"Keywords: 326P, 6P9P tube circuit
Use 6p9p to make an ear
System terminals in the audio family are electrical energy-acoustic energy conversion, speakers and headphones play a role. Compared with the speakers, the headphones have a lot of limitations, such as basss, but only in the eardrum, there is no shock, no speaker. In addition, there is a sound field that seems to be in the foregoing and the brain, and it is easy to fatigue. However, the headphones also have its innate advantages, and the headphones are basically a lightweight earthquake film covers full frequencies, and there is no multi-speaker consisting of multi-units. The frequency response curve is relatively straight, and there is excellent transient that can easily capture the details in the music. There is also a relatively low price, the speaker should be equivalent to the sound and transient, and the price does not know how many times the rollover. In addition, although only single exclusive, you can listen to music under large volume without affecting others. So I can't afford the speaker of the sky, and I have a demanding sound quality, or the home environment is limited to a good listening environment, the headset is really a shortcut. In addition, to exercise your own identification ability to sound, form your own listening standard, have a high-quality headset, which is undoubtedly helpful.
one. The primary literal author likes to listen to headphones, especially high quality monitor headphones. In many brands, there is a special feeling of listening earphones in Senhael. As early as 1945, Sennheiser, Germany, successfully designed excellent microphones and headphones, and is well received by the industry. Regardless of sound quality, quality, comfort, and crafts, Senhe Selsere has unique, the Offis headset system of the Ofs, which is almost the reference standard for the world's best earphone. The author is a newspaper magazine through audio and magazine in the early 1990s, and learned about the "Alliance" HD580 of the moving circle headphones. After listening to HD580 in the home of a bliss friend, I deeply shocked the small square. The bulky scene. The smooth treble, the ethereal is like a fairyland; the low-frequency domineering is unable to imagine how this "waves" is poured from this small headset. The most unforgettable thing is the truth of the sound, as if listening to the singer of the singer, the player's play. For what high-grade equipment did not really touched at the time, at home, at home, this sound is like a fairy, it is not from the world. Since then, the author has a preliminary understanding of the real "sound". At that time, the price of HD580 was close to 3000. For a few years of graduation, it was a "huge sum", but it was because of the listening experience, with "struggle" goals. Later, I also knew that this HD580 has a more great HD600, since then has a heart knot: When is it crossing HD580, I have HD600 directly. More than 10 years of change is huge, there is not a few people who can imagine that this life can have a private sedan, and now this year, the incredible thing is not imagined in the past, more and more families have or will become a reality. Thanks to the country's growing strength, let's make another dream be a reality. When you have a time, suddenly I find a pair of HD600 is no longer a dream. The author has purchased a Senheye HD600 more than 3 years. If you have, you will have a good equipment, and you haven't used the excitement of HD580 when you use HD600.
two. 6p9p Motion 6P9P is a side-by-heat oxide cathode output five-pole, the use of the manual is to amplify by broadband power, indicating that this tube is used in high frequency field, but can actually come into contact with Take 6P9P in all types of tube machines. In recent years, some people use this tube in the audio amplifier, but still have little. The author did not actually use this experience, this tried to use it in the ear of the HD600, but the effect is satisfactory. The program is very simple, as shown in Figure 1. A total of two levels were magnified. The front is the SRPP circuit voltage amplification, and the rear level is a single-ended circuit. The first stage is connected to the SRPP line to do voltage amplification with a 6n3. The SRPP circuit has a small distortion, strong control, and high and low-ends have a good extension. More than 10 years ago, there was a panic in China, but because the sound is too sound, the sound tends to be bright, and the medium and low frequency is thin and lighter. In recent years, it has been treated with cold, almost a symbol of no taste. Anything in the world has two sides. In this year, the audio predecessors put the SRPP circuit from radio frequency to audio, which is to see its excellent medium and high frequency characteristics, where low frequencies are a little bit thin, but there is a good control, so he is listening There is a refreshing autumn, and the HD600 is rich and thick, just can be resolved in this refreshment. It can be said that the SRPP circuit is used herein is a balanced tone here for HD600. Both 6N3 and 6N11 are used in high-frequency medium μ tubes, which are very suitable for SRPP lines. Compared to 6N3 internal resistance, cross-guided values are small than 6N11, but there are fewer gallbladder in 6N11 sound. The SRPP circuit is more showed the taste of the transistor, and the 6N3 charm is better compared to the 6N3 charm, and the price is more advantageous, so the motor voltage amplifies 6N3. This level of current is not very large, about 3.4mA, is adjusted according to the characteristics of the HD600 and the author's listening habits. 6N3 cathode 430Ω resistor has no parallel capacitance, introducing a small current negative feedback, although a little gain is sacrificed, but in exchange for more stable working conditions. The voltage amplification of this level is about 17.5, and about 25 dB. The second level uses a wide frequency five-pole power tube 6p9p to be used as a triode state, and there is no special purpose using 6p9p. It is a ready-made tube, and I want to do an attempt, and this tube characteristics are also good, it should be satisfied This ear is required. Since this 6P9P is very small, relatively cold doors, the price is very low. The basic parameters of 6p9p are as follows: the filament voltage is 6.3V, the filament current is 0.65A, the limit screen pressure 330V, the limit second gate voltage 330V, the limit screen is extremely power consumption 9W, and the cross guide 11.7 mA / v. Since 6P9P in this circuit is a state in which the triode is connected, 6P9P does not have a ready-made parameter in the triode state, and we can calculate according to the I / U curve in the triode state, and can be refer to FIG. 2.
