How much do you know about "amps"?

what is an amplifier

amplifier speaker box is referred to as power amplifier. We refer to a basic equipment in the audio system, commonly known as "amplifier". Its function is to amplify the weak driving signal from the audio source or pre-amplifier to generate enough current to drive the speaker. or headphones.

There is a branch in the field of power amplifier is "Hi-Fi power amplifier", Hi-Fi is the abbreviation of English High-Fidelity, its definition is: playback sound that is highly similar to the original sound. Hi-Fi power amplifiers are definitely a bottomless "big pit". It is said that the pit is mainly because of its price. There are tens of thousands or even hundreds of thousands of millions. Another category of amplifier case box is headphone power amplifiers, referred to as "amps". Because some high-end headphones have high impedance, the small player cannot be driven due to its weak driving ability, that is, it cannot be pushed. At this time, an amp is required, which is connected between the player and the headphones to play a role. The role of headphone strength.

Classification of amplifiers box

The classification of box amplifier polos is very confusing. The main reason is that there are too many classification standards for power amplifiers, and the classified amplifier speaker box are interspersed with each other.

In these classifications, we mainly discuss the classification according to the conductive form of the power amplifier tube, which is also the most common way of classifying power box amplifier mini. This classification can be divided into Class A, Class B, Class A and Class D amplifier switch box.

Class A power amplifier means that two or two sets of output tubes in the output stage are always in a conductive state. Regardless of whether there is a signal input, they keep conducting current and make these two currents equal to the peak value of the alternating current. The working mode of Class A power amplifier has the best linearity, each output tube amplifies the full wave of the signal, and there is no crossover distortion at all. The biggest disadvantage of this type of amplifier box cabinet is low efficiency, because there is still full current flowing in when there is no signal, and the power is all converted into high heat. When the signal level increases, some power can enter the load, but a lot is still converted to heat. The advantages of Class A amplifier box cabinet are ideal for replaying music, providing smooth sound quality, round and warm sound, and transparent and open highs.

The working principle of Class B power amplifier is completely different from that of Class A power amplifier. When in operation, the positive and negative channels of the transistor are usually in the off state unless there is a signal input. When the positive-phase signal passes through, only the positive-phase channel works, and the negative-phase channel is turned off, and the two channels will never work at the same time. So when there is no signal, there is almost no power loss. However, when the positive and negative channels are turned on and off, crossover distortion is often generated. Strictly speaking, Class B amp head rack case are not high-fidelity amplifiers. The efficiency of class B power amplifier is about 75%, and the heat production is much lower than that of class A power amplifier.

Class A and B power amplifiers are compatible with the advantages of Class A and Class B power amplifiers, and have balanced the performance of the two, which is a very mainstream type of power amplifier. Class A and B power amplifiers usually have two bias voltages, and a small amount of current will pass through the output tube when there is no signal; when the signal is small, use the working mode of the Class A power amplifier to obtain the best linearity. When the signal reaches a certain level, it will automatically switch to the Class B power amplifier working mode to obtain better efficiency. The advantages of class A and B power amplifiers are that you can get good sound quality, improve efficiency and reduce heat output. The disadvantage is that crossover distortion occurs.

Class D (Class D) amplifier box, also known as dig project amp box, uses a very high frequency switch circuit to amplify the audio signal, which has the advantages of high efficiency and small size. Many Class D amplifiers with power up to 1000W are not very large. However, the work of Class D power amplifiers is complicated. If the power transistors used are not well matched with other devices, the quality of the entire product will be unsatisfactory, and there are few successful products.

These amps all have one thing in common, the amp housing. Amplifier enclosures can bring visual pleasure to the amplifier, high-quality and cost-effective amplifiers can come from YONGUCASE, which is a professional manufacturer of electronic equipment enclosures, large/medium/small/mini amplifiers are available, using high-quality aluminum Profile manufacturing makes the overall enclosure more textured and noble. If you think that the appearance of the amplifier casing is similar, then you are wrong, all amplifier casings must be carefully designed, not only the appearance but also the structural design. Yongucase electronic equipment amplifier enclosure is definitely your best choice.

03 Several important indicators of amplifier enclosure

The main performance indicators of the amplifier enclosure box are output power, frequency response, distortion, signal-to-noise ratio, output impedance, damping coefficient, etc. 

amplifier case box output power: The unit is W. Due to the different measurement methods of various manufacturers, there are some different names. Such as rated output power, maximum output power, music output power, peak music output power.

Power amplifier frequency response: Indicates the frequency range of the amp case and the unevenness within the frequency range. The flatness of the frequency response curve is generally expressed in decibels [dB]. The frequency response of home Hi-Fi mtx amplified is generally 20Hz-20KHz plus or minus 1db, the wider the range, the better. The frequency response of some to amplifier rack mount case has reached 0-100KHz.

Distortion: The idea lamplifier case should amplify the input signal and restore it without change. However, due to various reasons, the signal amplified by theamp rack caser is often distorted to different degrees compared with the input signal, and this distortion is distortion. Expressed as a percentage, the smaller the value, the better. The total distortion of the Hi-Fi amplifier is between 0.03% and 0.05%. The distortion of the guitar amp case includes harmonic distortion, intermodulation distortion, crossover distortion, clipping distortion, transient distortion, transient intermodulation distortion, etc.

Signal-to-noise ratio: refers to the ratio of the signal level to the various noise levels output by the amplifier rack case, expressed in dB, the larger the value, the better. Generally, the signal-to-noise ratio of household Hi-Fi amp flight case is above 60db.

Output impedance: The equivalent internal resistance presented to the speaker is called output impedance..