El34 (6ca7) was the first five-percent audio power electronic tube launched by philips in 1956, when its appearance brought about an improvement in the sound quality of the audio amplifier, which was designed to have an anode-explosive power of 25 w (work data as schedule). Today, the tube, which is produced by the china sunset electronics plant, is sold both at home and abroad. El34's reborn sound is so beautiful that transistor amplifiers can't reach it. And that's why the transistor amplifier is so young and so strong today。
I. E-pipe characteristics
Electronic tubes are the first electronic amplifiers in human history. Speaking of the principles of electronic pipe work, it is an old and new topic for those who love it today. Owing to certain orientation biases and energy relations, the introduction and application of electronic tubes in my country ceased after the 1970s, which undoubtedly poses difficulties for the present timid fever. Here, some common sense of electronic tubes needs to be expressed。
An electronic tube is a vacuum that works using the power field, and when analysing its work, i can easily enter the house by using the n groove type of tubework that is now common. It's just that the cathode electronic launch of the tubes needs heat. The polar control characteristics and working principles of the two are very similar。
Compare current transistor amplifiers with their own characteristics: the temperature of the tube itself is stable and no giant radiator essential in the transistor is required: the second is that the load capacity is strong, and it's not as delicate as a transistor. It takes more than 10 minutes to burn a tube, so the device is safer at the time of the experiment, and the third is that the electrode amplifier is determined by its characteristics and needs to be connected to the load speaker through the transformer. In the event of a machine malfunction, the transistor does not harm the expensive loudspeaker system。
Be careful in the production and use of electronic tubes: inner pressure, be careful to touch electricity! The element shall have a high resistance reliability and welding shall be strictly prohibited. Furthermore, the electro-pipe hunger is strictly prohibited and speakers must be connected to the test machine。
An electronic tube is a vacuum electronic amplifier with considerable internal resistance working at high voltage. Its greatest advantage is to have a near-ideal magnification linearity. This advantage is that the transistors that have emerged are not yet achievable, making their use very simple, without the need for many active units to be used as a "co-synthesis" connection. This corresponds precisely to the doctrine of “simplified top”, which is one of the most important reasons why electronic technology was so highly developed in the 1990s that it was unique。
Two, electronic pipe output transformer
The output of the electronic tube is highly resistant and its equivalent is several orders of magnitude higher than the resistance of the electric loudspeaker that is now widely used, and the use of the output transformer to resist transformation is necessary in terms of resistance to matching: moreover, the power of the electrode amplifiers is in the form of high voltage, small currents, and the use of pressure-relief transformers is essential in terms of low-pressure high current energy required to drive low-pressure speakers。
For the rapid development of modern sound sources, the amplifier indicators are important, as required by the replicating of high security programming sources represented by cd singers. For electrode amplifiers, the magnitude of this indicator depends on the quality of the output transformer. The quality of the output transformer is very important. As this paper is an introduction to a british finished machine package, which is not specific to production, only addresses the issues to be addressed in transformer design and process。
The primary-to-number calibration ratio is derived from the output resistance of a particular electronic tube to the drive of a loudspeaker, so it is important to maximize the performance of the electronic tube by selecting an output transformer designed for a body。
2. In order for transformers to receive low-frequency response, the amount of electrons in the primary coil must be larger: from the high-frequency and phase properties, the transformers themselves must be as small as possible in parasitic, leakage, etc. Traditional transformers premised on radios and general-purpose amplifiers are clearly inadequate for modern requirements。
3. The transformers of electro-pipes to boost output, which, according to the power of the output stage, work in a state of direct flow together at both ends of the power supply, the signal is in a positive state and the negative half-week is mutually inversely dilated and amplified. In the direction of the circuits, it is important to prevent the saturation and loss of the steel core and reduce the volume of transformers from the direction of the magnetic field by running straight currents through two semi-rimonic clusters. At the same time, filtration-in-bad parasitic textures on the power supply can also be suppressed within transformers, which can help increase the noise ratio。
The rigorous and difficult process of e-output transformers is one of the main reasons for the high price of high-quality e-output transformers and electrode amplifiers。
Iii. Electronic transfer results
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Figure 1 simple output level
