Continuously surpassing the peak of the climb, QUAD 909MONO post-amplifier
Follow WeChat Download Audiophile APP Follow the audiophile class related suggestion Enthusiasts who pay attention to the details of music know that the pre-amplifier plays a role in the audio circuit ... The core part of the circuit consists of a DC tone control IC, an NPN transistor and ... '+ data.data.username +' '; dom + =' Neckband Earphones,Neck Earphones,Best Neckband Earphones,Wireless Neckband Earphones Dongguang Vowsound Electronics Co., Ltd. , https://www.vowsound.com People say that there is a fog city in the UK-London, so the audio equipment produced in the UK will also have the characteristics of the fog city "with D Mongolia check". If this is put 5 years ago, maybe I will agree, but nowadays The new British equipment is no longer the case. Look at Le Fuhao, an old-fashioned speaker manufacturer with a history of more than 70 years. Now the speakers such as OPUS , EVO , Diamond 9 series and so on are available. Which one still feels like a flower in the fog? I have heard all of them. These products not only have excellent clarity, but also retain the traditional excellent technology, such as curved cabinet, broadband dome soft film midrange technology, bulletproof fiber diaphragm, etc. Modern leading technology makes these products with excellent quality and at the same time cheap and beautiful !
The well-known British QUAD
The nearly 70- year-old British audio manufacturer QUAD (national capital) also has a similar development process, and is also active on the world's audio stage with continuously innovative technologies and products.
Chen Weiliang: The famous British manufacturer QUAD not only produces well-known electrostatic speakers. In fact, QUAD has invested effort and technology in manufacturing amplifiers and amplifiers as early as 1936 when it was founded by Pteer Walker . It has designed very high-quality amplifiers, including vacuum tube and transistor design It has always been welcomed and loved by the majority of enthusiasts ! Early products such as QUAD â… , QUAD â…¡, 306 , 405 , 606 , 707 , 909, etc., whether it is a transistor or a tube, the design and manufacture are very good!
Xue Ming: With his extraordinary thinking and creativity, Mr. Peter Walker makes the audio products produced by QUAD always look like creative artworks, and many of them have become collectors' items for audio enthusiasts.
Chen Weiliang: Yes, the previous masterpieces QUAD II 40 mono 40W tube and QUAD II Class mono 15W tube amplifier and 909 stereo amplifier, senior audiophiles and Philharmonics are bound to be familiar! The adaptability of collocation is very wide, many friends are very easy to match different types of pre-levels , and the sound performance is natural mellow, harmonious and balanced, pleasant and listening! The characteristics of these QUAD amplifiers have been affirmed by Philharmonics!
Xue Ming: Peter Walker has a wealth of knowledge in electroacoustics, and the requirements for sound reproduction are very high, so the products he designed are all known for their timbre accuracy, which also makes QUAD products always popular and award-winning countless. One of the most proud of in 1978 With Current Dumping (current pour) amplification technology receiving the prestigious award the status of "Queen of Science and Technology Achievement Award", which established Peter Walker and Quad significant contributions made in the audio industry.
Weiliang Chen: Because Pteer Walker has always attached great importance to the requirements of equipment quality, simple and direct circuit design and excellent selection of materials are the evergreen signs of QUAD amplifiers! Not only is the sound beautiful, but also reliable and durable, many friends still use the QUAD amplifiers of the 1950s and 1960s, including myself, and there are no less than four old and new QUAD equipment in the test room at home!
Xue Ming: Peter Walker passed away on December 10 , 2003 , but QUAD 's new products continue to reach new heights. In 2002 and 2003 won the British authoritative audio magazine " What Hi Fi ?" 》 Quad 11L , the bookshelf speaker that selected the best product of the year ( QUAD ) , stands for Quad under the guidance of the new generation and still shines. After all, the same model has won this award for two consecutive years. In " What Hi Fi ?" "Is very rare.
Weiliang Chen: Very few amplifiers or speakers produced by other brands in different eras in history can make amazing masterpieces! And QUAD did it!
