Picking a good audio amplifier for your speakers is not a trivial task. You want to ensure that your amp matches your speakers. I will explain some basic amplifier terms and give some pointers to help you pick the best amplifier.
There is a flood of different audio amplifiers available which all differ in their specifications, shape and size. However, you don't need to be an expert to pick the best model. By following some basic rules you won't regret your buying decision.
The most apparent parameter is the size of the amplifier. There are models that are as big as half your living room while some of the newest mini amplifier models are as small as a bar of soap. A large number of amps are the size of a standard rack. This allows your amp to be stacked on top of your other audio devices.
There are some core amplifier technologies available. One technology is called "solid-state". Solid-state amps now account for the majority of audio amplifiers. In the past, tube amplifiers have been popular. Even today tube amplifiers are still available. Tube amplifiers, however, have a fairly high amount of harmonic distortion. Harmonic distortion refers to how much the audio signal is degraded while being amplified. This term is often used while comparing the audio quality of amplifiers.
An audio distortion of up to 10% is typical for tube amps while solid-state amps have lower audio distortion depending on the particular technology. In the past, mostly "Class-A" and "Class-AB" amps were available which are also known as "analog amplifiers". While amplifiers using these technologies typically have low audio distortion, power efficiency is only 10% to 30%. Power efficiency refers to how much of the electrical power is actually used to amplify the signal. The remaining portion is wasted as heat. An amplifier with low power efficiency will radiate most of its power as heat.
"Class-D" amplifiers, however, which are also called "digital amplifiers" have a power efficiency of at least 80% and are smaller and have a smaller power supply than comparable analog amplifiers. The downside is that many digital amplifiers have higher audio distortion than analog amplifiers although some of the latest models employ a feedback mechanism to reduce distortion to levels of 0.05% and below.
Your amplifier should deliver sufficient power to drive your speakers. The amount of power will depend on the power handling rating of your speakers. Another factor is the size of your room. There are two values for speaker power handling: peak and average power handling. The peak value shows how much power the speaker can handle for short periods of time. The average value on the other hand describes how much power the speaker can tolerate continuously without damage.
In a small listening environment, you may not need to drive your speakers to their rated value. 20 to 40 Watts of power will probably be plenty. Speakers however differ in their impedance and sensitivity. As a rule of thumb speakers with low impedance offer higher sensitivity. High-sensitivity speakers are easier to drive to high volume than low-sensitivity speakers. Not all amplifiers can drive any speaker impedance. Find out the impedance of your speaker which is given in Ohms. Then look at your amplifier manual to ensure that your amp can drive this impedance.
Lastly, make sure that your amplifier introduces little noise and has a broad enough frequency response. High-quality amplifiers will have a signal-to-noise ratio of at least 100 dB and a frequency response of at least 20 Hz to 20 kHz.
There is a flood of different audio amplifiers available which all differ in their specifications, shape and size. However, you don't need to be an expert to pick the best model. By following some basic rules you won't regret your buying decision.
The most apparent parameter is the size of the amplifier. There are models that are as big as half your living room while some of the newest mini amplifier models are as small as a bar of soap. A large number of amps are the size of a standard rack. This allows your amp to be stacked on top of your other audio devices.
There are some core amplifier technologies available. One technology is called "solid-state". Solid-state amps now account for the majority of audio amplifiers. In the past, tube amplifiers have been popular. Even today tube amplifiers are still available. Tube amplifiers, however, have a fairly high amount of harmonic distortion. Harmonic distortion refers to how much the audio signal is degraded while being amplified. This term is often used while comparing the audio quality of amplifiers.
An audio distortion of up to 10% is typical for tube amps while solid-state amps have lower audio distortion depending on the particular technology. In the past, mostly "Class-A" and "Class-AB" amps were available which are also known as "analog amplifiers". While amplifiers using these technologies typically have low audio distortion, power efficiency is only 10% to 30%. Power efficiency refers to how much of the electrical power is actually used to amplify the signal. The remaining portion is wasted as heat. An amplifier with low power efficiency will radiate most of its power as heat.
"Class-D" amplifiers, however, which are also called "digital amplifiers" have a power efficiency of at least 80% and are smaller and have a smaller power supply than comparable analog amplifiers. The downside is that many digital amplifiers have higher audio distortion than analog amplifiers although some of the latest models employ a feedback mechanism to reduce distortion to levels of 0.05% and below.
Your amplifier should deliver sufficient power to drive your speakers. The amount of power will depend on the power handling rating of your speakers. Another factor is the size of your room. There are two values for speaker power handling: peak and average power handling. The peak value shows how much power the speaker can handle for short periods of time. The average value on the other hand describes how much power the speaker can tolerate continuously without damage.
In a small listening environment, you may not need to drive your speakers to their rated value. 20 to 40 Watts of power will probably be plenty. Speakers however differ in their impedance and sensitivity. As a rule of thumb speakers with low impedance offer higher sensitivity. High-sensitivity speakers are easier to drive to high volume than low-sensitivity speakers. Not all amplifiers can drive any speaker impedance. Find out the impedance of your speaker which is given in Ohms. Then look at your amplifier manual to ensure that your amp can drive this impedance.
Lastly, make sure that your amplifier introduces little noise and has a broad enough frequency response. High-quality amplifiers will have a signal-to-noise ratio of at least 100 dB and a frequency response of at least 20 Hz to 20 kHz.
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You can get further information regarding audio amplifier technologies at Amphony's website.
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