Low Cost Integrated Circuit Power Amplifier 03

This amplifier is suitable for entry-level audiophiles who are working-class people to make their own 6. It has the following features:
(1) Using a power supply filter, as shown in Figure 5-52, the music background is very clean and the signal-to-noise ratio is improved.
    Figure s, 52
    (2) The power supply filter capacitor uses 10 2ZOOt-JtF ordinary electrolytic capacitors, so that their equivalent series inductance and internal resistance
are lower than the 1000OrjeF audio-specific electrolytic capacitors.
    (3) Use CMOS integrated circuit CD4069 as preamplifier, as shown in Figure 5-53. I once used NE5532 as a preamplifier
because the closed-loop gain was only 2 times and high-frequency self-excitation occurred and failed, so I changed it to CD4069 and succeeded in one fell swoop.
    (4) The left channel of this machine uses inverting amplification to enable the two LM3886s to draw current from the positive and negative power supplies evenly, and the power supply voltage
is always symmetrical, thereby improving the sound quality, making the bass deep and powerful, and the midrange bright, as shown in Figure 5·5 4 Shown in white
    <5) adopts a flexible peak clipping circuit, which makes the rear stage less likely to be overloaded and
the speakers less likely to burn out, and adds pleasant even-order harmonic transitions.
    (6) The feedback method of this machine's LM3886 is a passive servo type, which reduces
the impact of large-capacity negative feedback DC blocking capacitors on sound quality.
    (7) This unit uses two volume potentiometers, which can change
the degree of peak clipping to change the tone. You can also enjoy
"bold" music at a low volume.