Low power amp circuit diagram made with NE5532

Speaking of low-power amps, I have to mention the NE5532 of the 20th century op amp, which has appeared in countless excellent preamplifiers and tuning circuits. The intermediate frequency is warm and delicate, bold and cost-effective! Until today we can easily find it in some low-end audio products. Because of its small size and simple circuit, it is the first choice for practical and low-input hands-on. Because the NE5532 has been in existence for several years since its introduction, everyone is very familiar with its circuit and has a variety of gameplay. The amp described here is characterized by simplicity, low power, and a focus on the manufacturing process.
First, the principle analysis

The NE5532 is a typical bipolar input operational amplifier. There are many versions of the low-power circuit composed of a single NE5532. I have modified and modified the various circuit diagrams by constantly comparing and thinking, and finally determined the schematic (Figure 1). The magnification is controlled by R3(R4) and R5(R6). Theoretically, if R3(R4) is 1kΩ and R5(R6) is 100kΩ, the magnification is 100 times, but for the amp, This will cause self-excitation, and even if it can really reach 100 times, the effect is not good, so this circuit is best not to be adjusted to 100 times when used in the pre-stage. Of course, for the amp to be 2 to 3 times, the negative feedback can be moderate, the sound quality is soft, clear and transparent, but the magnification can not be too small, otherwise it will affect the sound quality, you can repeatedly debug to achieve your own satisfactory results. The author sets R3 (R4) to 1kΩ and R5 (R6) to 20kΩ, which is 2 times. C5 (C6) is the ground path of the input loop. It should be increased when used in the amp circuit. The value in the schematic is 22 uF, but it should be increased to 100 uF for this amp.

It is worth mentioning here that the power supply problem, if you are using the regulated power supply, pay attention to the filter of the regulated power supply, because the circuit itself is very simple, then the selection of components is more critical, it is recommended When selecting materials, try to choose components with better quality.