The board powerful bass， treble， clear and melodious. TDA2030A replaced LM1875 also performed well， if you want to replace the LM1875 recommended for large heat sink. TDA2030A only have five pins: Positive power and negative power， positive input， reverse input and output. TDA2030A and negative heat sink is connected with a dual power supply， heat sink and ground do not short-circuit， or immediately burned TDA2030A.