To help you choose an audio amp, I am going to describe the expression "signal-to-noise ratio" which is commonly used to describe the performance of audio amplifiers.
You can do a straightforward comparison of the amplifier hiss by short circuiting the amp input, setting the gain to maximum and listening to a loudspeaker attached to the amp. You will hear some amount of hissing and/or hum coming from the speaker. This noise is produced by the amp itself. Be certain that the volume of the amps is set to the same amount. Otherwise you will not be able to objectively evaluate the amount of noise between different amplifiers. The general rule is: the smaller the amount of hiss that you hear the higher the noise performance.
If you prefer an amplifier with a small level of hissing, you can look at the signal-to-noise ratio number of the specification sheet. The majority of suppliers will display this number. Amps with a high signal-to-noise ratio will output a small level of hiss. One of the reasons why amps produce noise is the fact that they use components like transistors as well as resistors that by nature generate noise. The overall noise depends on how much noise every element creates. However, the position of these elements is also significant. Components that are part of the amplifier input stage are going to in general contribute most of the noise.
Most recent power amplifiers incorporate a wattage switching stage which switches at a frequency around 500 kHz. This switching noise can result in a certain amount of loudspeaker distortion yet is usually not included in the the signal-to-noise ratio which only considers noise in the range of 20 Hz and 20 kHz.
Manufacturers measure the signal-to-noise ratio by setting the amp such that the full output swing may be achieved and by inputting a test signal to the amplifier that is usually 60 dB below the full scale of the amp. Subsequently the noise-floor energy is measured in the frequency range between 20 Hz and 20 kHz and compared with the full scale signal energy.
Frequently the signal-to-noise ratio is shown in a more subjective method as "dbA" or "A weighted". This technique was designed with the knowledge that human hearing perceives noise at different frequencies differently. Human hearing is most responsive to signals around 1 kHz. Then again, signals under 50 Hz and above 13 kHz are hardly noticed. An A-weighted signal-to-noise ratio weighs the noise floor in accordance to the human hearing and is usually larger than the unweighted signal-to-noise ratio.
You can do a straightforward comparison of the amplifier hiss by short circuiting the amp input, setting the gain to maximum and listening to a loudspeaker attached to the amp. You will hear some amount of hissing and/or hum coming from the speaker. This noise is produced by the amp itself. Be certain that the volume of the amps is set to the same amount. Otherwise you will not be able to objectively evaluate the amount of noise between different amplifiers. The general rule is: the smaller the amount of hiss that you hear the higher the noise performance.
If you prefer an amplifier with a small level of hissing, you can look at the signal-to-noise ratio number of the specification sheet. The majority of suppliers will display this number. Amps with a high signal-to-noise ratio will output a small level of hiss. One of the reasons why amps produce noise is the fact that they use components like transistors as well as resistors that by nature generate noise. The overall noise depends on how much noise every element creates. However, the position of these elements is also significant. Components that are part of the amplifier input stage are going to in general contribute most of the noise.
Most recent power amplifiers incorporate a wattage switching stage which switches at a frequency around 500 kHz. This switching noise can result in a certain amount of loudspeaker distortion yet is usually not included in the the signal-to-noise ratio which only considers noise in the range of 20 Hz and 20 kHz.
Manufacturers measure the signal-to-noise ratio by setting the amp such that the full output swing may be achieved and by inputting a test signal to the amplifier that is usually 60 dB below the full scale of the amp. Subsequently the noise-floor energy is measured in the frequency range between 20 Hz and 20 kHz and compared with the full scale signal energy.
Frequently the signal-to-noise ratio is shown in a more subjective method as "dbA" or "A weighted". This technique was designed with the knowledge that human hearing perceives noise at different frequencies differently. Human hearing is most responsive to signals around 1 kHz. Then again, signals under 50 Hz and above 13 kHz are hardly noticed. An A-weighted signal-to-noise ratio weighs the noise floor in accordance to the human hearing and is usually larger than the unweighted signal-to-noise ratio.
About the Author:
Visit this informative post to study detailed information on the subject of d class amplifiers. Additionally, surf over to http://cranfieldaudio.com/.
No comments:
Post a Comment