Figure 1 shows the structure of the common e-barrel-to-output line. The amplified two anodes of the electrode are attached to the two ends of the output transformer, with the working power ht being supplied to the electrode via the primary circuit through the flow of the head of the output transformer centre, and the load (speaker) being connected to the secondary end. The line follows a “fixed bias” route: the cathode of the electronic tube is directly connected to the ground (public points), the fence is connected to two resistances, and its public point is connected to the negative bias power source that meets the normal work of the two tubes, which is typical of the configuration of normal work of the electronic tube. The straight-flow work point of the electronic tube is also set as a “self-subsistence bias” approach, whereby the cathode of the electrode leads to a chain of resistance, using current currents in the electro-traffic circuit to generate a certain amount of voltage on the resistance, which leaves the cathode's level with a positive level difference relative to the “geo-” level, where the grid of the electronic tube can be connected to the ground level, reducing the additional circuits and increasing the component problems associated with the deployment of a grid-firing power. This so-called “subsistence bias” circuit applications are also high, but cathode resistance consumes part of the voltage and reduces output power。
The work of electronic tubes differs from model to model. And the same type of tube, with different anode working voltages, requires a different working bias of the fence, usually higher, which is more negative, and, conversely, the absolute value of the polar bias of the fence is reduced if it is not applied with the very high solar pressure given by the parameters. Typical working parameters for electronic tubes can be found in the relevant manuals. Moreover, the production of electronic tubes is much less discrete than that of transistors, and it can be said that the manual setting is generally not problematic。
The signal amplification route for the extended circuit of the pusher electronic tube is a front-stage segment, with the acquisition of two reverse symmetrical signal voltages into the grid of the two tubes, the management of the electron flow from the cathode, the acquisition of an amplified signal voltage, the integration of the transformer, and the output to the load speaker through a transformer coupling. The internal connection of the output transformer, with the same name end shown on the map, allows the straight-flowing wave (communicators) of the two anodes of power to be offset in reverse within the transformer, while the reverse signal composition is converted into the same increase within the transformer. Power is generally increased by about twice as much as a single electronic tube. (the output efficiency of the specific working states of a, a, a, b, and b is not compared here, and this is the working state of a and b. The hyperlinear state of triodes, beams, pentapolars and populars is not explored here due to its many facets, and the machine is typical of the p5 mode of operation。
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Figure 2 mixed power discharge full circuit (one channel)
Figure 2 shows the map of mixed power discharge. Once the specific elements of the ecm have been explored and described separately above, the whole machine is analysed and it is believed that you will understand better。
The graph shows the lines of one channel for this stereo amplifier and the same circuit for the other. Analysis of this amplifier can be found in three parts:
Power, which includes high voltage ht from electro-pipe magnification of anode power supply, 6. 3v voltage from heat-heated electro-channel el34 “thermal” (commonly known as lumber), and a transistor q1 and q2 work together with current-60v current voltage from transformer t/t。
2. A pullover power magnification consisting of an electronic tube v1, v2 and surrounding elements and an output transformer。
A differential voltage magnification level consisting of transistor q1 and q2. This level has three main functions:
A. Composed of differential voltage amplification, which amplifies the weak signal voltage entered from the output end to the voltage of el34 sufficient to drive the power magnification tube: b. The separation of the signal voltage by a simple differential amplifier to produce the balanced voltage output required for the driver push amplifiers. C. The entire circuit is based on improved performance. The static straight current bias of the tubes v1 and v2 (this is a 30-volt machine) is based on a direct flow coupling method that is not compatible with the electric caps, which is also obtained by the aggregate electrode level of the transistor q1 and q2 and does not set a static adjustment element for the electronic tubes, as is the case with the general rc table。
One of the great advantages of this design is that it cannot be achieved in a general design, i. E., that most of the two stages are symmetrically balanced, with a high cosmetic inhibition ratio, so that the texture and power interference signals from the source end can automatically be offset and suppressed within the amplifier. Therefore, the amplifiers that this design contains, such as noise, noise, etc., are very low, and the noise is more than sufficient for the digital acoustic requirements for amplifiers。
Enter the signal from the base pole of the transistor q1 to the power input level. Q1 and q2 form a differential voltage magnification level. R3 is a public radio polar resistance to this differential amplifier
