If you are about to acquire a new stereo amplifier, you may be concerned about how efficiently your amp works. I will show you exactly what the term “power efficiency” means plus why you need to take a closer look at this number in your selection of a brand new amplifier.
A fairly large amount of power is radiated as heat should you get a low-efficiency amp. This can contribute to several issues: Amps that have small power efficiency are going to waste some energy. It is smart to bear in mind the added energy expense while choosing between a high- and low-efficiency product. The squandered energy is radiated by the amp as heat. Amplifiers that have lower efficiency typically have various heat sinks to help dissipate the wasted energy. These heat sinks use up a good amount of space and make the amplifier large and heavy. Further, they raise the price of the amp. To help radiate heat, low-power-efficiency amplifiers need to have adequate air movement. As a result they can not be placed in areas with no circulation. Also, they cannot be installed inside water-resistant enclosures.
Amplifiers that have low efficiency require a bigger power source to create the identical amount of audio power as high-efficiency products. Further, because of the large level of heat, there will be significantly greater thermal stress on the electrical elements and also interior materials which may cause dependability complications. In contrast, high-efficiency amplifiers can be made small and light.
While buying an amplifier, you’ll find the efficiency in the data sheet. This figure is frequently shown as a percentage. Class-A amplifiers are amongst the least efficient and provide a efficiency of around 25% only. On the other hand, switching amplifiers, also referred to as “Class-D” amplifiers provide efficiencies of up to 98%. Acquiring an amplifier which has an efficiency of 90% as an example shows that 10% of the energy that is used is squandered while 90% will be audio power.
Then again, there are a few things to note about power efficiency. First of all, this figure will depend on on the level of energy that the amplifier is providing. Amplifiers have greater efficiency while delivering larger output power than when operating at low power mainly because of the fixed power that they consume irrespective of the output power. The efficiency value in the amp data sheet is usually provided for the greatest amplifier output power.
To determine the power efficiency, the audio energy that is used by a power resistor which is connected to the amplifier is divided by the overall energy the amp consumes while being fed a constant sine wave signal. Since the efficiency is dependent upon the audio power, usually the output power is swept and an efficiency graph generated which can display the amplifier efficiency for each level of output power.
When choosing a sound amp you will need to weigh efficiency versus fidelity given that low-efficiency analog amps frequently deliver the maximum audio fidelity whilst digital models will have greater distortion. However, digital amplifiers have come a long way and are offering better music fidelity than in the past. Class-T amplifiers come close to the music fidelity of analog amps. Due to this fact picking a switching amplifier with good audio fidelity is now possible.