6p9p and push the powerful bile power circuit
Author: Wen Kang
The circuit and component values after the whole machine are applied, and the working voltage values of each point are shown. There may be problems that may exist during debugging, indicating as follows.
6p9p is a classic push power amplifier tube. Standard state operating parameters are: UF6.3VIF0.65A, UA300V IA 30mA, UGL-3V, S 12mA / V, related parameters: CSR 13PF, CSC9.5PF. UA MAX330V, PAMAX 9W, UFK MAX ± 100V, RG1 Max 500kΩ. The 6P9P internal resistance is high, and when the transformer is pushed, the primary P-P AC impedance of the output transformer is 10 kΩ. Taking this circuit mounted as an example, the end load can obtain 10W failure when the input is fed into a 1V audio voltage.
Inverted level is negative gain, generally considering balance, adjustment gains at 0.7. In the 6P9P parallel state, the absolute value of the input negative pressure is approximately 8V, so the 6N2 does the voltage amplifies, and the push part is placed between 50 and 70 times. At this time, nonlinear distortion is not more than 3%.
6H2 (6ALs) in the circuit can be used without, there is a small current high-inductive E-type choke instead of obtaining different sound bottoms, isolating crosstalk noise.
Under the split structure, the power supply selects the connection of "front stone bile", the bridge rectification of the transistor portion is greatly reduced, and the high pressure winding process of the transformer is greatly reduced. After the transistor is rectified, it has been specially rectified bile duct as secondary filtering, which not only has delayed anti-impact, but can make a soft and just good performance from sound effects.
100Ω resistors in the rectifier circuit are anti-impact resistance, and 10Ω resistors are average current resistance.
It is important to emphasize that the gate leakage resistance of 6p9p is required to enter 1.5kΩ anti-vibration resistance per arm, otherwise it will not work. After the tube, each channel S will increase to 24 mA / vx2. In addition to the above steps must be guaranteed, the welding time-related components and wiring should be close to the baffles, the shortest line is shorter, and the components in the entire circuit can be reduced, and the potential impact of the self-excitement.
The inverted portion may cause the high-frequency signal due to the parasitic capacitance of the discrete difference between the tube to cause the high frequency signal to be asymmetrical at the positive and negative half weeks, resulting in distortion, bringing a hard roughness on the hearing. The solution is to 6N2 6. The high quality small capacitance is high-quality to the ground to achieve high frequency deterioration.
When the circuit is pressed UA 300V, IA fluctuates up and down in 40 mA, and the working status is nearly. Under loading conditions, input IV continuous sine waves with signal generator, in the -3dB range, from 35 Hz to 50 kHz, and very flat. Output transformers are taken from Sichuan "Kay Li" brand finished product, P-P10KΩ, and power margin is only 15W. There is no way to work with the large loop negative feedback during debugging, and it is not shown in the figure. Description design is reasonable.
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