Almost all gadgets - phones, tablets, players, laptops have headphone outputs, they work and provide sound. However, it is interesting that with different amplifiers at the output, a completely different sound is obtained at the same volume on the same headphones. So what's the trick? A separate amplifier enhances detail, changes the atmosphere of the sound, ensures maximum match with the source, and minimizes distortion.
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Replacing headphones may not always meet expectations in terms of sound quality, and connecting an amplifying device invariably guarantees a decent result.
The amplifier receives the audio signal from the source and amplifies its current and voltage to the required level of the headphones for high quality reproduction.
Modern smartphones are capable of supporting such a standard, and Hi-Res is moving out of a narrow segment niche into a big life.
The sound quality has a higher frequency than CD. The Hi-Res format is characterized by a sampling rate of 96 to 192 kHz, with a sampling rate of 24 bits. For CD sound the parameters are 16 bit and 44.1 kHz.
The sampling rate is the number of times a signal is sampled per second in order to convert it to “digital” from an analog state.
The D / A converter is part of the source-DAC-headphone circuit to increase sound quality. In headphones and speakers, sound reproduction is carried out using an analog signal. Audio discs and hard drives store files in digital format.
From which it follows that in order to obtain sound in the headphones, digital-to-analog conversion must occur. The built-in DAC chip is an integral part of amplifiers.
A balanced audio connection uses a balanced line connection type. The area of use was originally at concert venues, at recording studios, since it gives the advantage of connecting through long cables that do not allow external interference.
A balanced connection uses a phase-anti-phase-ground scheme, which allows you to “subtract” interference while maintaining the signal.
The dimensions of the device indicate its power, which depends on the output voltage, maximum output power and resistance.
Full-size headphones can hardly be adequately pumped by a small-sized amplifier. The ratio of the sensitivity of the headphones to the final volume level determines their output:
The internal impedance of the headphones must correspond to the parameters of the amplifier, otherwise the output stage will overload and the distortions, both nonlinear and linear, will increase.
In total, three classes of amplifying devices are distinguished:
"A" - amplifiers of the best quality and value, without distortion and maximum linearity. The negative side of the class is overheating and low efficiency. In the final stage, the quiescent current is several amperes.
"B" - devices operate at half-cycle, half of the wave is "extinguished", but the efficiency is more than 50%.
"AB" is an intermediate class between the two above, a characteristic feature is the reduction of distortion by displacement at the beginning of the signal. The maximum quiescent current value is up to 150 mA.
The entire numerous range of headphone amplifying devices is divided into 2 types:
Almost all models have semiconductor circuitry, but there are also tube devices.
The main task is to combine the existing headphones with the purchased amplifier, or set the task of simultaneously purchasing both devices. Headphones can be high-ohm - from 100 ohms, and low-ohm, not every power is within the power of a "weak" model. The good sensitivity of high impedance headphones does not directly affect the volume level.
Manufacturers occupy certain price niches, the following price groups can be distinguished:
Amplifiers with a built-in DAC have advanced functionality, this applies to:
The sound is rated according to the following main parameters:
Famous brands try to adhere to a certain line of style and design. The desire for lightness and mobility of models remains in demand, bulky systems have sunk into oblivion.
For stationary devices, the priority is strength and reliability, for portable devices, size and thickness come first with the possibility of a "sandwich" configuration.
When comparing several amplifying devices in terms of loudness, they use voltage parameters that are measured by dBV, it is the difference in voltage numbers that indicates the loudness delta in dB.
The main erroneous calculations are:
The company entered the global market in 2007 and won the trust of buyers, first of all, with a product from the headphone amplifier series. The ideal price-quality ratio was decisive in taking the leading positions. The company regularly releases new products and is distinguished by the rapid growth of customer demand segments. The innovative ideas of the developers are based on the gained production experience. The priority areas are quality, ergonomics, creativity, practicality. One of the brand's most recent breakthroughs has been a fourfold increase in production capacity.The company has also strengthened its quality control and finished product testing sector.
A stereo amplifier from China with a power of 0.112 W, with a built-in battery, belongs to high-definition gadgets.
