Low-grade op amp JRC4558. This kind of op amp is the most used by low-end machines. It is now considered to be super bad, because its sound is too bright and has a strong burr, so it is the worst kind compared to other audio amplifiers. However, it is still widely used in China for the time being. Many power amplifiers of four or five hundred yuan still choose to use it. Because of the cost and the actual effect, it is not necessary to choose an operational amplifier with a quality of more than 5532. For some computer active speakers, its coping ability is still more than enough.
The emperor of op amp 5532. If anyone has n’t heard of its name, it ’s not yet a sound enthusiast. This NE5532, which was known as the op amp emperor, was the four old-named op amps together with LM833, LF353, and CA3240, but now only 5532 is the most widely used. 5532 is now mainly produced separately from Taiwan, the United States and PHILIPS, but also from Japan. 5532 was originally a product of the American SIGNE company, so the best quality is the American product with the big S logo. The authentic one on the market should be sold for more than 8 yuan. Since SIGNE was acquired by PHILIPS, the 5532 trademark produced uses PHILIPS The quality of the trademark is the same as the original product, only 4-5 yuan. The quality of production in Taiwan is slightly worse, and the price is also the most convenient, and two or three pieces can be bought. The package of NE5532 is the same as 4558, both are DIP8 pin dual op amps (the function pins are shown in the figure). The sound characteristics are generally warm and delicate, with strong driving force, but the treble is slightly rough and the bass is fat. Many people used to think that it had a little "gut taste", but now there are many more guts than it, which is relatively less prominent. The Voltage adaption range of 5532 is very wide, from positive and negative 3V to positive and negative 20V can work normally. Although it is an older op amp model, it is still considered to be the most cost-effective op amp for audio. It is a kind of op amp that is civilianized, and is used by many mid-range power amplifiers. However, there are too many counterfeit NE5532, or non-audio industrial products. Because the pin function of 5532 is the same as that of 4558, some unscrupulous merchants also erase the letter 4558 and print 5532 as 5532. The printing is easy to erase, and people with a little experience can recognize it. It is said that the warm current of 8mA is the authentic audio frequency 5532.
NE5532 also has two brothers NE5534 and NE5535. 5534 is a single op amp. Because it separates the single op amp, there is no interaction between the two op amps, so the sound is not only soft, warm and delicate, but also has better music taste. Its voltage adaptation range is also very wide, and the voltage as low as plus or minus 5V can also maintain a good working state. When the famous American BGW-150 power amplifier used 5534 as the voltage excitation, the positive power supply voltage was intentionally higher than 0.7V, forcing its output tube to work in a more perfect Class A state, which further improved the sound quality. It will be better if the positive power supply is higher than 0.7V. See the pin function of 5534 (picture), the price is equivalent to 5532. The NE5535 is an upgraded product of 5532, which is characterized by a simpler internal circuit and a fully complementary structure for the output stage. 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 performance is not good enough when the bottom voltage is working, so the effect when used in analog filtering is not as good as 5532. However, when the operating voltage is greater than or equal to 15V, it is used as a linear amplifier circuit. The musical taste will be better than 5532, so its price is two or three yuan more expensive than 5532, and its pin function is the same as 5532.
Double op amp AD827. This is a newer product from AD. It was originally designed for video circuits, so its gain bandwidth reaches 50MHZ and SR reaches 300V / us. It is the top of the current voltage feedback dual op amp on the market like EL2244. Goods, general op amps are hard to see. Its high-frequency operation is transparent, its low-frequency bounce is superior, its performance index and actual hearing sense are better than many other similar products, and the sound quality is described as impeccable by some people. And it still has excellent performance under the power supply of plus or minus 5V. But its price is also slightly expensive, more than 30 yuan. The pin function is the same as 5532.
Double op amp OP249. The op amp is a product of the American PMI company. The manufacturer claims to replace the OP215, LT1057 and other op amps. The LT1057 is a kind of large dynamic, high resolution, cool and beautiful tone. Suitable. The OP249 is different from it. The input stage uses JFET. The main feature is neutral, no personality, balanced sound, natural and accurate, so it reflects the true meaning of HIFI. The plastic package is only 15 yuan, and the ceramic package is more than 30 yuan, which has a high cost performance. But friends who have a preference for timbre may not like it.
Dual op amps OP275, OP285: They are also products of PMI, and the internal circuit uses a dual-stage and JFET hybrid structure. Its timbre is very individual, with low noise, clear voice contour, high resolution, and soft sound. The mid-frequency has the characteristics of a soft and moist tube, and the voice is close. The price is moderate and the performance is stable. It is suitable for playing CDs, decoders or amplifiers with thin and rough sound. Their packaging and pin functions are also the same as 5532. OP275's current market price is 10 yuan, OP285 15 yuan.
Top op amp OPA627. BB's OPA627 is by far the most high-end op amp, and it also uses a field effect tube input method. The sound is warm and charming, but its price is scary, reaching 150 yuan, so it is generally not the top machine. Such an expensive op amp is generally not used. Whether the performance can reach this price is also a matter of opinion, but enthusiasts who have heard of OPA627 all agree that AD827, LT1057, etc. are simply not comparable.
Opaque OPA604 and OPA2604. Both of these op amps are products of Burr Brown, OPA604 is a single op amp, OPA2604 is a dual op amp. They are all dedicated op amps specially designed for audio. They are full-bodied, round, neutral, warm, and bold. They are known as the most operational amplifiers with tube sounds. At that time, the price was not low, but it was still selected by many audio enthusiasts as a target for upgrading the machine. Now the prices of these two op amps are more reasonable, OPA604 is 25 yuan, OPA2604 is more than 40 yuan, and enthusiasts use motorcycles as a good choice.
