Do you know the benefits of Home Theater Amplifiers ?

                                     Do you know the  benefits of Home Theater Amplifiers ?

First of all, the home theater power amplifier can be connected to many different playback devices, and it is convenient to switch between different playback devices, including audio players and video players. Audio players include devices like turntables, cassette decks, portable music players, CD players, and network players. Video players include computers, TV set-top boxes, VCRs, VCD players, DVD players, Blu-ray players, high-definition players using hard drives, and devices like PS4 and XBOX.

The connection methods of the above devices are all wired connections. In addition to wired connections, the current home theater power amplifier also supports two wireless connection methods, WiFi and Bluetooth. Just like connecting a mobile phone to a Bluetooth headset, the mobile phone can also be easily connected to the home theater. Power amplifier, use big speakers to play music. In a word, as long as it is a home audio-visual player, including a mobile phone, it can be connected to the home theater amplifier, and it can be switched with one button. Therefore, the home theater power amplifier is also called the home theater entertainment center.

The second main function of the home theater is to decode the digital signals given by devices such as high-definition players and DVD players, and to control the volume at the same time. You don't need to talk about the matter of controlling the volume, but what does it mean to decode digital signals?

Let's give an example. For example, a friend asked me to take a taxi to find him. The meeting place was 39 degrees 54 minutes 26.37 seconds north latitude and 116 degrees 23 minutes 29.22 seconds east longitude. Then if I get in a taxi and throw this coordinate directly to the driver, I will definitely be questioned. I need to translate this purely digital coordinate into a specific location, and then tell the driver: Please take me to Tiananmen Square. In this process, what I do is the decoding of digital signals. Now, a home theater system contains more and more channels, from the most basic 5.1 channels to the more common 11.2 channels, the amount of data calculation is increasing, and the decoding work is becoming more and more complicated. The content is also getting higher and higher.

The third main function of a home theater is power amplification. The home theater power amplifier includes two parts of the circuit, the pre-amplification circuit and the post-amplification circuit. The second function introduced above, digital signal decoding and volume control, is the work of the pre-stage circuit. The job of the post-stage circuit is to amplify the power of the multi-channel signal sent by the pre-stage circuit to drive the speaker to work and make the speaker sound.

Many friends who don't know much about audio equipment feel strange about this link. That is, many friends have computer multimedia speakers at home, such as the Logitech Z520, which is a power cord and a 3.5mm headphone signal cable. That's because these multimedia speakers have built-in power amplifiers.

For example, in the anatomical diagram you see on the screen, there is a toroidal transformer at the bottom of the cabinet, which is a part of the power amplifier. Most of the home speakers do not need to be plugged in. There is no power amplifier inside the speaker, and it must be equipped with a power amplifier.

There are also some home speakers that use a semi-active design, such as some of Difeniti's speakers, which have a built-in power amplifier board. But its built-in power amplifier is only responsible for driving the bass unit of the speaker, and the tweeter and midrange unit still need a home theater power amplifier.

Next, briefly talk about the difference between a receiver and an amplifier. Because many friends in the process of purchasing home theater power amplifiers found that these power amplifiers are divided into two categories, namely receivers and amplifiers. For example, the product classification of Marantz official website is clearly divided into these two categories. In fact, the difference between them is very simple, the receiver has the function of a radio, and the amplifier does not have the function of a radio.

For example, on the Marantz SR5014, the position marked ANTENNA in the lower left corner of the rear panel is the position where the radio antenna is connected. The circular FM is the antenna interface for FM stereo, and AM is the interface for the AM antenna. Generally speaking, the flagships and small flagships of various brands will cut off the radio function. Because high-end models are aimed at consumer groups, the first consideration is sound quality. In order to simplify the wiring and improve the sound quality, the official directly cut off the radio function on the high-end models.