Xueming: As for the electrostatic speaker Peter Walker studied all his life, it is another classic of Quad . The naturalness and transparency of its timbre are still unforgettable. And now, the excellent technology of electrostatic speakers still makes his products flourish everywhere. Like ESL - 988 / 989, these two products not only continue the Delay Line Concentric Ring technology ( the electrodes are arranged in a concentric shape, but also from inside to outside) Set a very short time delay, so that the working time of the electrode produces a slight time difference from inside to outside, and at the same time, the principle of using a magnetic field between the electrodes to drive the diaphragm to produce sound, thereby generating a point sound source that radiates sound from the center to the outside. This method is like throwing a stone into a calm lake, the generated waves will evenly spread to the surroundings, and the sound of the instrument is also a bit to the surface. Therefore, this concentric circle method is currently the most natural sound In this way, the method of increasing the diaphragm up and down is used to effectively improve the low-frequency response, thereby making the sound effect of the electrostatic horn more perfect.
People who are not astonishing look "stunned"
Xueming: QUAD has never had an exaggerated design and a strong body, and its actions are all in pursuit of reasonable and high cost performance. Many QUAD users will be fascinated by her appropriately ingenious process design and revel in the accurate sound reproduction. QUAD 's flagship 909MONO is unremarkable in front of unfamiliar friends, but this is a name we want to introduce here.
Weiliang Chen: QUAD 909MONO Block transistor mono power amplifier, each 300W output! Awesome ...
Xueming: To talk about the QUAD 909MONO post-amplifier, we must first talk about its predecessor 909 Stereo . As the name suggests, 909 Stereo is a stereo amplifier, 909MONO is mono. From the appearance point of view, except the words on the panel can clearly distinguish the two models, you can only observe the terminals behind the machine. 909Stereo has two sets of speaker wire terminals and two RCA signal input terminals, and QUAD 909MONO is just right. Cut in half.
Weiliang Chen: But after opening the case, it looks completely different from 909 Stereo ! Transformer nearly fills the entire space within the machine, the big 1.5cm diameter than 909Stereo transformer, a staggering 14cm, height high 2cm, but also large power more than doubled! According to the factory, the current of the whole machine is 1.5 times greater than that of 909 Stereo ! The power crystal is exactly doubled, and other connecting wires are all used in more advanced colors. The two rows of circuit boards erected in the machine are also special varieties. They continue to use QUAD ’s current dumping for decades ( Current Dumping ). "Type" circuit, compared with some Big Mac Power amps , the 909MONO is not very conspicuous, but it is solid and durable , and the small case contains 12 carefully selected MOSFET iron shell tubes and three high-quality large Fast capacitance of the pond! Class AB reaches 300W at 8 ohm output! There is no ingenious design on the whole , everything is practical and reliable.
Xueming: Everyone should pay attention here. The filter capacitor of the big reservoir used by 909MONO is a high-voltage product with a voltage resistance of 160V . Compared with the usual 50V or 63V withstand voltage used by transistor amplifiers, it is several times higher. The reason is QUAD . second stage is the famous "poured circuit current", the driving voltage of the circuit is almost the more common amplifying circuit 1 times, so using a high pressure natural products. The shell structure of the two amplifiers is exactly the same. The upper and lower covers are made of aluminum with a wall thickness of more than 3mm . The left and right sides are designed with ventilation holes and heat sinks. An aluminum plate is bent in the middle of the upper and lower end covers to form the front, left, and right housings, which play the role of sealing the cabinet and decorating. When the rear stage is actually assembled, it is not this aluminum plate that supports the upper and lower end covers, but the large radiators on the left and right of the machine. Well, in fact, the 909 amplifier uses the chassis as a radiator, and the heat dissipation effect is also very ideal. The two amplifiers work for a long time, and the temperature is only slightly warm. In 909 Stereo , the amplifying circuit boards installed on the two heat sinks are used to amplify the two left and right channels respectively, forming a 150W × 2 output. In QUAD 909MONO , the output circuit has been improved and adjusted to reach a channel output of 300W . I believe that with such a strong power output, few speakers can't push it.
