Make your own home theater AV combo with superior performance 03

The AV combination is shown in Figure lo-2. The first stage uses Philips
TDA1029 as a four-way input switching signal switch; the second stage uses
NE5532 as a preamplifier and B-NEC's pPC18 92
four-way surround sound processing circuit. Main signal and surround, center signal output,
and control of high and low tone, volume, left and right channel balance, surround effect control
and three sound field effect simulation options; the third stage uses MS381 to
achieve three-dimensional optimization of the front pair of speakers Sound field effect processing; the suffix
is ​​TDA1514A and TDA15 21 (or LM1875) for power output
. TDA1029 is a stereo four-way high -fidelity audio signal switching integrated circuit
    used in the audio field . Working voltage: 6~23V, typical value is 12V, total harmonic distortion is only 0.005%, excellent signal-to-noise ratio (V=120dB), conversion rate 5-15V/Ftso typical application circuit is shown in Figure 10-3 Show.     ruPC1892 is a four-channel surround sound processing circuit with excellent performance launched in 1995. The circuit adopts a matrix phase-shifting surround sound processing system, which can separate the two-channel signal and the mono-channel signal into two main channel signals and One surround channel signal and one center channel signal (during actual production, it was found that one of the two sub-channel signals of PC1892 is the center signal) o This circuit is equipped with concert halls, cinemas and analog stereo and stereo Pass-through sound field effect mode. The circuit is equipped with surround sound effect control, main amplifier balance, treble, bass and volume control inside the circuit. Some of the controls adopt DC level control, which reduces the noise of the circuit to a very minimum. Anal P ('1892 is equipped with amplifier , low-pass filter, mode control 1 phase shift, effect processing, compensation absorption, tone, volume, balance and other circuits inside. pcPC1892 is a large-scale integrated circuit. The application circuit is as shown in the figure . As shown in 10-4, the typical operating voltage is +12V, and the control part uses +5V. The audio mode control is controlled by the high and low level programming . The functions of each potentiometer are as follows: RP1 is the back surround channel Sound effect volume control, RPZ is the front left and right channel ear balance control, RP3 is the left and right channel volume control, RP4 is the front center channel volume control, RP5 and RP6 are the low and treble tone controls of the front left and right channels .The function of turning si and S2 is: sl high level and sz low level are concert hall mode; sl low level and S2 high level are cinema mode; sl and SZ both high level are analog stereo mode; Sl . S2 is both low level and is a stereo pass-through state port.