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First calculate the cross-guiding value first. The concept of cross-guiding is: under the condition of fixed screen, the gate pressure changes the change of LV and the output of the screen. Take the screen pressure 160V in the figure, it is assumed that the gate pressure changes from -6 to 0V, and the screen stream varies from 20 mA to 110 mA, so that from the formula S = ΔO / △ u. We can calculate, s = (110-20) / [0 - (- 6)] = 15 mA / v. Then, see the internal resistance of the triode state 6p9p. The concept of internal resistance is the amount of screen pressure variation caused by the change in the unit screen change under the condition of the gate pressure. Still referring to FIG. 2, it is assumed that the gate pressure is fixed in -3V, the screen changes from 90mA to 40 mA, and the screen is changed from 240V to 160V. According to the formula Ri = ΔU / △ I, internal resistance Ri = (240-120) / (0.09-0.02) = 1714.3 Ω can be calculated. With the value of cross-guided and internal resistance, it is easy to obtain an enlarged coefficient μ = 15 × 1.714 = 25.7 according to the formula μ = S × R. The 6P9P in this unit power amplification is in the form of self-bias. It is the bias form of the author when making a single-ended amplifier. Compared to fixed bias, the self-bias sound is more alcohol and more charming. The relative power tube is safer, unlike a fixed bias, once the problem is negative, the whole power tube is hot, and a new tube can be burned in a few minutes. However, the power amplification of the electron tube operating in the self-bias state is less than the fixed bias in the same case. In other words, the advantage is achieved by sacrifice efficiency, good power required by the earphone, for headphones, this ear is already a large power reserve, does not care about that loss. 6p9p cathode resistance value 400Ω, the static operating current is 19.5mA, the maximum screen Ia = 39mA, estimated from the I / U curve of Fig. 2, at this time, the saturation pressure drop is about 95V at this time. It can probably calculate the power amplification stage at the end of this machine, the optimum load impedance = (214-95) / 0.0195=6102.6Ω, the output transformer is 6.5kΩ, this state and the output power of about 1.1W under this load, so The power is huge for HD600, and the thrust is completely incomprehensible.
three. The selection of components and the circuit's debugging machine circuit is simple, the parts are not much, but the quality and quality of the spare parts are closely related to the sound quality, and it is not possible. The resistors used in the main radio circuit are mainly carbonaceous resistors like the author, including R1, R2, R3, R4, R6, R7, and power supply: R8, R9, R10, and power tubes, cathode resistance options for use with big red cannons, take High reliability. The choice of capacitors is also very particular. The only coupling capacitor C1 is selected for WEST-CAP axial oil immersion capacitance, and the sound performance is compared, analyzed and charming. Power Tube 6p9p cathode capacitor uses the electrolytic capacitance of the MBI card, which is a rare sign, something that is from the old goods market. Received several kinds of brand-name capacitors. Power filter Capacitor C3 uses Japanese Nichicon, C4, C5 with Philips's Dongxiang. The tube 6N3 selects the T-grade of Beijing 1980, 6P9P uses Nanjing 1960 6π9c, the early domestic 6P9P. 5Z2P uses Liuzhou products in 1975. All pipes are ready-made things, and market students are also extremely low-cost cold door tubes. Power transformers and output transformers are the author's own design, which is customized in a well-known audio transformer manufacturer in China. The power transformer power is 150W, and the output transformer is by 25.4 mm, the stack of 30mm core is wound, and the structure is shown in Fig. 3, the static parameters are as follows: one side inductance 16.7h, the leakage is 15.2Mh. It is not difficult to calculate, the high frequency is limited to 70kH z, the low frequency lower limit is 62 Hz. Although the low frequency lower limit is relatively high, it is under the conditions of full power, and the power of this ear is pushing HD600 for the power of the HD600, which is not used at all, and low frequency in such a small power state. There is no problem that there is no dive.
