If you have the circuit foundation and hands-on ability, it is best to use high-quality low ripple switching power supply and linear power supply, that is, separate digital and analog power supply, with the least investment and the fastest effect.
If you don't have hands-on ability, but don't want to spend too much money, buy a vacuum tube output device similar to Le Fax X 10D to make the tone softer, and you can get certain results below 1000 yuan.
If you have money but don't know technology, you'd better buy two kinds directly. An imported R2R D/A converter, commonly known as a decoder, must remember that it is R2R, and it is not cheap, starting at more than 20,000 yuan; In addition, buy a digital shaper with prism sound, which can be bought at a cheap price of five or six thousand; Then the DVD is connected with digital shaper, and then connected with R2R decoder.
The last one is to give advice that you know technology and are not blind and arrogant. Keep your 10,000-yuan DVD player, eliminate the CD, use the DVD audio disk, and smash the CD directly into slag.
Having said that, I hope that friends who have pure audio original DVD BD can contact me!