* Circuit design: The board adopts an integrated design, onboard BT module, onboard radiator, onboard rectifier and filter, and onboard 1237 protection circuit. The wiring is simple and there is no need to worry about interference. This board is a UPC1342V push high-power tube structure, the circuit is simple, the quiescent current of the final high-power tube is adjustable, and it can output Class A sound; the circuit adopts a dual-channel design, the layout is clear, and the power supply and protection circuit are relatively far away from the amplifying circuit Remote, and added a BT 5.0 module, which is manually controlled by the relay and the switch in the middle of the panel.
* Background description: UPC1342V is a HIFI-level driving module developed by NEC in the 1990s. Its input stage uses a relatively classic PNP differential amplifier structure. The frequency response range of the circuit reaches 900K, which is difficult to achieve even with ordinary discrete component circuits. At this level, the chip protection part is very complete, and there is little damage without extreme conditions. It has high output power, strong control and high cost performance. Class A static current can be adjusted, the sound is thick, the sound is very durable, the dynamics are very strong, and the low frequency is good; it is 3-4 grades higher than the LM3886.
* Core circuit: Following the excellent broadband low-distortion 50w drive circuit UPC1225H, NEC has launched a new generation of audio driver IC-UPC1342V in order to meet the requirements of high power. This IC has all the advantages of UPC1225H and basically the same peripheral circuit. , Its output voltage deviation is smaller (±5mV), the voltage adaption range is wider (±20～±70V), and the driving power is more abundant. It can be called the IC of choice for home-made power amplifiers.
* Output power: Depending on the power supply voltage and speaker impedance, the output power is 20-150w; when AC35v is supplied, it can output 100w*2/8 ohms, 150w*2/4 ohms