Do Amplifiers Need Running In?

It is common knowledge that audio components – including cables, speakers, and amplifiers, need a break-in period to ensure they sound their best when you use them. While this thought may sound reasonable, it is easy to not pay as much attention to it because you are not controlling the sound quality and production; you are only listening to the output. With this in mind, you may wonder if it is necessary to break them in when setting up the system.

Yes, it is necessary to allow your amplifier to run in, to guarantee improved performance. This is due to allowing specific components like capacitors to perform at an optimal constant, and ultimately improving the sound quality over time. The time it takes to run can vary between amplifiers, but the general consensus is to allow this process for 36 to 72 hours on average.

You can also choose to do it at once to quickly set up the amplifier at optimal performance as quickly as possible, or you can use the amplifier as you normally would and allow the sound to improve over time.

How do amplifiers operate?

Amplifiers rely on a microphone that picks up sounds and then converting them to signals that vary in strength, then take the signals, boosting their strength numerous times, and feed them into a loudspeaker, allowing you to hear the magnified output.

The main thing that makes an amplifier unique from other sound equipment such as microphones is that it will not just improve the strength of an electric current; but also reproduce the quality of the original signal as faithfully as possible, even when the signal is varying in volume and frequency. It must also work across a wide amplitude (volume) range, which allows it to reproduce the sound without distortion.

Why is it important to run them in?

Knowing the functionality of amplifiers brings an important question to light – how the run-in process works. This is likely mainly due to changes in the capacitors or transistors when you use them for some time, although there is not much evidence to work with due to lack of extensive research.

Capacitors

Also referred to as ‘condensers’, capacitors are electrical components that passively store electrical charges in electrodes, which are kept separate by a dielectric, a non-conducting material. The capacitor discharges over time when you connect their electrodes to a conducting material like a gel, plastic, ceramic, or paper, which is the case when you set up your amplifier.

Their structure allows them to be useful in audio technology, as they are able to handle rapid changes in voltage, as well as supplying a steady signal to the loudspeakers. This process is known as ‘evening out’, and improves even voltage flows in the amplifier.

When you then change the circuit to an alternative path (the output and input stages), the capacitor will discharge by then. Its capacitance also increases with increasing temperature, which happens when you play music on your amplifier for long periods.

The occurrence of changes in the capacitor is a well-established theory, although there are still people who doubt the extent of changes in a burn-in capacitor. The thought is mainly to do with the capacitor’s dielectric, with many theories stating certain changes in the dielectric. There is also the common thought that audio quality changes you perceive are due to a psychological change, instead of an actual physical change in the capacitor.

Transistors

In the case of transistors, the common rule is that their current flow or internal conductance reduces as the temperature increases if you are using an FET transistor, while a bipolar transistor increases internal conductance as the temperature rises.

When the amplifier is running in, the process will likely result in some physical changes in the transistor, especially in its bipolar, NPN, or PNP junctions. These changes do not need to be drastic either, such as retaining electron charges at these junctions even when you turn off the component. However, if there is a difference between bipolar and FET transistors, it is important to examine all the possible causes.

This also applies to capacitors when they discharge majority of electrons such as during warm ups. However, you will also need to run them in again when you leave the amplifier off for a considerable amount of time, such as a few weeks or months because the electron charges dissipate.

Therefore, this warm up effects are likely due to higher current flow, which results in a better sound from components when at optimal temperatures.

Cables

Many people also include cables as possible components that influence sound quality when you run in your amplifier, although they are also a contentious area. For any sound equipment, the quality of the cables matters due to contact resistance and reliability.

All cables you use in your sound system will have dielectric insulations around their conductor parts. If the dielectric will have partial charge when you connect the amplifier, this may go a long way to reducing the smearing (damaging effect) of the dielectric when you are using the amplifier to listen to music.

Speakers

All speakers, including your amplifier, are meant to operate in specific conditions, and the tone it produces will change as you use the speaker. During the break-in process, its suspension components are the most subject to changes, as they continue to lose the stiffness they initially had – these include the loosening of the rubber surround.

Different speakers will require different break-in times, and this can depend on the environment you use it in. if you live in a predominantly dry, cold area, it will take longer to run in your speaker and amplifier, compared to when you use the equipment in hotter or more humid conditions.

Conclusion

Any hi-fi sound equipment, including amplifiers, will need a running in before use, as this enhances their sound quality over time. This timing will vary on various factors, including the specs of all the amplifiers’ components, which will make it different for each amplifier.