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H6Bservice manual download site
H6Bservice manual download site
3.C class a amplifierH6Bservice manual download site
Class c amplifier input of the transistor characteristic curve is shown in Figure 5, the quiescent point for the Q-point, located under the cutoff, only over bias point part of the input signal, power transistor conducting. While this approach is more efficient, but due to the excessive distortion, used in audio amplifiers, generally used for high frequency power amplifier circuit, used as a multiplier, because in the amplifier's power tubes of collector harmonic-rich, with a high Q tuned circuit in the second harmonic, full waveform frequency sine wave output.H6Bservice manual download site
Second, conventional audio amplifier circuitH6Bservice manual download site
Normal audio amplifier circuit has a lot kinds, are most frequently used in the amplifier DC introduced complementary symmetry power amplifier circuit as an example.H6Bservice manual download site
Distortion of the amplifier circuit is simple, with the advantages of low noise, high slew rate. As shown in Figure 6. The power amplifier distortion power of 100W to 5 ω load, input sensitivity 300mV output noise voltage is 1.2mV.H6Bservice manual download site
H6Bservice manual download site
In the circuits, diodes D1, D2, isolated power supply to increase in large dynamic range burst-mode signal input preamp circuit driving ability. When large dynamic range burst-mode signal comes, the final output tube currents increase, forcing the power supply voltage falls, then reverse segregation as D1, D2, the voltage on the capacitor C5, C7, mutation, can still remain the primary voltage, so the promoted grade is still able to provide high voltage and large current and make the voices sound more powerful. Due to the large dynamic range burst-mode signal often appeared in low frequency band, thus the use of this technology in particular is of great significance for the ultra low frequency power amplifier, confirmed the sense of actually listening to it.H6Bservice manual download site
The DC operating point of the circuit is determined by the design and input differential of tube current of which is 0.9mA, the static current of 80mA output tubes, work from the AB class. For improve output level static work points of hot stability, in its partial reset circuit in the used diode D3-D5 and negative temperature coefficient thermistor R10 for temperature compensation, which R10 posted loaded Yu amplifier tube thermal device Shang, move on improve amplifier of hot stability is effective, late level tube of cold, and hot state static current can control in 30mA-80mA within, without "warm-up", a boot will can entered more better of work State. If not using R10, 0~100mA the range of cold and hot state of quiescent current. If the value of R10 to 200 ω, thermal stability, it could rise further.
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