Discussion for Collocation of Integrated Operational Amplifier and Integrated Power Amplifier

Operation amplifier and integrated power amplifier are two types of devices that elementary enthusiasts and student enthusiasts like to use. They have many varieties, different performance, and different sound quality and timbres. How to match and combine the above two types of devices to make the best use of them, give play to their respective advantages, and create preferential performance-price ratio is a problem worth discussing.

Although the author has accumulated some experience in the course of fever for several years, he also has a considerable number of audio devices in stock. Among them, there are many integrated operational amps and integrated power amps, including the early fever operational amps LM833N, NE5532N, NE5535N, and the recent hot OP275G, LT1057, AD827JN. The integrated power amplifier is some very well-known models, such as the TDA1514A, LM1875T, LM1876TF, LM3886TF and the early TA2030A. Of course, integrated blocks such as JRC4558P, TL072 and TDA2030 do not need to be studied because their performance is not yet "fever" level.

The above integrated power amplifier is a finished board, the components on the board, the process is still relatively sophisticated, and they are very simple. For the above several operational amps, because they are standard double operational amps, only one front buffer amplifier board is used, that is, the AD827 used in the "Fine Pin1876" in the "Electronic News" on June 13, 1999. The components are very sophisticated: DALE W gold film resistor, WIMA, ELNA capacitor, APLS potentiometer, silver plated double panel, the process is also very sophisticated. The author removed the AD827 and replaced it with a 24K gold-plated outlet.

In the power supply, the operation amplifier uses the servo power supply ±15V, and the power amplifier uses the power supply mode of large ring bull, double bridge rectification, large pond and small pond electrolysis in turn.

At the same time, the author also invited several like-minded burning friends to review together. The time of listening is still chosen after seven o 'clock in the evening, in order to have a better environment. The equipment used is Xiamen third generation DVD8058A and Huiwei Duxi 21C, and the software is still familiar with saxophone, CAI Qin old songs, Hugo I and so on.

I love 1876, let it take the lead, in turn for it to replace the above six amPs. Of course, the 827+1876 combination previously used by the author has priority in listening and has been unanimously praised. The medium and high frequency of this match has a strong musical flavor, smooth, balanced, natural, warm, and makes people intoxicated, and the low frequency is also clean and relaxed. The combination of OP275+1876 is slightly worse in the sense of high frequency extension, the low frequency is slightly fuzzy, and the medium frequency is still excellent, and the overall feeling is slightly lower than the AD827, which is the optimal choice in the pursuit of cost performance. Although the LT1057 is a well-known name, it is not suitable for 1876, the problem is in the timbre, which always gives people a "cold" and "thin" feeling. LM833 is similar to NE5532, the sound color is warm, but the high frequency burr is strong, the low frequency can not be stopped, and the noise of 5532 is slightly larger. In NE5535, a channel was seriously distorted after replacement, and it was estimated to be damaged, so the comparison was withdrawn. In summary, for the power amplifier LM1876, the AD827 can achieve high performance, and the OP275 has a high cost performance.

Next we switched to the LM3886, which felt very similar to the 1876, but with more power. Still feel better with the AD827. OP275, NE5532, LM833 these three models are not much different after use, but the low frequency of OP275 is better, which may be related to its 22V/ms conversion rate. The LT1057 still reflects the characteristics of the heavy metal, this combination makes people feel good for home theater, dynamic, powerful. In particular, the [Gate of Kiev] section of "Picture Exhibition" in Hugo I is very magnificent.

In the well-known power amplifier LM1875, the AD827 is not very prominent, the LT1057 is a shock, the overall balance, moderate tone, high and low frequency rich, the musical details are also handled just right, especially Kenny G Sax's "Spring Breeze" background music triangle accompaniment, particularly clear and pleasant, silk. The NE5532 works well with the OP275 and the 1875. Especially 5532, can be described as cheap, it has the same conversion rate with 1875, no speed "bottleneck" problem, make the best use of it, it is recommended, LM833 is slightly worse.

For 1514A, because it is a "cold and beautiful" type power amplifier, it is difficult to get along with LT1057, and other AD827 and OP275 are better. NE5532, LM833 can also be matched with it, but the medium frequency is always unsatisfactory. Overall consideration, 1514A, OP275 can be preferred, although there is no outstanding place, but also normal.

After the appearance of TDA2030A, although it is yesterday's day, but the community has a large number of computers, and a considerable number of active speakers still use it, our suggestions can be used as a reference for 2030A users. We recommend NE5532 or LM833, they are sufficient with 2030A, there is no need to pursue the other three. In terms of sound, the difference is minimal.