Op275: Bolder than 5532, better resolution, lower frequency and better sound field. You can buy a patch to polish the sound card (especially innovative), which can improve the hard and cold situation of digital sound.
EL2244: The timbre is neutral, the sound stage is wide, the high frequency is ok, and the intermediate frequency music tastes bad. Some people say that the resolution is very high, in fact, because the low frequency is not very sensitive, the medium frequency is fine, and the high frequency is prominent. It's hard to use.
LT 1057: the extension at both ends is good, and the speed, dynamics and resolution are also good. It's a cool color, and the music seems to have an out-of-touch taste, which makes you listen quietly, but you can't lift your passion for music.
AD827: Very good ductility, high resolution, gorgeous high frequency, pure intermediate frequency, good dive and strength at low frequency. The sound stage has been extended to the front, back and left, with a concave-convex feeling (stronger than other operational amplifiers). It's fast and dynamic, and it feels great. This operational amplifier is really refreshing after its initial replacement. However, after listening for a long time, I also found many problems. Although the three zones of 1 and sound stage are very wide and full of momentum, the structure is a little loose and not tight enough, and the vocal part is average. Sometimes, when the music is full of energy, the vocal part will be submerged by the soundtrack. Not delicate enough, it belongs to passion but tenderness, and the music taste is not enough. But many people like this style. Of course, it's ok to buy two for a change. According to my feeling, it should be suitable for watching DVD blockbusters with AV amplifier.
OPA2604: It feels like an upgraded version of 5532, which has been greatly improved in all aspects, with good analytical power, better musical taste and bolder. The audio floor is thick, a little rigid and has good comprehensive quality.
DY649: Compared with 2604, the resolution is better, the high-frequency part is slender and soft, the overtone is rich, the sound base is not as thick as 2604, it is very clear and meticulous, the music picture is extremely clear, and the vocal part is round and transparent, which has a sweet feeling. Vocal part (especially female voice) is its strength.
DY639: The integrity is slightly weaker than that of 649, but it is more bold and has a stronger bile taste.
DY669: It's not much different from 2604, and its voice is pure and rich.
AD7 12: Very good resolution, clear and unstained sound, very transparent feeling, delicate sound base and a little low frequency. It is a typical monitoring style. But maybe many people don't like the feeling of pure water, so it's better to add some monosodium glutamate, which is probably the reason why I played music production before. Accustomed to this pure monitoring taste, I am very interested.
AD7 12 (Golden Seal): I was curious for a moment and got the golden seal the next day. Compared with Taofeng, I feel that the resolution is better, the sound base is purer and thicker, and the dive of low-frequency bounce is enhanced. Sound stage has a good sense of positioning. At first, I felt that my voice was not as clear as Tao Yin, but I was taken aback. Later, after repeated comparison, it was found that the high frequency of pottery seal was blunt, straightforward, full of sound details and bright sound, and there was such a feeling that gold seal was more resistant to listening. However, it is not recommended, because we can't find the disassembled parts of the gold seal now, so we need 75 yuan to buy a brand-new one, and we can buy a better model at this price.
AD797: Dongdong, which is worth trying, has a kind voice. It was detained immediately after being tested at a friend's house.
Disassembling parts 45 yuan; I bought these things because of time. Other high-end products are 627,265,438+065,438+065,438+0 (RMB 65,438+000), DY2000 and AD927 (I don't think I've heard of them), especially the Golden OPA2604 highly recommended by a store (asking price: 200).
; Finally, talk about the test feelings:
1 the operational amplifier is still good, and it is simple and effective to play.
In fact, at the level of 2604, the indexes such as resolution, range and musicality are also quite good, and the high-end operational amplifier is very distinctive, mainly depending on its own musical taste;
I have been tested in several places, and different amplifiers have different feelings. It seems that the circuit design is still the most important. My friend's English CD player has a good sound. It is made up of eight 5532s.
; 4 collocation is very important. I have a Spark CD player and an AD 10 earphone (heavy sound dyeing), which is muddy, thick and harsh. Usually there is no smell. It has been idle for a long time, so I tested the operational amplifier one by one and dismantled it all night. The last two 2604 CD players were replaced by DY649, and the earphone 5532 was replaced by 7 10. It feels like a new pair of headphones.
I borrowed a friend's K50 1 and tried it. I feel that the combination of 827+DY649 is the best.
; I have always wanted to find a higher-grade operational amplifier and try better results, because this feeling will lead to more energy and RMB. Hehe, I'd better not.
Low level operational amplifier JRC4558. This kind of operational amplifier is mostly used in low-end machines. Now it is considered to be super bad, because the sound is too bright and the burr is very strong, so it is the worst one compared with other audio operational amplifiers. However, it is still widely used in China for the time being, and many amplifiers whose cost is in 400 yuan or 500 yuan are still selected, because considering the cost and actual effect, it is not necessary to choose operational amplifiers with quality above 5532. For some computer active speakers, its coping ability is more than enough.
