DAC digital-to-analog conversion post-buffer low-pass filter circuit

The operational amplifier OPA627 used in the first-level low-pass buffer is integrated with a single operational amplifier. The frequency can reach up to 16MHZ and the conversion rate can reach 55V/us. All parameters are quite good. The second stage uses dual operational amplifier OPA2134, which is very bold. This circuit is mainly relatively simple and easy for beginners to make. As long as the components used are better selected, your CD player can be completely transformed. The negative input terminal of U1 (i.e. pin 2) can be connected to the output terminal of the DAC digital-to-analog decoding. These two ICs are a bit expensive. Friends with average economic conditions can choose other operational amplifier ICs with inputs composed of field effect transistors, such as the mid-range OP275. The low-priced ones can choose LF353 or single operational amplifier LF356 (note: the LF series only has The sound of NS is passable, and others will not be considered). TL082 or TL072 also fall into this category, but when used here, there is no need to adjust the machine. Personally, I think you should use at least the national semi-finished LF353.

Friends who are financially capable and have high requirements can switch to AD 827 or AD 712. It is better to choose a higher frequency for the first stage op amp.

NE5532 or other op amps that do not use field effect transistors as inputs cannot be used in the first-level buffer, because high impedance input is required, otherwise signal loss will occur. (Also: Now when I listen to 5532, the sound sounds rough and stiff, so I basically don’t use it anymore)