Making LM1875 DC negative feedback BTL power amplifier circuit

The LM1875 power amplifier circuit is simple, the tone is beautiful, and it has the tone of a tube amplifier. The power amplifier made with it can output power up to 25W at a voltage of plus or minus 25V.

In order to output greater power, it can be connected into a BTL circuit. The following circuit has an output power of more than 60W (8 ohm speaker) and is designed as a current negative feedback circuit with more beautiful sound. In addition, the owner of this board recommends connecting C11 and C11 in the picture. C21 is cancelled, and a capacitor is added to the input end (change C11 here). Change the circuit to a DC amplifier, the effect will be better

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After careful production, the amplifier's ear is attached to the speaker and basically no noise can be heard. The amplifier board is smaller than a business card. The 1875 is installed horizontally. All connections are routed under the aluminum plate, which is beneficial to improving the signal-to-noise ratio and the sound quality. It's very smooth and durable. Friends who are interested may wish to try it.