Multi-sound sound system design using UPC1892

The entire circuit is divided into two parts: the first part uses the four-channel surround sound processing chip μPCI892 produced by Japan's NEC Company (see picture). It is equipped with amplifier, low-pass filter, mode control, phase shift, effect processing, compensation absorption, Tone, volume and balance circuits. Pins (25) and (26) of the chip are the input terminals of the left and right channel signals respectively. After amplification and processing by the internal circuit, they are divided into four signals, which are output by pins (9), (12) to (14) respectively. The four-way power amplifier in the second part (see Figure 2) can produce a wonderful four-dimensional surround sound effect.

The chip also presets three sound field effects: concert hall, cinema and simulated stereo. The sound field effect switching is controlled by the level of pins (7) and (8) of the chip, as shown in the table below. You can select through S1 and S2 during use. Potentiometer RPl is for music effect control, RP2 is for output level control, RP3 is for front left and right channel volume control, RP4 is for rear surround sound volume control, RP5 is for bass control, and RP6 is for treble control.