The emperor in the play. If someone hasn't heard its name, it's not a sound lover. NE5532, once known as the king of operational amplifiers, is also known as the four famous operational amplifiers with LM833, LF353 and CA3240, but now only 5532 is used the most. Now 5532 is mainly produced in Taiwan Province Province, the United States and Philips, and also in Japan. 5532 was originally a product of American SIGNE company, so American products with big S logo have the best quality. Genuine products on the market should be sold above 8 yuan. Since SIGNE was acquired by Philips, all the 5532 trademarks produced are trademarks of Philips, and the quality is equivalent to the original products, only 4-5 yuan. The quality produced in Taiwan Province Province is slightly worse, and the price is also the most convenient. You can buy it for two or three yuan. Like the 4558, the package of the NE5532 is also a DIP8-pin dual operational amplifier (the functional pins are shown in the figure), and the inside of the 5532 is a JFET (junction field effect transistor structure). The overall sound features are warm and delicate, with strong driving force, but the high notes are slightly rough and the low notes are fat. In the past, many people thought it was a little "bile flavor", but now it is much more than it, and it is relatively less prominent. 5532 has a wide voltage adaptation range, and can work normally from plus or minus 3V to plus or minus 20V. Although it is an old operational amplifier, it is still considered to be the most cost-effective operational amplifier for audio. It is a civil operational amplifier, which is adopted by many low-end power amplifiers. But there are too many fake NE5532 or industrial products that are not used for audio. Because the pin function of 5532 is the same as that of 4558, some unscrupulous merchants erase the letters of 4558 and print the words 5532 as 5532. Generally, the appearance is rough, the printing is easy to erase, and people with little experience can distinguish it. It is said that 8mA warm current is the authentic audio.
NE5532 has two brothers, NE5534 and NE5535. 5534 is a single operational amplifier. Because it separates a single operational amplifier and there is no interaction between the two operational amplifiers, the timbre is not only soft, warm and delicate, but also has a good musical taste. Its voltage adaptation range is also very wide, and the voltage as low as plus or minus 5V can keep good working condition. Because the famous BGW- 150 power amplifier in the United States used 5534 as the voltage excitation, the positive power supply voltage was deliberately higher than 0.7V, which forced its output tube to work in a more perfect class A state, and further improved the sound quality. So now it is generally believed that the sound quality of the positive power supply above 0.7V will be better ... The pin function of 5534 is shown in the figure, and the price is equivalent to that of 5532. NE5535 is an upgraded product of 5532, which is characterized by simpler internal circuit and completely complementary output stages. The conversion rate is higher than 5532. However, there is a disadvantage that the noise is large, the frequency band is not wide enough, and the bottom voltage performance is not good enough, so the effect is not as good as that of 5532 when it is used for analog filtering. But when the working voltage is greater than or equal to 15V, the music taste will be better than that of 5532, so its price is two or three yuan more expensive than that of 5532, and the pin function is the same as that of 5532.
AD827 dual op amp. This is a relatively new product of the advertising company. It was originally designed for video circuits, so its gain bandwidth reaches 50MHZ and SR reaches 300V/us. Like EL2244, it is the top product of voltage feedback dual operational amplifier on the market at present, and the general operational amplifier is far behind. Its high-frequency operation is transparent, its low-frequency bounce feeling is outstanding, its performance index and actual listening feeling are better than many other similar products, and its sound quality is also described by some people as impeccable. And it still has excellent performance under the power supply of plus or minus 5V. But its price is also slightly more expensive, more than 30 yuan. Foot position function is the same as 5532.
Dual op amp OP249. Operational amplifier is a product of American PMI company. The manufacturer claims to replace OP2 15, LT 1057 and other operational amplifiers. LT 1057 is a dynamic Leng Yan with high resolution and beautiful timbre, which is suitable for matching with Toshiba's warm-colored famous pipes. On the other hand, OP249 is different. Its input stage adopts JFET, which is characterized by neutrality, impersonality, balance, naturalness and accurate sound, thus embodying the true meaning of HIFI. Plastic packaging only needs 15 yuan, and ceramic packaging costs more than 30 yuan, which is very cost-effective. But friends who have a preference for timbre may not like it very much.
Dual operational amplifiers OP275 and OP285: also products of PMI company, the internal circuit adopts a mixed structure of two stages and JFET. Its timbre is very individual, with low noise, well-defined sound, high resolution and soft voice. The intermediate frequency has the characteristics of softness and courage, and the sound is close. Moderate price and stable performance. Suitable for rubbing CD, decoder or amplifier with thin and rough sound. Their package forms and pin functions are the same as those of 5532. OP275 current market price 10 yuan, OP285 15 yuan.
Top op amp OPA627. The OPA627 of BB Company is by far the most advanced operational amplifier, and it also adopts the input mode of field effect transistor. Its timbre is warm and charming, but the price is simply frightening, reaching 150 yuan. Therefore, non-top machines generally do not use such expensive operational amplifiers, and whether the performance can reach this price is also a matter of opinion. However, enthusiasts who have heard of OPA627 agree that they can't make AD827, LT 1057 and so on.
OPA604 and OPA2604 release bile flavor. These two operational amplifiers are products of Burr Brown, OPA604 is a single operational amplifier, and OPA2604 is a dual operational amplifier. They are all special operational amplifiers specially designed for audio. They are mellow and mellow in tone, warm and neutral, and have a strong bile taste. They are regarded as the operational amplifiers with the most tone of electronic tubes. At that time, the price was not low, but it was still chosen by many audio enthusiasts as the object of motorcycle upgrading. At present, the prices of these two operational amplifiers are reasonable. Opa604 from 25 yuan, opa 2604 40 yuan. It is a good choice for enthusiasts to ride motorcycles.