When many new friends see the ports on the back panel of the home theater power amplifier for the first time, the first reaction is basically the same, that is, "What are these things? Why is it so complicated?" In fact, these ports of the home theater power amplifier are not It’s not complicated, just like the control switches on the center console of a car, they can be used for everything. Different brands of amplifiers have the same interface, but entry-level amplifiers have fewer interfaces, and high-end models have more interfaces. Next, I will use this Marantz SR5014 as an example to briefly introduce the functions of these interfaces.

The top row is the HDMI input and output interface. HDMI is the most commonly used and most mainstream interface now, whether it is ATMOS panoramic sound track or 4K resolution, it is inseparable from HDMI. Like the Marantz 5014, there are 7 inputs and 2 outputs on the back panel, which means that 7 playback devices with HDMI ports can be connected at the same time, from 1 to 7 are TV set-top boxes, DVD players, Blu-ray players, game consoles, Media player, backup equipment, CD player. It is emphasized here that these input ports are exactly the same. For example, your XBOX game console can be connected to any one, as long as you select the corresponding input channel on the remote control.

There are 4 digital audio signal input ports, 2 digital coaxial channels, and 2 optical fiber channels. Before the HDMI interface appeared, VCD disc players and DVD disc players generally used these two digital signal input ports. Some friends have TV set-top boxes at home, which may be older models, without HDMI output, but with coaxial and optical fiber outputs, which can be used to transmit the sound to the power amplifier, and use the speakers to play the audio of TV programs.

The video signal input port is a composite port, 2 in and 1 out, and the definition is the worst, so don't use it if you can. There are also three sets of red, blue and green ports here, which are color difference ports, two in and one out, and three lines are connected to one device. The component port can support up to 720P resolution. Some old TV set-top boxes generally have component output. If there is no HDMI output, component is the first choice.

Analog input to this part of the port. If your playback device only has this kind of red and white lotus head, or only 3.5mm headphone output, you can connect to this part of the port. For example, CD players, the output ports of CD players are all this kind of lotus head. Or like some portable MP3 players, use a 3.5mm to lotus head signal cable to connect here, and you can play music through the speakers.

The pre-stage output port is used to connect an external independent post-stage power amplifier to obtain more power. Generally speaking, it will be used by audiophiles, or it will be used by high-end custom home theaters.

Speaker terminals. One red and one black binding post represent positive and negative poles respectively, and two binding posts are connected to a speaker. Novice Xiaobai friends should pay attention to the fact that all brands of home theater power amplifiers can be directly connected to bare wires or banana plugs, but most of them cannot use Y plugs. If you don’t know how to connect bare wires or banana heads, you can search for the account Penguin Fever on Douyin. I made two small videos for demonstration.

Infrared control interface, data exchange interface and a 12V trigger interface. These three interfaces are used in system integration and engineering control, we don't usually use them, everyone just needs to understand them.

After talking about the interface of the power amplifier, let's talk about the types of home theater power amplifiers. In terms of product form, home theater power amplifiers can be divided into two categories, namely integrated power amplifiers and split front and rear power amplifiers. Like this Marantz 5014, the pre-stage circuit and the post-stage circuit are all in one case, it is an integrated power amplifier. The so-called split-type front and rear power amplifiers are to put the front-level circuit in one chassis and the rear-level circuit in another chassis to make two machines.

Why do you want to do this, because the front-stage circuit is very sensitive to external electromagnetic interference, and the working characteristics of the rear-stage circuit determine that it will generate a lot of electromagnetic interference, so in order to further improve the sound quality, they are simply separated. For example, Marantz’s AV8805 preamp has the same front panel as the Marantz SR8015, but if we look at its back panel, we can see that it has no speaker binding posts, so it must be used with a power amplifier.

As for the post-stage, 5-channel post-stage power amplifier, we can see that its interface is very simple, the upper part is 5 signal input ports, and the lower part is 5 sets of speaker binding posts. This kind of independent rear stage does not mean that it must be matched with a pure front stage, as long as the AV power amplifier has a pre-stage output, it can be used with a rear stage, but we must also consider the cost-effectiveness issue.