About the power amplifier

                                             About the power amplifier

1. Choose a combined type or a split type?

Regarding how to choose a power amplifier, you first need to determine whether to buy a combined power amplifier or a pre/rear independent power amplifier.

The advantage of the integrated power amplifier is that it is easy to set up, easy to operate, and save space. The chassis has built-in pre-amplifier and post-amplifier, and the manufacturer has optimized the matching of the front-end and back-amplifiers, saving users the effort of choosing different front-end and back-stage power amplifiers.

In the scheme of pre-stage + post-stage, the pre-stage is mainly responsible for input selection and volume control, etc., and the post-stage focuses on power amplification. The advantage of this solution is to ensure that the sensitive pre-stage circuit is far away from the electronic interference of the high-current post-stage power amplifier. In addition, if it is equipped with an independent power supply, the sound quality can be further improved.

If you want the pre-amplifier and post-amplifier to complement each other, the easiest way is to choose the same brand series products, because the brand has already carried out better tuning for the front-rear amplifier match. If you want to buy different brands of pre-amplifiers and post-amplifiers, the sound performance of different combinations will be very different. The more effective way is to keep trying.

Regarding the matching of sound sources and power amplifiers, the most basic theory is to choose according to their sound orientation. For example, if your CD player sounds brighter, then the sound orientation of the power amplifier you choose should be darker.

2. About the collocation of power amplifier and speakers

The speakers that match the power amplifier are very important, and there are a few collocation issues that are worth considering. Do you know what "75 watts into 8 ohms" means? Let the editor answer the basics for you one by one.

The matching of speakers and power amplifiers not only involves the power output of the power amplifier (that is, how many watts the output power is per channel), but also involves impedance (in ohms) and sensitivity (dB).

Impedance reflects how easy it is for the power amplifier to drive the speaker; sensitivity reflects the volume that the speaker emits when driven by a given power.

The standard way to measure the output power of an amplifier is to connect it to an 8 ohm resistor and measure the maximum power before distortion. However, the electronic load of the speaker does not have a fixed value like a simple resistor, so the output power measured at 8 ohms is for reference only.

Existing speakers generally use db/w/m as the unit of speaker sensitivity, that is to say, in the speaker system, input 1 watt of power, and test the sound pressure at 1 meter in front of it. In this way, the sensitivity value of the speaker can be obtained. Under normal circumstances, the sensitivity of the speaker is generally between 83db/watt/meter and 92db/watt/meter. Don’t underestimate the difference of 9db. Twice as much to get the same volume. In other words, the volume of a speaker with a sensitivity of 92db/watt/meter at 10 watts of power, and a speaker with a sensitivity of 83db/watt/meter requires 80 watts of power to be the same.

Many audiophiles tend to buy a power amplifier with the highest power that the price can afford, but the first thing you should consider is to buy a speaker with higher sensitivity.

However, both the output power of the power amplifier and the sensitivity of the speaker are just references, but the best way to judge is to personally listen to the effect of the power amplifier and your audio system.

3. Regarding the placement of power amplifiers

Once you've settled on the amp you want to buy, the next question is where are you going to put it/them? What you put the stereo power amplifier on has a great impact on its sound performance. We do not recommend that you put the power amplifier on ordinary furniture such as IKEA or directly on the ground, but put it on a special HiFi audio stand. When choosing a HiFi speaker stand, don't just pay attention to the appearance, because different materials will show different sound characteristics, so this is also something you need to consider.

Generally speaking, a glass HiFi speaker stand will make the sound appear straightforward, while a wooden HiFi speaker stand will make the sound appear warmer and rounder.

The amplifier will continue to generate heat when it is in operation, so you will want to keep a few inches of cooling distance between the amplifier and the wall/HiFi speaker stand to avoid overheating the amplifier.