes, and the enthusiast can be assembled according to the actual situation. Of course, the power tube is multi-pair in parallel to reduce the output impedance, but the cost will increase much.
The ODB power amplifier plate is wider, and ± 30V ~ ± 80V can be eligible, and the user can select the power supply voltage according to the required power.
If the output point of A and B is connected to each 0DB power amplifier plate, it can also be high, the bass independent power division, as shown in FIG. This can reduce the pairing difficulty in the use of the field effect tube, and improve the sound quality, and can be two. The ODB amplifier plate is also the easiest and absolute success in the army army. It can be described as the most proud "Universal Availability Power Discharge Solar".
The power supply schematic of the amplifier is shown in Figure 4, which uses a simple bridge rectification and multi-stage filtering. High power resistance should choose O.22Ω / 5W non-sense resistance, filter capacitor selection British "Novartis"
NOVER Electrolysis 10000μF / 50V or 10000μF / 63V, the capacitance is high, but the sound is more concentrated, and the sound quality is not multi-daily ordinary electrolytic capacitor. Power supply decoupling capacitor selection ELNA Silmic 220μF / 63V, signal output coupling selects a domestic high-quality MKP capacitor.
The power amplifier voltage amplifier can be powered from the power supply, and a set of power supplies can also be shared with current amplification.
As for the protection circuit, the reader can be made with the μPCI237 special chip or other universal protection circuit.
The above circuits can be successfully installed, and the sound quality will never be disappointed.
The author is equipped with a few agad circuits, such as the pre-class of the NE5532, 0P2604 and other subordinates, but always feel that the mid-low-priced Hi-Fi equipment is used to use the stranger than the stone machine The pre-level can be more expensive.
In fact, the pre-stage is more important than the post. Some Hi-End front-rear grades, the prior price prices are 2 or 3 times the post-level price. As the saying goes, the pre-level sound, the post-level drainage is also the importance of the forefront.
In front-level, the author has also imitated some famous lines, such as Macus, Maranti Seven, Hetao, Jadis, and other DIY. Various circuit tones have their own characteristics, but always feel that JADIS JP-200 timeline circuit is characterized, with tone balance, real and strong music infectivity.
Imitation, the author also never believes that the DIY timer level of several hundred or two thousand yuan can reach or approach the price of tens of thousands of yuan. As long as the sound of the original machine seven eight% is quite good. The key is that we can get some inspirations from the imitation list to draw the essence of the business.
I remember that the "Electronic News" before 2000 has several discussions on the power amplifier need to increase the tone circuit, and published many excellent stone machine front-level circuits with tone function. Later, rarely mentioned the tone circuit, and the enthusiasts saved the tone circuit in the production. To find the sound of "original original". In fact, "the original smell" is relatively, and it is endally in ear test.
The author has installed some pure lines to enlarge the timid stage, always feel that it is relatively high to get a sound, and the sound source and listening environment requirements are relatively high. For most musical enthusiasts, listening environment and source may not be ideal, then the pre-pre-order increased tone circuit can be said to be greater than the disadvantage, but only high, the bass adjustment range cannot be too wide, otherwise the signal phase distortion is large.
The following is the two kinds of timid first-made two-game line production. Figure 5 is not quite, using an electronic pipe such as 6N8 or 6N3, adds a level attenuated tone circuit, after which the electronic pipe is used to zoom in, of which the line can be used to refer to the JADIS JP200 daring front line, which is reduced. Internal resistance, increase the reaction rate, using the tube and used.
The tone portion does not adopt a universal amphipido-tone circuit, the author feels that the 500kΩ, LMΩ double potentiometer used in the amplifier tone circuit and the high pressure small capacitance capacitance used (10nf below) are difficult, and the components are large, so Produce high quality general equipment.
Figure 6 The circuit is similar to that of Figure 5, but its line is placed in front of the US poetry in front, and its important feature is to add an impedance converter after each level is enlarged.
From the perspective of signal-to-noise ratio, the above two kinds of timid volume potentiors are placed at the end. During the production process, it is recommended to use a double potentiometer.
