Keywords: 6C19 parallel single-end power amplifier
6C19 is a cheap pipe, many people don't cut it. The author saw it on the stall, I liked it very much, and the thick grid, wide thick screen, although the small nine single-triode, but there were 11W anode dissipation power. The manual learned that the tube is mainly used in a voltage adjustment tube in an electronic regulator, which is characterized by low-screen pressure, low internal resistance, large current, and the above parameter indicated that 6C19 is actually a cool tube. The famous 300b was developed at the time, and it was used as a voltage adjustment tube. Later, it was used by audio enthusiasts, which was used for audio power to enlargement.
In the process of years of fever, the author always maintains a strong curiosity and hands-on desire. It is to see the advantages of 6C19 internal resistance. The requirements for output transformers are relatively low, and due to low internal resistance, high damping coefficients, Hand has strong control. Single-ended-based power amplifiers made with 6C19, about 2W left and right output power appear to be small, and the method of using parallel can be used to increase the output power. The author uses 2 parallel, the output power is up to 4W, has been different from 2A3, if this is very cheap, it can be used moderately, which output 5 ~ 6W is no problem.
Since the gate negative pressure of 6C19 is high, the push voltage is high, the author is inspired when considering the circuit, and the article from a magazine is inspired. This paper introduces the 6K4 push of 6K4 in the early tube radio, and the effect is surprising. In the hair burning circle, there was a statement that the five-pole push triodes capable of compensation, so the author uses the cross-guided high, the power consumption, the four-pole 6J9 of the anode current is 6C19, and the circuit is shown in Figure 1.6J9 abroad. Model 5842 is a classic pipe for pushing 300B. The basic parameters of 6J9 and 6C19 are shown in the table, and the pins are arranged in Figure 2.
Several key issues in production
1. Power transformers Although 6C19 is an inexpensive tube, the selection and production process of components cannot be horses. The power supply transformer has a capacity of more than 180W. The current capacity of the high pressure 160V winding is greater than 300mA. The filament windings are divided into 3 groups, and the first group 6.3V is 4A 6C19J, the current capacity is greater than 4A, the second group 6.3V for 2 6J9J, current capacity is greater than 0.7a, the third group 5V is 5Z4Pa, and the current capacity is greater than 5A.
2. The output cattle is applied with a 32mm × 50 mm imported iron core, and the film thickness is 0.35 mm. Three-fold diced wound. The primary use of φ0.33mm enamel wrap around 1260, 420 per layer, the secondary φ0.9mm enamel wiring around 98, 49 per layer. Negative feedback windings with φ0. 14mm enamel wire by 100. Silicon steel sheets are sluggments, and the air gap is 0.3mm.
3. The rectifier circuit is larger than the current 4 6C19, and two 5Z4PA is used in parallel, R11, R12 is a current resistance. The filter circuit uses electrolytic capacitance, oil immersion capacitance, and CBB film capacitors, which is conducive to improving the response speed. Two chokes composed of ClClc two-stage π-type filters, making the supply of 6J9 voltage amplifying the current more pure and smooth.
4. Coupled capacitors use CZ30-2 axial lead oil immersion capacitors produced in early Shenyang Dongguang Plant, and then two in parallel, one RIFA0.02μF / 400V capacitor is connected in parallel, and the high-tone penetration is amazing!
5. debugging
1) Before powering, the output transformer secondary is connected to the 8Ω5W resistance as a false load. After powering, the voltage should be basically substantially compliant, and the next step is adjusted. 2) Adjustment of the power part. When the entire circuit belt load is basically normal, the B + voltage should be measured at around 165V, such as deviations, the R13 20Ω5W resistance can be adjusted. 3) Adjustment of 6C19 Cathode Resistance R10. According to 40V (cathode voltage) ÷ 220Ω (cathode resistance) = 0.18a, 0.18a ÷ 2 × (160V-40V) = 10.9W, no more than 6C19 screen consumption 1 1W. If the voltage is deviated, the R10 can be adjusted, in short, it is necessary to meet the above conditions. R8, R9 is an anti-vibration resistor. 4) Adjustment of negative feedback resistor R14. First break the R14, complete the machine adjustment, and then connect to the sound source, then connect to R14, if the sound is small, the negative feedback is correct. If the sound becomes large or a whistle, the negative feedback is reversed, and the negative feedback coil is switched. The R14 is then replaced with a 200 kΩ potentiometer, and the music side adjustment potentiometer is listened, and it is considered that the distortion is the same as the resistance of the same resistance.
Adjustment to a paragraph to be put into use, two weeks to one month will be reconfigured once.
The signal to noise of this unit is relatively high, and noise is heard near the speaker. It is featured that the bass is deep, and the shock has to exceed 300B. Compared with 2A3, its charm individual believes to listen to some.
Schedule
Be
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101019j 10J9J
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电压 (V) 10 10 10
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电 电 电 (A) 1.00 104
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Anode voltage (V) 1010 10
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Anode current (MA) 105 10
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Gate voltage (V) 7 - 7
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Out (1 "nan) portfill 10 10
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中阻 (q) 300
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Maximum anode dissipation work (W) 10 3 3
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