TDA1521 Dual-Channel HiFi Amplifier Board

This circuit uses fast recovery diode rectification, Rubycon large-pond filter, ELNA Brown God 2 decoupling capacitors, and Vishay MKP signal coupling capacitors for the signal input, with capacitance approximately double that of the official circuit, resulting in more elastic low frequencies. The output anti-vibration network and 0.1uf power supply filter decoupling film capacitors are all German MKP film capacitors, and the output capacitors are Nichicon FW series... During this routing, the power supply section featured extensive copper plating to reduce ground impedance. The signal section used a floating ground, with separate and independent routing from the audio output ground and anti-vibration network ground, ultimately converging to a single power ground point. Various sizes of mounting holes were designed for each capacitor, allowing easy installation of different package sizes from various brands. I've designed and installed several TDA1521 circuits before, but with this careful design and layout, and by using high-end components, it produced sound immediately after installation. The circuit had no problems, and there was almost no background noise when connected to speakers. Listening with an audio source, it felt like I had a completely new sound system! Not only was the bass more elastic, but it was also very pleasant to listen to for extended periods. Especially when you listen to it late at night when it's quiet, the singer's lip and sibilance sounds and breathing sounds are clearly visible. In short, the details are greatly improved compared to the previous version! My evaluation of this thing is: I don't want to turn it off!