The volume control needs to be left, right channel independent adjustment, that is, two single or put the two double potentiometers as a single potentiometer. This will save a balanced adjustment potentiometer, at this time, even if you use a domestic high-quality potentiometer, in addition to the need for twice, it is not used to it.
From some kind-of-level business line, most of them use large loop overhead negative feedback, perhaps their success. If you use other electronic tubes to change the imitation, the optimum value of the circuit parameters is obtained from the practice. If the design is properly designed, the single-stage amplifying circuit also can make a sound.
Figure 7 is all the daring front-level programs produced by domestic 6N8P, and the Impact Circuit author does not give a specific circuit. According to the fabrication process, according to the love, it can use a negative feedback tone circuit, and the attenuation type tone circuit is also available. Volume / tone circuit, such as M62446, PT2314, and some excellent BBE circuitry.
These chips are mostly used in multi-channel sound systems. If some functions are discarded, they are used as fever production, and they are not tasted for two channels HI-FI audio systems. This sound source selection, volume, and high and low adjustment can have remote control, the sound quality can also reach the Hi-Fi level, "gallstone mixed-blood pre-grade" tone is more charming. Some of the commonly used pitch circuits such as LML036, LM4610, TDAL524, which are considered from sound quality and signal-to-noise ratio, if they are used herein. As for the power part, the enthusiast has a high trick, and the author did not give a specific circuit. The reader can inquire about the "Easy Make the Sound Delicate" article in 2002, "Electronic News" website www.netdzb.com.
What is more confused by enthusiasts? Is the tube filament power supply better or DC better? Each of them has a characteristic, and the sound quality is extremely small.
The author believes that if the grid voltage is relatively stable or the home is equipped with a 220V AC regulator, the tube can be connected in parallel, series, etc., the filament can be powered by 6.3V or 12.6V, and the rectification, filter portion It can be described as a cost savings. If the user's grid voltage changes large or not finds a suitable amiosal transformer and the appropriate voltage parameters, then other transformers can be replaced by rectification, filtering, and regulating appropriate voltages. For beginners, the filaments DC regulatory power supply is greater than the disadvantage.
The above lines, the enthusiasts can be made of wire board or shed welding. According to the size of the chassis, the author is actually used to combine both the circuit board and the shed welding.
The author never rejects some imported fever and fever capacitors, but the price is several times more than ten times the price of domestic brands, and the author is also selected. The use of imported devices is not discussed herein.
When the author made the above courage, because some foreign brand electrolytic capacitors were used for a while, and the rest were used. For example, domestic tubes, domestic MKP capacitors. As we all know, the domestic electronic tube is low, and some have become a "garbage" tube, which is not the difference in quality of domestic electronic tube, but because the domestic electronic pipe is large. Some ports, Macao, Taiwan businessmen and foreign businessmen have acquired some domestic fever tubes in the Mainland. Now some tube prices have risen. The enthusiast can be used according to the tube of the hand, such as 6NL ~ 6N11, 6J1, 6J4P, 6J8P, etc., as long as the circuit is designed, the above tubes can be trial. That is, use ordinary components, as long as you carefully make and adjust, the sound quality will definitely let you look.
The above-than-top lines, as long as the assembly is correct, can be successful.
The equipment used by the author is not particularly, the sound source is a domestic HDCD machine for the production and careful calibration of PCML732, electronic pipes; the speaker is Yadick HBX5200. The purchase price of the sound source and speakers is more than 10,000 yuan. The speaker cable is a domestic Chinese-producing line of 5 yuan / m. The signal line is a domestic distribution line of more than ten yuan / m. The three daring front-level and the post-grade production cost is only about a thousand yuan. However, the three sets of equipment can match better, and its tone is warm and sounds, sweet and proper, and rational. The equipment author has used three years, there is no idea for upgrading the power amplifier, so the circuit program is recommended to the vast enthusiast. Set with a fashionable convince as the end of this article: "It's good to use it!"
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