The emperor of op amp 5532. If anyone has n’t heard of its name, it ’s not yet a sound enthusiast. This NE5532, which was known as the op amp emperor, was the four old-named op amps together with LM833, LF353, and CA3240, but now only 5532 is the most widely used. 5532 is now mainly produced separately from Taiwan, the United States and PHILIPS, but also from Japan. 5532 was originally a product of the American SIGNE company, so the best quality is the American product with the big S logo. The authentic one on the market should be sold for more than 8 yuan. Since SIGNE was acquired by PHILIPS, the 5532 trademark produced uses PHILIPS The quality of the trademark is the same as the original product, only 4-5 yuan. The quality of production in Taiwan is slightly worse, and the price is also the most convenient, and two or three pieces can be bought. The package of NE5532 is the same as 4558, both are DIP8 pin dual op amps (the function pins are shown in the figure). The sound characteristics are generally warm and delicate, with strong driving force, but the treble is slightly rough and the bass is fat. Many people used to think that it had a little "gut taste", but now there are many more guts than it, which is relatively less prominent. The Voltage adaption range of 5532 is very wide, from positive and negative 3V to positive and negative 20V can work normally. Although it is an older op amp model, it is still considered to be the most cost-effective op amp for audio. It is a kind of op amp that is civilianized, and is used by many mid-range power amplifiers. However, there are too many counterfeit NE5532, or non-audio industrial products. Because the pin function of 5532 is the same as that of 4558, some unscrupulous merchants also erase the letter 4558 and print 5532 as 5532. The printing is easy to erase, and people with a little experience can recognize it. It is said that the warm current of 8mA is the authentic audio frequency 5532.
NE5532 also has two brothers NE5534 and NE5535. 5534 is a single op amp. Because it separates the single op amp, there is no interaction between the two op amps, so the sound is not only soft, warm and delicate, but also has better music taste. Its voltage adaptation range is also very wide, and the voltage as low as plus or minus 5V can also maintain a good working state. When the famous American BGW-150 power amplifier used 5534 as the voltage excitation, the positive power supply voltage was intentionally higher than 0.7V, forcing its output tube to work in a more perfect Class A state, which further improved the sound quality. It will be better if the positive power supply is higher than 0.7V. See the pin function of 5534 (picture), the price is equivalent to 5532. The NE5535 is an upgraded product of 5532, which is characterized by a simpler internal circuit and a fully complementary structure for the output stage. 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 performance is not good enough when the bottom voltage is working, so the effect when used in analog filtering is not as good as 5532. However, when the operating voltage is greater than or equal to 15V, it is used as a linear amplifier circuit. The musical taste will be better than 5532, so its price is two or three yuan more expensive than 5532, and its pin function is the same as 5532.
Double op amp AD827. This is a newer product from AD. It was originally designed for video circuits, so its gain bandwidth reaches 50MHZ and SR reaches 300V / us. It is the top of the current voltage feedback dual op amp on the market like EL2244. Goods, general op amps are hard to see. Its high-frequency operation is transparent, its low-frequency bounce is superior, its performance index and actual hearing sense are better than many other similar products, and the sound quality is described as impeccable by some people. And it still has excellent performance under the power supply of plus or minus 5V. But its price is also slightly expensive, more than 30 yuan. The pin function is the same as 5532.
Double op amp OP249. The op amp is a product of the American PMI company. The manufacturer claims to replace the OP215, LT1057 and other op amps. The LT1057 is a kind of large dynamic, high resolution, cool and beautiful tone. Suitable. The OP249 is different from it. The input stage uses JFET. The main feature is neutral, no personality, balanced sound, natural and accurate, so it reflects the true meaning of HIFI. The plastic package is only 15 yuan, and the ceramic package is more than 30 yuan, which has a high cost performance. But friends who have a preference for timbre may not like it.
Dual op amps OP275, OP285: They are also products of PMI, and the internal circuit uses a dual-stage and JFET hybrid structure. Its timbre is very individual, with low noise, clear voice contour, high resolution, and soft sound. The mid-frequency has the characteristics of a soft and moist tube, and the voice is close. The price is moderate and the performance is stable. It is suitable for playing CDs, decoders or amplifiers with thin and rough sound. Their packaging and pin functions are also the same as 5532. OP275's current market price is 10 yuan, OP285 15 yuan.
Top op amp OPA627. BB's OPA627 is by far the most high-end op amp, and it also uses a field effect tube input method. The sound is warm and charming, but its price is scary, reaching 150 yuan, so it is generally not the top machine. Such an expensive op amp is generally not used. Whether the performance can reach this price is also a matter of opinion, but enthusiasts who have heard of OPA627 all agree that AD827, LT1057, etc. are simply not comparable.
Opaque OPA604 and OPA2604. Both of these op amps are products of Burr Brown, OPA604 is a single op amp, OPA2604 is a dual op amp. They are all dedicated op amps specially designed for audio. They are full-bodied, round, neutral, warm, and bold. They are known as the most operational amplifiers with tube sounds. At that time, the price was not low, but it was still selected by many audio enthusiasts as a target for upgrading the machine. Now the prices of these two op amps are more reasonable, OPA604 is 25 yuan, OPA2604 is more than 40 yuan, and enthusiasts use motorcycles as a good choice.
The 18650 (18mm diameter and 65mm length ) battery is a size classification of lithium-ion batteries.
It is the same shape, but a bit larger than a aa battery.
AA batteries by comparison are sometimes called 14500 batteries, because they have a 14mm diameter and 50mm height.
18650 discharge, lc 18650, 19650 battery
Shenzhen Powercom Electronics Co., Ltd. , https://www.expowercome.com