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Electronics in the power circuit use the old products of Shanghai Radio Qi Qi Factory. It turns out that this inductance still wants to omit, but the result of omission is that the exchange is increased, even if the resistance of hundreds of European can not be eliminated, the single-ended circuit cannot cancel the communication, plus the hear of the headphones, and propose the power supply High requirements. Debugging is also very simple, after the circuit welding is completed, first inserted by 6N3 and 6P9P, open the power supply, observe whether the filament is normal, the filament is normal, and then inserted with 522P, then measure the voltage in several key points in the circuit: main filtering The capacitor is about 241V of the inductive rear end voltage; adding the voltage of 1.6V; 6P9P cathode resistance on the voltage of the voltage 208V; 6N3; 6P9P cathode resistance is about 7.8 V. Due to the discrete properties of the power tube, try to use a cathode voltage approach.
Four. The listening evaluation has been put into use for two consecutive weeks, this ear can be put into use, and the appearance is shown in Figure 4. The audio-listed equipment is as follows: The source is the early laser player CDP-701ES with SONY. The signal line is soldered by Turkon oil, and the ear is a native, the headphones are the author's HD600. Since this earphone has a period of time, it will enter the state, and it can be obsessed with the performance of this ear. CDP-701ES is an early product. The price is expected to reach 260,000 yen. Although it has experienced more than 20 years, it has now entered the annual year, but it is still worthy of the top products of the year, the process is excellent, the sound is gorgeous, and the performance does not lose Today, the product is one of the favorite products, and the sound performance is also good with HD600.
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The effect of the HD600 is self-evident, but it is not suitable for any ear, the same is not good or the quality is not good enough. Its effect is dull, which gives people a feeling of "people with virtual name". But this HD600 has great potential, and it is to be excavated by the player, but also the different CD and signal lines, and the ear is more important. It is the first time with 6p9p, it is the first time. But when the ear is pushed on the HD600, when the music sounded, the author felt gratified, and it was not a bad luck. First of all, the sense of signal is first, we all know that single-ended lines are more difficult to handle the handling of exchanges, and single-ended ear is more demanding because of the high sensitivity of headphones. The residual exchange of this unit is very weak, and it doesn't feel unrecognizable. Second, the author is more concerned about the low-frequency problem, this ear is better. Low frequencies are both HD600 strength, and it is also difficult to deal with the shortcomings, which is very rich, unusually thick and unbearable, and it is difficult to handle it. The design and manufacturing process of this ear is targeted, and the real-listening effect also confirmed the purpose. I feel deep when I am in the 9th track Promenade of Doljian Sample Vol II. This is the music playing in the church, the momentum is magnificent, and it is very profound. But it is necessary to truly express the low-frequency quality of the duct, in the entire audio system, there is no matter what the problem in the low frequency band, it will be chaos when this music is interpreted. Here, 6P 9P's single-ended-ended HD600 performance makes me feel very satisfied, the huge momentum can be easily expressed, rare is very true of the low frequency quality of the organ. In high-frequency sections, the HD600 analytics is not suspicious. When the equipment is sufficiently high, the HD600 has a transparent near the electrostatic headset. The high frequency of this ear is in the charm, and the uniqueness of the single-ended power amplifier is well reflected here. The interpretation of the "famous monkey" was verified. This record of the 250th anniversary of the past 250th anniversary of the great violi craftsman, the track is played with Stradorian, here the ear is in line with HD600, high-frequency flungery crystal clear, no shortage, put the strad name The noble tone of the piano is full of performance. The intermediate frequency is almost impossible for HD600. In this combination, regardless of the density of voices or the texture of musical instruments, it can perform well. From Cui Yanguang's female voice, it can be reflected in more detail here.
Fives. Soon, the HD600 upgrade alternative product HD650 has appeared in all aspects, and it is said to have more than HD600. The author is enduring, endingInsufficient research, I bought HD650. From the perspective, these two way brothers are almost a model, which is extremely similar, but the connection HD650 is thick and strong. The plug is also delicate. In order to have an objective comparison result, I bought it in the early years, I now bought the radius of the radio, transferred to a radio, and insert the HD650 into its headphone interface. Open the volume to a suitable location, keep the HD650 work for more than a month, and the same brother HD600 is more energetic. HD600 analysts are super group, the sound is biased, but the female voice teeth are a bit, the HD650 is just right; when listening to the male voice, the HD650's thick feelings are better than HD600, but the HD650 is slightly insecure when listening to jazz. The medium frequency alcohol and dense are equivalent, and the low frequency is the most obvious improvement in HD650, the texture and control are more advanced, and the sense of urgency is better. And the depth is still HD600, the HD600 has a low-frequency low-frequency makes it impacted, highlighting the next dish, and plays a discount in terms of control, that is, with thickness, depth, but sacrifices a little. In general, the HD600 to HD650 is a progress. It is undoubtedly better adaptability to the high frequency of all kinds of software, but unfortunately, HD650 does not make complete transcendence. "
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