Weiliang Chen: We have been playing 909 Stereo for many years and we know its strength, so we also have great confidence in the materials and design of 909MONO Block . Because of this, we decided to choose some of the most difficult to serve when listening to the 909MONO amplifier this time. To test it, the speakers of PMC , MBL , ATC , SCM150 , Dynah C4 , Weixin 6 , ESL - 989 static, Le Regal classic masterpiece, Aiden large flagship, B & W N801D , M40 after the rain, a total of 8 pairs of famous works.
The pre-stage uses the built-in pre-stage parts of QC - 24 , ARC SP - 11MK II, SF LINE - 3 , MBL6010D and 99CDP .
CD player: 99CDP , SONY SCD - 1 , LINN - CD12
Wire: Germany AA (power cable), Minli (signal, speaker cable)
Xueming: If you want me to use the shortest text to describe the characteristics of the 909MONO amplifier, I think I will use an 8- character description: strong, accurate, reliable, and cost-effective. In fact, these 8 words are also my playing audio . After listening to music for many years , I have summed up the requirements for the post-amplifier. Now QUAD 909Mono fully meets me.
Weiliang Chen: Since Quad 909 Mono Block is specially designed and manufactured for low-efficiency quiet speakers, when the above 8 pairs of today ’s prestigious large speakers are opened, the overall sound performance is very calm and natural, mellow and solid , control these speakers Very good. If you have never heard it before, you certainly can't imagine such an excellent effect!
Xueming: First of all, I will talk about what is "strong". My understanding of the function of the rear stage is to amplify the signal provided by the front stage or the source to provide sufficient driving force to drive the speaker to sound. This is the most basic function of the post-stage, so the output power has also become one of the important technical data of the post-stage amplifier. Under the same conditions, the greater the output power, the stronger the driving force, the more able to cope with complex audio signal changes. Just like the car we drive, the greater the power of the engine, the better the power performance of the car. The car can run faster or carry more load.
Of course, the power level does not mean that the performance is good or bad. The higher the output power of the post-stage amplifier, the higher the requirements for circuit design completion, component quality, heat dissipation performance, etc., as long as there is a certain aspect Defects will affect the safety and stability of the equipment. The same is true for automobile engines. The higher the power, the higher the requirements for sealing, lubrication and heat dissipation. In addition to the output power, the damping characteristics are also affected by the driving performance of the rear stage. A good rear stage amplifier often has a high damping coefficient. Just like the important index of the automobile engine in addition to the output power and output torque, under the same output power, The greater the torque, the better the control of the engine. The higher the damping coefficient of the amplifier, the better the control of the back electromotive force of the speaker unit, and the better the transient response performance. My example above is to illustrate that the greater the output power and torque of the post-stage power amplifier, the better the performance. But the better the performance, the more difficult the design, the higher the manufacturing cost, and the more expensive the price. This also shows that the 909MONO amplifier as the flagship post-stage of the QUAD transistor is because its performance is the best in its own products, but it is also the most expensive. From all indicators, 909MONO can be called powerful.
If the sound of the amplifier is good, the driving force is not enough. If the distortion rate is high, the previous efforts will be abandoned. The magnification of the post-stage amplifier is quite high. It needs to amplify the current of the milliamp level to tens of amps. Such a large enhancement is very easy to produce high distortion. However, QUAD 909MONO successfully controlled the distortion rate at a fairly low level through a mature circuit structure and carefully paired components, making the replayed sound authentic. This made me feel the meaning of accurate replay.
Just like listening to "Maeller's First Symphony", if there is no strong driving force, it is difficult to reproduce the huge and spectacular scene. Strictly speaking, 909 Stereo pushed ESL - 989 in the audition room of nearly 60 square meters. There are also good performances, but it is inevitable a bit nervous under extreme sound pressure. However, after changing to 909MONO , the enhancement of the driving force made the music scene suddenly loose and natural, more powerful and powerful, and even the elements of clarity, audio-visual separation, layering, etc. showed a higher level. There is no doubt that the degree of dynamic contrast is more intense, and the analytical power and lines of low frequency have made great progress. Under the similar structure and circuit conditions, the increase in power significantly improved the quality of the sound, clearly reproducing the complex parts and sound structure of "Maeller's First Symphony".
