STK4040x1 made HI-FI amplifier circuit
Posted on Nov 10, 2015 6750
A preferred STK4040xl Fi amplifier circuit that has good pull electrical parameters: in sv, RL Uc = 43 - 8fl conditions,
the rated output power of not less than 70W, the maximum harmonic distortion of only 0.008%, typically 0.003%, 3dB frequency response of 20Hz ~ 20kHz. Such outstanding performance, the amplifier circuit is indeed rare. As shown in Figure 3-46 for its internal equivalent circuit port VT3, the constant current source circuit R 1, VDl.VD2 composition as a differential pair VTl, VTZ common-emitter impedance of the input stage to improve magnification and common-mode rejection ratio . Differential stage single-ended output signal through VT8 base, as an incentive level input o VT7, VT8 together form an approximate cascode circuit, at the same time, VT7 approximate common base connection, itself a large voltage gain, and VT8 incorporated in and constitute a voltage gain of the driver stage is still high. More importantly, because of the grounded base VT7 with isolation and shielding effect, the output signal VT8 not easily back to the input, to ensure that the driver stage T for more stable. Into further reduce distortion o VT6 and R2, VD1, VD2 composition of the other current source circuit as a driver stage of AC load, it is more than the S & P resistance Load (eg STK46: 5'STK4151 and many other integrated amplifier), a higher exchange impedance, gain more, work is very stable and reliable 6 VT9. R8R9 and VD3 composition of a "constant voltage multiplier circuit," constant value R8 and R9 mainly by the ratio of the decision. Compared with the official regulator diode series circuit better, dynamic resistance is smaller, the more the output stage of the DC bias stability, more symmetrical waveform excitation signal, less distortion. VT10.VT11 and VT12.VT13 composition full symmetry PN P NPN Darlington on the tube, so that the output stage circuit more concise, symmetry, good linearity, low distortion.