Homemade multimedia active speakers

Circuit principle:

The circuit is shown in Figure 9-68. TDA1524A is mainly used for DC volume and tone balance control in HI-FI audio systems. It avoids the noise generated by directly using a potentiometer to adjust the volume and tone, and only one potentiometer is used here to complete the volume, tone and balance control of dual channels. In addition, TDA1524A also has the ability to handle input signal overload, avoiding overload distortion. For low-level input signals, the volume control knob of TDA1524A can also provide a maximum gain of 21.5DB.

LM1877 is an operational amplifier type dual-channel audio power amplifier, which is particularly suitable for use with TDA1524A circuit. LM1877 has a complete output current limiting and overheating switching protection circuit, and does not have auxiliary circuits such as "pop" sound elimination, voltage stabilization bias and midpoint bias. Therefore, LM1877 only needs very few peripheral components to organize a high-quality HI-FI audio power amplifier.

The input signal of the double-core socket XS in Figure 9-68 is taken from the output hole of the multimedia sound card line. The signal is coupled to the 8th and 10th pins of IC1 through C4 and C11, and the output signal is coupled to the input end of IC2. R8 and R9 are the feedback resistors of the two channels.

Component selection and installation:

Production and debugging: