First, how should the noise floor noise be measured? Anyone who has used a digital multimeter knows that if the watch is dialed to the millivolt file and the test pen is left unconnected, the number of the watch has begun to jump. The number of beating is as little as 3, 5 millivolts and as many as tens of millivolts. Is the accuracy of this multimeter so low that it can't measure millivolt-level parameters? Not also. As long as the two test leads are docked together, the head immediately returns to zero stability. So how did the number that just jumped come? Because there are stray electromagnetic interference signals scattered around the space, and the internal resistance of the multimeter is relatively large, the interference signal can be very sensitively accepted. Once the test leads are docked, the interfering electromagnetic signals are shorted by the test leads. The multimeter shows a stable zero return, indicating how much the minimum signal range it can measure. On the other hand, if you look at the amplifier, if you open the input terminal and turn the volume to the maximum, then the noise you hear, like the multimeter just now, has quite a lot of space electromagnetic interference noise. Then you find a signal plug with no wiring, and connect the two ends of the plug to a short circuit. What do you hear? There may be no sound or very little noise. This is the noise floor of the amplifier. Then, you may also ask, isn't it possible to turn the volume to a minimum? Yes, sometimes it may be like this, for example, the volume potentiometer is at the front of the circuit. However, there are also circuit volume potentiometers that are not at the forefront. There may be other circuit components or wiring in front of them. You turn it off to a minimum, and the noise reflected is only the noise of the circuit after the potentiometer. Therefore, the correct measurement method should be short-circuiting the input terminal, and the noise at the maximum volume is the noise floor of the amplifier.
Second, maybe you will ask again, can you reduce the input impedance of the amplifier to zero, just like the multimeter's test pen docking, the interference signal is not there? Yes! Can you think about it, isn't there any signal transmitted from the front? Therefore, the input impedance of the rear amplifier can not be absent, lower, the received spatial interference noise is smaller. Therefore, the use of volume potentiometers for 20k is a practice for many people. Of course, the input impedance of the amplifier circuit behind the potentiometer is a little higher, which is good for capturing weak signals.
Third, however, after the amplifier is connected to the CD player, even if the volume is turned to the maximum, the noise will be small? Because the internal resistance of the CD signal output is very low, the spatial electromagnetic stray signal induced on the signal line is short-circuited by the output circuit inside the CD player. If the noise you hear is shorter than the amplifier input, then the big part is the noise floor of the CD player.
Fourth, please note that the noise floor of the CD player is not as simple as the above. Because most CD players, especially imported low-end CD players, it has a mute circuit at the front of the signal output terminal. When the CD player stops playing, when the song is changed, the song pauses for a long time. When the memory jumps, the mute circuit starts to work. At this time, the noise heard is small, which is not equal to the noise floor of the CD player. The same is true when the CD headphone jack is listening to headphones. In addition to the above several times, there are two aspects of the noise heard when the CD player plays the sound. One is the noise level determined by the CD machine's chip grade level and the circuit design level. This is the noise floor of the CD player; It is the noise on the recording, this is no way.
Fifth, the sensitivity of the earphone machine is high, of course, you can hear more noise. But how much noise is heard by this amplifier? According to the above, you can judge for yourself. First, how should the noise floor noise be measured? Anyone who has used a digital multimeter knows that if the watch is dialed to the millivolt file and the test pen is left unconnected, the number of the watch has begun to jump. The number of beating is as little as 3, 5 millivolts and as many as tens of millivolts. Is the accuracy of this multimeter so low that it can't measure millivolt-level parameters? Not also. As long as the two test leads are docked together, the head immediately returns to zero stability. So how did the number that just jumped come? Because there are stray electromagnetic interference signals scattered around the space, and the internal resistance of the multimeter is relatively large, the interference signal can be very sensitively accepted. Once the test leads are docked, the interfering electromagnetic signals are shorted by the test leads. The multimeter shows a stable zero return, indicating how much the minimum signal range it can measure. On the other hand, if you look at the amplifier, if you open the input terminal and turn the volume to the maximum, then the noise you hear, like the multimeter just now, has quite a lot of space electromagnetic interference noise. Then you find a signal plug with no wiring, and connect the two ends of the plug to a short circuit. What do you hear? There may be no sound or very little noise. This is the noise floor of the amplifier. Then, you may also ask, isn't it possible to turn the volume to a minimum? Yes, sometimes it may be like this, for example, the volume potentiometer is at the front of the circuit. However, there are also circuit volume potentiometers that are not at the forefront. There may be other circuit components or wiring in front of them. You turn it off to a minimum, and the noise reflected is only the noise of the circuit after the potentiometer. Therefore, the correct measurement method should be short-circuiting the input terminal, and the noise at the maximum volume is the noise floor of the amplifier.
Second, maybe you will ask again, can you reduce the input impedance of the amplifier to zero, just like the multimeter's test pen docking, the interference signal is not there? Yes! Can you think about it, isn't there any signal transmitted from the front? Therefore, the input impedance of the rear amplifier can not be absent, lower, the received spatial interference noise is smaller. Therefore, the use of volume potentiometers for 20k is a practice for many people. Of course, the input impedance of the amplifier circuit behind the potentiometer is a little higher, which is good for capturing weak signals.
Third, however, after the amplifier is connected to the CD player, even if the volume is turned to the maximum, the noise will be small? Because the internal resistance of the CD signal output is very low, the spatial electromagnetic stray signal induced on the signal line is short-circuited by the output circuit inside the CD player. If the noise you hear is shorter than the amplifier input, then the big part is the noise floor of the CD player.
Fourth, please note that the noise floor of the CD player is not as simple as the above. Because most CD players, especially imported low-end CD players, it has a mute circuit at the front of the signal output terminal. When the CD player stops playing, when the song is changed, the song pauses for a long time. When the memory jumps, the mute circuit starts to work. At this time, the noise heard is small, which is not equal to the noise floor of the CD player. The same is true when the CD headphone jack is listening to headphones. In addition to the above several times, there are two aspects of the noise heard when the CD player plays the sound. One is the noise level determined by the CD machine's chip grade level and the circuit design level. This is the noise floor of the CD player; It is the noise on the recording, this is no way.
Fifth, the sensitivity of the earphone machine is high, of course, you can hear more noise. But how much noise is heard by this amplifier? According to the above, you can judge for yourself. First, how should the noise floor noise be measured? Anyone who has used a digital multimeter knows that if the watch is dialed to the millivolt file and the test pen is left unconnected, the number of the watch has begun to jump. The number of beating is as little as 3, 5 millivolts and as many as tens of millivolts. Is the accuracy of this multimeter so low that it can't measure millivolt-level parameters? Not also. As long as the two test leads are docked together, the head immediately returns to zero stability. So how did the number that just jumped come? Because there are stray electromagnetic interference signals scattered around the space, and the internal resistance of the multimeter is relatively large, the interference signal can be very sensitively accepted. Once the test leads are docked, the interfering electromagnetic signals are shorted by the test leads. The multimeter shows a stable zero return, indicating how much the minimum signal range it can measure. On the other hand, if you look at the amplifier, if you open the input terminal and turn the volume to the maximum, then the noise you hear, like the multimeter just now, has quite a lot of space electromagnetic interference noise. Then you find a signal plug with no wiring, and connect the two ends of the plug to a short circuit. What do you hear? There may be no sound or very little noise. This is the noise floor of the amplifier. Then, you may also ask, isn't it possible to turn the volume to a minimum? Yes, sometimes it may be like this, for example, the volume potentiometer is at the front of the circuit. However, there are also circuit volume potentiometers that are not at the forefront. There may be other circuit components or wiring in front of them. You turn it off to a minimum, and the noise reflected is only the noise of the circuit after the potentiometer. Therefore, the correct measurement method should be short-circuiting the input terminal, and the noise at the maximum volume is the noise floor of the amplifier.
Second, maybe you will ask again, can you reduce the input impedance of the amplifier to zero, just like the multimeter's test pen docking, the interference signal is not there? Yes! Can you think about it, isn't there any signal transmitted from the front? Therefore, the input impedance of the rear amplifier can not be absent, lower, the received spatial interference noise is smaller. Therefore, the use of volume potentiometers for 20k is a practice for many people. Of course, the input impedance of the amplifier circuit behind the potentiometer is a little higher, which is good for capturing weak signals.
Third, however, after the amplifier is connected to the CD player, even if the volume is turned to the maximum, the noise will be small? Because the internal resistance of the CD signal output is very low, the spatial electromagnetic stray signal induced on the signal line is short-circuited by the output circuit inside the CD player. If the noise you hear is shorter than the amplifier input, then the big part is the noise floor of the CD player.
Fourth, please note that the noise floor of the CD player is not as simple as the above. Because most CD players, especially imported low-end CD players, it has a mute circuit at the front of the signal output terminal. When the CD player stops playing, when the song is changed, the song pauses for a long time. When the memory jumps, the mute circuit starts to work. At this time, the noise heard is small, which is not equal to the noise floor of the CD player. The same is true when the CD headphone jack is listening to headphones. In addition to the above several times, there are two aspects of the noise heard when the CD player plays the sound. One is the noise level determined by the CD machine's chip grade level and the circuit design level. This is the noise floor of the CD player; It is the noise on the recording, this is no way.
Fifth, the sensitivity of the earphone machine is high, of course, you can hear more noise. But how much noise is heard by this amplifier? According to the above, you can judge for yourself.
Second, maybe you will ask again, can you reduce the input impedance of the amplifier to zero, just like the multimeter's test pen docking, the interference signal is not there? Yes! Can you think about it, isn't there any signal transmitted from the front? Therefore, the input impedance of the rear amplifier can not be absent, lower, the received spatial interference noise is smaller. Therefore, the use of volume potentiometers for 20k is a practice for many people. Of course, the input impedance of the amplifier circuit behind the potentiometer is a little higher, which is good for capturing weak signals.
Third, however, after the amplifier is connected to the CD player, even if the volume is turned to the maximum, the noise will be small? Because the internal resistance of the CD signal output is very low, the spatial electromagnetic stray signal induced on the signal line is short-circuited by the output circuit inside the CD player. If the noise you hear is shorter than the amplifier input, then the big part is the noise floor of the CD player.
Fourth, please note that the noise floor of the CD player is not as simple as the above. Because most CD players, especially imported low-end CD players, it has a mute circuit at the front of the signal output terminal. When the CD player stops playing, when the song is changed, the song pauses for a long time. When the memory jumps, the mute circuit starts to work. At this time, the noise heard is small, which is not equal to the noise floor of the CD player. The same is true when the CD headphone jack is listening to headphones. In addition to the above several times, there are two aspects of the noise heard when the CD player plays the sound. One is the noise level determined by the CD machine's chip grade level and the circuit design level. This is the noise floor of the CD player; It is the noise on the recording, this is no way.
Fifth, the sensitivity of the earphone machine is high, of course, you can hear more noise. But how much noise is heard by this amplifier? According to the above, you can judge for yourself. First, how should the noise floor noise be measured? Anyone who has used a digital multimeter knows that if the watch is dialed to the millivolt file and the test pen is left unconnected, the number of the watch has begun to jump. The number of beating is as little as 3, 5 millivolts and as many as tens of millivolts. Is the accuracy of this multimeter so low that it can't measure millivolt-level parameters? Not also. As long as the two test leads are docked together, the head immediately returns to zero stability. So how did the number that just jumped come? Because there are stray electromagnetic interference signals scattered around the space, and the internal resistance of the multimeter is relatively large, the interference signal can be very sensitively accepted. Once the test leads are docked, the interfering electromagnetic signals are shorted by the test leads. The multimeter shows a stable zero return, indicating how much the minimum signal range it can measure. On the other hand, if you look at the amplifier, if you open the input terminal and turn the volume to the maximum, then the noise you hear, like the multimeter just now, has quite a lot of space electromagnetic interference noise. Then you find a signal plug with no wiring, and connect the two ends of the plug to a short circuit. What do you hear? There may be no sound or very little noise. This is the noise floor of the amplifier. Then, you may also ask, isn't it possible to turn the volume to a minimum? Yes, sometimes it may be like this, for example, the volume potentiometer is at the front of the circuit. However, there are also circuit volume potentiometers that are not at the forefront. There may be other circuit components or wiring in front of them. You turn it off to a minimum, and the noise reflected is only the noise of the circuit after the potentiometer. Therefore, the correct measurement method should be short-circuiting the input terminal, and the noise at the maximum volume is the noise floor of the amplifier.
Second, maybe you will ask again, can you reduce the input impedance of the amplifier to zero, just like the multimeter's test pen docking, the interference signal is not there? Yes! Can you think about it, isn't there any signal transmitted from the front? Therefore, the input impedance of the rear amplifier can not be absent, lower, the received spatial interference noise is smaller. Therefore, the use of volume potentiometers for 20k is a practice for many people. Of course, the input impedance of the amplifier circuit behind the potentiometer is a little higher, which is good for capturing weak signals.
