To help you pick a digital amplifier model, I will describe the expression "signal-to-noise ratio" which is commonly used in order to express the performance of audio amps.
As soon as you have chosen a number of amplifiers, it's time to investigate a few of the specs in more detail in order to help you narrow down your search to one model. One important criterion of power amplifiers is the signal-to-noise ratio. To put it simply, the signal-to-noise ratio explains how much hum or hiss the amplifier is going to add to the audio signal. This ratio is generally described in decibel or "db" for short.
Evaluating the noise level of different amps may be done fairly easily. Just get together a number of models that you wish to evaluate and short circuit the inputs. Afterward set the amplifier gain to maximum and verify the level of hiss by listening to the loudspeaker. You are going to hear some amount of hissing and/or hum coming from the speaker. This hiss is generated by the amplifier itself. After that compare several amplifiers according to the following rule: the lower the amount of static, the higher the noise performance of the amplifier. On the other hand, bear in mind that you have to set all amplifiers to amplify by the same amount to compare several amplifiers.
If you favor an amp with a small level of hissing, you can look at the signal-to-noise ratio number of the specification sheet. A lot of manufacturers are going to display this figure. amps with a high signal-to-noise ratio are going to output a small amount of noise. There are several reasons why power amps will add some form of hiss or other unwanted signal. Transistors and resistors that are part of each modern amplifier by nature produce noise. The overall noise is dependent on how much noise each component generates. Nonetheless, the location of those elements is also significant. Components that are part of the amplifier input stage will usually contribute most of the noise.
A lot of today's power amps incorporate a power switching stage that switches at a frequency around 500 kHz. This switching noise can result in some amount of speaker distortion but is typically not included in the the signal-to-noise ratio which merely considers noise in the range of 20 Hz and 20 kHz.
The most widespread method for measuring the signal-to-noise ratio is to set the amp to a gain that enables the maximum output swing. Subsequently a test tone is fed to the amplifier. The frequency of this tone is generally 1 kHz. The amplitude of this signal is 60 dB underneath the full scale signal. After that, only the hiss between 20 Hz and 20 kHz is considered. The noise at other frequencies is eliminated via a filter. After that the amount of the noise energy in relation to the full-scale output wattage is calculated and expressed in db.
Frequently you are going to find the term "dBA" or "a-weighted" in your amp spec sheet. A weighting is a method of expressing the noise floor in a more subjective way. This method was developed with the knowledge that human hearing perceives noise at different frequencies differently. Human hearing is most sensitive to signals around 1 kHz. Then again, signals under 50 Hz and higher than 13 kHz are barely noticed. An A-weighted signal-to-noise ratio weighs the noise floor according to the human hearing and is typically larger than the unweighted signal-to-noise ratio.
As soon as you have chosen a number of amplifiers, it's time to investigate a few of the specs in more detail in order to help you narrow down your search to one model. One important criterion of power amplifiers is the signal-to-noise ratio. To put it simply, the signal-to-noise ratio explains how much hum or hiss the amplifier is going to add to the audio signal. This ratio is generally described in decibel or "db" for short.
Evaluating the noise level of different amps may be done fairly easily. Just get together a number of models that you wish to evaluate and short circuit the inputs. Afterward set the amplifier gain to maximum and verify the level of hiss by listening to the loudspeaker. You are going to hear some amount of hissing and/or hum coming from the speaker. This hiss is generated by the amplifier itself. After that compare several amplifiers according to the following rule: the lower the amount of static, the higher the noise performance of the amplifier. On the other hand, bear in mind that you have to set all amplifiers to amplify by the same amount to compare several amplifiers.
If you favor an amp with a small level of hissing, you can look at the signal-to-noise ratio number of the specification sheet. A lot of manufacturers are going to display this figure. amps with a high signal-to-noise ratio are going to output a small amount of noise. There are several reasons why power amps will add some form of hiss or other unwanted signal. Transistors and resistors that are part of each modern amplifier by nature produce noise. The overall noise is dependent on how much noise each component generates. Nonetheless, the location of those elements is also significant. Components that are part of the amplifier input stage will usually contribute most of the noise.
A lot of today's power amps incorporate a power switching stage that switches at a frequency around 500 kHz. This switching noise can result in some amount of speaker distortion but is typically not included in the the signal-to-noise ratio which merely considers noise in the range of 20 Hz and 20 kHz.
The most widespread method for measuring the signal-to-noise ratio is to set the amp to a gain that enables the maximum output swing. Subsequently a test tone is fed to the amplifier. The frequency of this tone is generally 1 kHz. The amplitude of this signal is 60 dB underneath the full scale signal. After that, only the hiss between 20 Hz and 20 kHz is considered. The noise at other frequencies is eliminated via a filter. After that the amount of the noise energy in relation to the full-scale output wattage is calculated and expressed in db.
Frequently you are going to find the term "dBA" or "a-weighted" in your amp spec sheet. A weighting is a method of expressing the noise floor in a more subjective way. This method was developed with the knowledge that human hearing perceives noise at different frequencies differently. Human hearing is most sensitive to signals around 1 kHz. Then again, signals under 50 Hz and higher than 13 kHz are barely noticed. An A-weighted signal-to-noise ratio weighs the noise floor according to the human hearing and is typically larger than the unweighted signal-to-noise ratio.
About the Author:
You can get further information about audio amplifiers as well as t amp models from Amphony's website.
0 comments:
Post a Comment