FiiO Q1 Mark II | |
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Channels, number | 2 |
Front channel. Power, W | 0,112/0,075 |
Playback frequency 3.5 output. Range, Hz | 5:55000 |
Balanced output playback frequencies. Range, Hz | 6:80000 |
DAC | AK 4452 |
Accumulator, built-in, mA / h | 1800 |
Full charge, t, h | 4 |
T (time) of work from one charge, hour | 10 |
A stereo headphone amplifier with two outputs, built-in DAC, became the flagship. Balanced circuitry and reading all XMOS formats as well as wireless Bluetooth 4.2 (aptX) have taken the brand to a whole new level.
FiiO Q5 | |
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Channels, number | 2 |
Frontal channels. Power, W | 0,47/0,23 |
Playback frequency 3.5 output. Range, Hz | 5:50000 |
Balanced output playback frequencies. Range, Hz | 5:50000 |
DAC | AK 4490EN * 2 |
Bluetooth | CSR8670 |
Accumulator, built-in, mA / h | 3800 |
Weight, kg | 0.2 |
T (time) of work from one charge, hour | 25 |
An amplification device with Bluetooth and DAC from a Chinese manufacturer is a popular model in the budget class.
Shanling UP2 | |
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Channels, number | 2 |
Signal to noise ratio, dB | 116 |
DAC | + |
Bluetooth | + |
Bitness, depth, Bit | 24 |
Weight, kg | 0.26 |
Output power, mW / ohm-W | 67/32 |
Portable stereo device with built-in DAC and support for popular formats produces very high quality and clear sound.
Sony PHA-2A | |
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Channels, number | 2 |
Headphones, impedance, Ohm | 8:600 |
DAC | ESS Saber ES9018S |
Sampling, frequency, kHz | 384 |
Frequencies, range, Hz | 10:100000 |
IOS mode KHz / bit | 48/24 |
KHz / bit optical input mode | 192/24 |
Weight, kg | 0.23 |
Output power, mW / Ohm-W | 100/32 |
Output power - balanced, mW / Ohm-W | 320/32 |
The stereo sound portable amplifier has a USB connection to a PC.
OPPO HA-2 | |
---|---|
Channels, number | 2 |
Connector, mm | 3.5 |
DAC | + |
Frequencies, range, Hz | 20:200000 |
Racks | USB, Micro-USB |
Power, mW / Ohm | 300/16; 220/32; 30/300 |
Weight, kg | 0.175 |
Stereo amplifier on a semiconductor circuit for a PC has good sound and wide functionality, perfect for computer games.
Sennheiser GSX 1000 | |
---|---|
Channels, number | 2 |
Headphones, max impedance, Ohm | 150 |
Headphones, min impedance, Ohm | 16 |
Control Panel | sensor |
Headphone output, quantity | 1 |
Weight, kg | 0.39 |
Output power, mW | 1000 |
Small-sized stereo amplifier from the Chinese manufacturer - the flagship of the budget group.
FiiO Olympus 2-E10K | |
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Channels, number | 2 |
Frequency range, kHz | 20:20000 |
Voltage, corridor, V | 7.39 |
DAC model | Texas Instruments PCM 5102 |
Signal-to-noise ratio, dB | 105 |
Headphone outputs, mm | 3.5 + coaxial + linear |
Weight, kg | 0.78 |
A stationary stereo sounding device with a built-in DAC, high quality and at an affordable price has a lot of positive reviews.
S.M.S.L M3 | |
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Channels, number | 2 |
Connector, mm | 6.3 |
DAC | + |
Signal-to-noise ratio, dB | more than 120 |
Discrediting, frequency, USB, kHz | 32/384 |
Discrediting, frequency, coaxial, optical, kHz | 32/192 |
Weight, kg | 0.6 |
Despite the abundance of amplifying devices, their manufacturers, price and functional lines, you can find a lot of examples of the wrong choice on the Internet. Hopes for quality, volume, power, playback control are not justified. It is the abundance of offers and insufficient technical training of the user that sometimes leads to waste. In the case of choosing a headphone amplifier, the proverb becomes especially important: "Measure seven times ..."