Third, however, after the amplifier is connected to the CD player, even if the volume is turned to the maximum, the noise will be small? Because the internal resistance of the CD signal output is very low, the spatial electromagnetic stray signal induced on the signal line is short-circuited by the output circuit inside the CD player. If the noise you hear is shorter than the amplifier input, then the big part is the noise floor of the CD player.
Fourth, please note that the noise floor of the CD player is not as simple as the above. Because most CD players, especially imported low-end CD players, it has a mute circuit at the front of the signal output terminal. When the CD player stops playing, when the song is changed, the song pauses for a long time. When the memory jumps, the mute circuit starts to work. At this time, the noise heard is small, which is not equal to the noise floor of the CD player. The same is true when the CD headphone jack is listening to headphones. In addition to the above several times, there are two aspects of the noise heard when the CD player plays the sound. One is the noise level determined by the CD machine's chip grade level and the circuit design level. This is the noise floor of the CD player; It is the noise on the recording, this is no way.
Fifth, the sensitivity of the earphone machine is high, of course, you can hear more noise. But how much noise is heard by this amplifier? According to the above, you can judge for yourself. First, how should the noise floor noise be measured? Anyone who has used a digital multimeter knows that if the watch is dialed to the millivolt file and the test pen is left unconnected, the number of the watch has begun to jump. The number of beating is as little as 3, 5 millivolts and as many as tens of millivolts. Is the accuracy of this multimeter so low that it can't measure millivolt-level parameters? Not also. As long as the two test leads are docked together, the head immediately returns to zero stability. So how did the number that just jumped come? Because there are stray electromagnetic interference signals scattered around the space, and the internal resistance of the multimeter is relatively large, the interference signal can be very sensitively accepted. Once the test leads are docked, the interfering electromagnetic signals are shorted by the test leads. The multimeter shows a stable zero return, indicating how much the minimum signal range it can measure. On the other hand, if you look at the amplifier, if you open the input terminal and turn the volume to the maximum, then the noise you hear, like the multimeter just now, has quite a lot of space electromagnetic interference noise. Then you find a signal plug with no wiring, and connect the two ends of the plug to a short circuit. What do you hear? There may be no sound or very little noise. This is the noise floor of the amplifier. Then, you may also ask, isn't it possible to turn the volume to a minimum? Yes, sometimes it may be like this, for example, the volume potentiometer is at the front of the circuit. However, there are also circuit volume potentiometers that are not at the forefront. There may be other circuit components or wiring in front of them. You turn it off to a minimum, and the noise reflected is only the noise of the circuit after the potentiometer. Therefore, the correct measurement method should be short-circuiting the input terminal, and the noise at the maximum volume is the noise floor of the amplifier.
Second, maybe you will ask again, can you reduce the input impedance of the amplifier to zero, just like the multimeter's test pen docking, the interference signal is not there? Yes! Can you think about it, isn't there any signal transmitted from the front? Therefore, the input impedance of the rear amplifier can not be absent, lower, the received spatial interference noise is smaller. Therefore, the use of volume potentiometers for 20k is a practice for many people. Of course, the input impedance of the amplifier circuit behind the potentiometer is a little higher, which is good for capturing weak signals.
Third, however, after the amplifier is connected to the CD player, even if the volume is turned to the maximum, the noise will be small? Because the internal resistance of the CD signal output is very low, the spatial electromagnetic stray signal induced on the signal line is short-circuited by the output circuit inside the CD player. If the noise you hear is shorter than the amplifier input, then the big part is the noise floor of the CD player.
Fourth, please note that the noise floor of the CD player is not as simple as the above. Because most CD players, especially imported low-end CD players, it has a mute circuit at the front of the signal output terminal. When the CD player stops playing, when the song is changed, the song pauses for a long time. When the memory jumps, the mute circuit starts to work. At this time, the noise heard is small, which is not equal to the noise floor of the CD player. The same is true when the CD headphone jack is listening to headphones. In addition to the above several times, there are two aspects of the noise heard when the CD player plays the sound. One is the noise level determined by the CD machine's chip grade level and the circuit design level. This is the noise floor of the CD player; It is the noise on the recording, this is no way.
Fifth, the sensitivity of the earphone machine is high, of course, you can hear more noise. But how much noise is heard by this amplifier? According to the above, you can judge for yourself.
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