Another example is listening to "The First Drum in the World ". The powerful driving force of 909MONO has raised the performance of dynamic and low frequency to another level. I obviously feel that the drumming force is also 50 % stronger. , And the details and texture of the drum head vibration are more real.
And when broadcasting the third movement of Symphony No. 7 of Vaughan Williams published by Naxos , the explosion of the concerto by the organ and the symphony orchestra caused many weaker systems to be ashamed. The power is weak or chaotic. However, QUAD 909MONO has withstood the test. In the strong and oppressive sound pressure, 909MONO still expresses the sound of various musical instruments clearly and thickly, the low frequency and dynamics are always intact , and the shape of the sound field is open and stable. This is a beautiful recording that many people will ignore. It may be because the track is more biased, or it may be that Naxos' low price makes some people look down, but I think that people of insight should not miss it. Listening to the production of a few big scenes, there is no need to say more, enough to verify the benefits of 909MONO's high power and low distortion-strong and accurate.
So, what effect can you achieve with 909MONO to listen to vocals, string and other pieces? Here comes Chen Jieli's fifth album "Your Sweater" in the latest album " One Meter Eight Two Five". The opening guitar solo position is a little within 1 meter behind the right speaker. The details of the strings, the strings, etc. are reproduced clearly, and the oboe appears slightly to the left of the middle of the sound field. The small details of luck and playing have not escaped the expression of 909MONO . The details of vocals are more abundant, and the sounds have delicate and soft qualities.
Listening to Du Moi's trio of Mozart, the delicate and melodious violin sound is delicate and smooth, with the appeal of the appealing. This also proves that QUAD 909MONO's delicate and moisturized sound performance has rid of the impression that people generally think that high-power amplifiers have rough sounds. The delicateness of their sounds is not as good as many low-power products.
Weiliang Chen: From vocals and instrumental ensembles to large-scale orchestras, big operas, electronic music, and powerful movie music, jazz, rock, etc., there are three sets of amplifiers more expensive than 909MONO , But there is no one set that can fully outperform 909MONO ! This is indeed thought-provoking. The QUAD brand can count on its reputation for decades and it really makes sense, but it can also be said to be well-known!
Xueming: In fact, it is really not difficult to define the reliability. What I have paid attention to are two points: 1. The stability of long-term operation; 2. The failure rate. The first point is that I can verify that the 909MONO has been used continuously for a week in the audition room of Audiovisual Frontline. It has been listening for more than 50 hours every day from the start-up to the end-off, and this machine has no trouble. And its sound will enter a stable state soon after starting up. No matter how much the volume is turned up, listening to any burst of music, 909MONO will not change color, the sound will remain constant for a long time. I can be sure of the stability of this long-time work, and the failure rate can be known from the agent ’s mouth. It has been reported that 909MONO has never sold a failure since entering the Guangzhou market. From this data Or, it can be explained on the side that the failure rate of QUAD 909MONO is extremely low.
Delightful and cost-effective
Xue Ming: From the consumer's mentality analysis, of course, I hope that the equipment purchased should not only have good performance, but also have a "flat" price. However, judging from the market development in recent years, the performance of a considerable part of audio equipment has not kept up with the increase in the price, and it has invisibly made people feel that they have to pay a high price to get beautiful sound. But when I look back at QUAD 's products, I was pleasantly surprised to find that QUAD seems to be taking a flat, beautiful, and positive route. While the performance and sound are improved, the price does not change much, so that his products have a very high cost performance. .
Chen Weiliang: Mr. Pteer Walker is old , but QUAD 's audio products still stand up in the field of stereo and continue to carry forward. This is the result of the support and maintenance of their many outstanding audio products!
Especially recent masterpieces: ESL - 989 , ESL - 988 electrostatic speakers, QUAD QC - 24 preamp and QUAD â…¡ 40 , QUAD â…¡ class and QUAD 909MONO Block high-power mono amplifier, etc., replay real and natural Pure music brings joyful and peaceful atmosphere and feeling to people who love peace! 
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