Keywords: use 6n2 production 靓声 声 前 级
Homemade an electronic tube power amplifier, first select a power output tube, then select the circuit, and then custom power transformer and output transformer according to the electronic tube used in the electronic tube and the desired circuit. 6P14 (foreign model EL84) This pipe is in the most prosperous period of the electronic management, which is known for the audio amplifier circuit, and it is not as famous as some common power amplifiers such as EL34, KT-88 and 6L6, because Its single-ended output is only 3W, while the push-pull output is only 17W. Compared with the push-pull output of the EL34 triode approach, how many people will see this "little brother"? But you can't take this electric booth, it is developed for the audio circuit. It is quite good when using it correctly. This article introduces a practical circuit. Be
The whole machine circuit can be divided into 4 parts: amplifying circuit (Figure 1), filament and negative pressure circuit, high voltage circuit and measurement circuit (Figure 2). Be
This machine's electricity amplifier is selected for 12T7, 1/2 12AT7 as a voltage amplification and straight coupling to the inverting circuit. The inverting circuit is made of 1/2 12AT7 shot - covered, not the current use now The long-tail inverting circuit is because the gate bias of the 6P14 is low, the push of the pP ask for approximately 20V, with 1/2 12AT7 to make the screen, inserted. Power amplification grade - Push-pull output for 6P14, the power is really poor, I am afraid I can't drive my LS3 / 5A, so I have selected 4 6p14 for each channel, parallel. Compared with the push-pull, the adverse consequences will feel that the string is "thick", in order to make this machine availability, it makes it up, it is possible to use 4 parallel. It can also be used in two push. Compared with the "simple" of the amplification circuit, the power part can be "complex", the power part is used as the integral circuit energy supply, and if not - set a good power system, better amplifying circuit design, it is impossible to make it Designed to the highest realm, based on this - point, the unit is designed to be "complex". It is generally considered that the high pressure is rectified, and it is already "fever" by the CLC π type filter, which is already "fever", and the experiment is π type. The DC voltage obtained by the filter will still be dynamically changed with the fluctuation of the market and the power amplification power output, so that the operating point of the amplified circuit is deviated from the original design. The unit is used by electronics to solve this - The problem, making the output voltage from being affected by the external and internal effects, after the anode voltage is constant, only the remaining gate negative pressure in the operating point of the power amplification circuit can affect the operating point of the power amplifier circuit. In the constant state of the anode voltage, if the gate negative pressure is not regulated, the anode current of 6P14 will change as the mains fluctuations (except for the self-bias). The amount of change is small, but for circuits that have been constant, the gate negative pressure is not desirable, so that only about 10V is about 10V at the gate bias of 6P14, and the three end regulators are used. It can easily get it easily. Be
The practice of power supply with the voltage amplifier tube filament is often used in the pre-stage amplifying circuit to improve the signal-to-noise ratio of the whole machine, and the method of separating the filament transformer and the high voltage transformer is also one of the methods of improving the whole machine signal-to-noise ratio. . The unit takes a 60mA current table and 4 normally closed reset switches at the 6P14 cathode, which can easily monitor the cathode current of 6P14, which makes it easy to replace the 6P14 upset debugging process. Be
In the selection of components, it is recommended that the power transformer uses the R-type transformer, the performance of the R-type transformer is better than the C-type transformer, and there is no common humming that the C-type transformer, and the traditional EI type transformer sound is too thick. The blocking circle can be used in the selection, E1 type, C-type, XED type in terms of sound, there is not much difference. Electrolytic capacitors can be used in the United States to produce sprague, mallory. 4 coupling capacitors, it is recommended to use German WiMA, resistance can be used in China's professional manufacturers, and if conditions allow for selecting some "tonic" levels such as Dale, A & B. This machine 12at7 is the Japanese Ten production, TEN's tube not only has a luxuriant of the US tube, but also has a sweetness of the British tube, and there is no other Nissan pipe. The 6P14 can be used in Beijing, and Beijing Electronic Pipeline production 6P14 has already About 40 years of history, quality and voice are quite excellent, of course, the price of imported tubes is more "excellent" factory, but the sound is abroad - some famous brands, such as Mudland's EL84, still a little bit, 6080 I use domestic 6N5P, 6N13P, 6N22P. 6SJ7 selection is relatively large - some can be. This machine is also very simple, such as welding, simply adjusting the high pressure to 320V, plugging the tube to adjust the RPL-RP4 and press the measurement switch to make the header pointer at 37mA. Connecting the speaker if there is no communication sound and abnormal, you can answer the audio source. All the work needs to spend a little savings and four or five days, you can listen to the electronic pipe power amplifier you make! This kind of fun can not be expressed in words.
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