To help you pick an audio amp, I am going to clarify the expression "signal-to-noise ratio" which is regularly utilized to describe the performance of audio amps. Whilst trying to find an amp, you firstly are going to check the cost, wattage amongst other basic criteria. Nonetheless, after this initial choice, you are going to still have numerous products to choose from. Next you are going to concentrate more on a number of of the technical specs, such as signal-to-noise ratio in addition to harmonic distortion. Each amp is going to generate a certain level of hiss and hum. The signal-to-noise ratio is going to help calculate the level of hiss created by the amplifier.
Comparing the noise level of different amps can be accomplished fairly easily. Just gather a few versions which you want to compare and short circuit the inputs. Next put the amp gain to maximum and check the amount of static by listening to the speaker. Usually you are going to hear 2 components. The first is hissing. In addition, you will frequently hear a hum at 50 or 60 Hz. Both of these are components which are created by the amp itself. After that compare several amps according to the following rule: the lower the level of static, the higher the noise performance of the amplifier. Though, bear in mind that you should set all amplifiers to amplify by the same level in order to evaluate several amps.
You can make a simple assessment of the amp hiss by short circuiting the amplifier input, setting the volume to maximum and listening to a loudspeaker connected to the amplifier. Generally you will hear two components. The first is hissing. In addition, you will often hear a hum at 50 or 60 Hz. Both of these are components which are produced by the amp itself. After that compare several amplifiers according to the following rule: the smaller the level of static, the better the noise performance of the amp. However, bear in mind that you should put all amplifiers to amplify by the same level to compare different amplifiers.
To help you evaluate the noise performance, amplifier suppliers show the signal-to-noise ratio in their amp spec sheets. Simply put, the higher the signal-to-noise ratio, the lower the amount of noise the amp produces. There are several reasons why power amps will add some form of noise or other unwanted signal. Transistors and resistors which are part of each modern amplifier by nature create noise. Typically the components that are situated at the input stage of an amplifier are going to contribute most to the overall noise. Thus suppliers generally are going to select low-noise elements while developing the amp input stage.
A lot of of latest amps are based on a digital switching topology. They are referred to as "class-D" or "class-T" amplifiers. Switching amplifiers incorporate a power stage which is constantly switched at a frequency of approximately 400 kHz. This switching frequency is also noise which is part of the amplified signal. Yet, latest amplifier specs generally only consider the noise between 20 Hz and 20 kHz. Producers measure the signal-to-noise ratio by setting the amplifier such that the full output swing can be realized and by feeding a test signal to the amplifier which is typically 60 dB underneath the full scale of the amp. Subsequently the noise-floor energy is calculated in the frequency range between 20 Hz and 20 kHz and compared with the full scale signal energy.
Frequently you are going to discover the term "dBA" or "a-weighted" in your amp parameter sheet. A weighting is a method of showing the noise floor in a more subjective manner. In other words, this technique tries to state how the noise is perceived by a human being. Human hearing is most sensitive to signals around 1 kHz whereas signals under 50 Hz and above 14 kHz are hardly heard. As a result an A-weighting filter will amplify the noise floor for frequencies that are easily heard and suppress the noise floor at frequencies that are barely noticed. A lot of amplifiers will show a higher A-weighted signal-to-noise ratio than the un-weighted ratio.
Comparing the noise level of different amps can be accomplished fairly easily. Just gather a few versions which you want to compare and short circuit the inputs. Next put the amp gain to maximum and check the amount of static by listening to the speaker. Usually you are going to hear 2 components. The first is hissing. In addition, you will frequently hear a hum at 50 or 60 Hz. Both of these are components which are created by the amp itself. After that compare several amps according to the following rule: the lower the level of static, the higher the noise performance of the amplifier. Though, bear in mind that you should set all amplifiers to amplify by the same level in order to evaluate several amps.
You can make a simple assessment of the amp hiss by short circuiting the amplifier input, setting the volume to maximum and listening to a loudspeaker connected to the amplifier. Generally you will hear two components. The first is hissing. In addition, you will often hear a hum at 50 or 60 Hz. Both of these are components which are produced by the amp itself. After that compare several amplifiers according to the following rule: the smaller the level of static, the better the noise performance of the amp. However, bear in mind that you should put all amplifiers to amplify by the same level to compare different amplifiers.
To help you evaluate the noise performance, amplifier suppliers show the signal-to-noise ratio in their amp spec sheets. Simply put, the higher the signal-to-noise ratio, the lower the amount of noise the amp produces. There are several reasons why power amps will add some form of noise or other unwanted signal. Transistors and resistors which are part of each modern amplifier by nature create noise. Typically the components that are situated at the input stage of an amplifier are going to contribute most to the overall noise. Thus suppliers generally are going to select low-noise elements while developing the amp input stage.
A lot of of latest amps are based on a digital switching topology. They are referred to as "class-D" or "class-T" amplifiers. Switching amplifiers incorporate a power stage which is constantly switched at a frequency of approximately 400 kHz. This switching frequency is also noise which is part of the amplified signal. Yet, latest amplifier specs generally only consider the noise between 20 Hz and 20 kHz. Producers measure the signal-to-noise ratio by setting the amplifier such that the full output swing can be realized and by feeding a test signal to the amplifier which is typically 60 dB underneath the full scale of the amp. Subsequently the noise-floor energy is calculated in the frequency range between 20 Hz and 20 kHz and compared with the full scale signal energy.
Frequently you are going to discover the term "dBA" or "a-weighted" in your amp parameter sheet. A weighting is a method of showing the noise floor in a more subjective manner. In other words, this technique tries to state how the noise is perceived by a human being. Human hearing is most sensitive to signals around 1 kHz whereas signals under 50 Hz and above 14 kHz are hardly heard. As a result an A-weighting filter will amplify the noise floor for frequencies that are easily heard and suppress the noise floor at frequencies that are barely noticed. A lot of amplifiers will show a higher A-weighted signal-to-noise ratio than the un-weighted ratio.
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You can find detailed infos regarding power amps at http://www.amphony.com. On top of that, have a look at http://speaker-s.com/hifi-speakers/.