Indeed, it was amplifiers that for a long time remained the last stronghold of analog circuitry; But recently, the “military actions” of “digitals” on this “front” have noticeably intensified, and it seems that the fate of analog amplification equipment is already predetermined - it will remain an antique for the mass listener and will please the vanity of fans of high-budget hi-end solutions. Whether we want it or not, now no one has any doubt that the long-term conflict between analogue sound and “digital” should very soon come to its logical conclusion with the almost complete victory of digital technology on all fronts - including at the front sound amplification. But can digital amplification technologies completely defeat analog amplifiers now?
How does an analog amplifier work?
Let's first look at what the process of processing an audio signal looks like in an ordinary amplifier, which, in general, is appropriate to call analog. Sound originates in an external signal source, which can be a CD/DVD player, cassette recorder, tuner or turntable for vinyl discs - the type of signal source plays virtually no role here; it then goes to the input stage of the amplifier.
The incoming signal is analyzed, if necessary, some adjustments are made to it (for example, using a tone block, the saturation of low frequencies or, conversely, high frequencies is increased), and then “scaled” using special analog amplification circuits. Thus, we obtain an “enlarged copy” of the original signal, in an unattainable theoretical ideal, one hundred percent identical to the incoming signal in everything except its amplitude, which is ready to be fed to the output stage in order to be sent to the speaker systems and spill out there into the ocean of sound space so desired by us. Voila! The whole process seems simple, natural and harmonious. But, as often happens, all this is beautiful only in theory. But what do we get in practice?
In practice, the picture is much more complex. For more or less reliable sound reinforcement with minimal distortion of the useful signal, it is necessary to achieve coordinated operation of a large number of well-selected and competently tuned high-quality analog components inside the amplifier. Their operating parameters should not be subject to changes depending on the time of their own heating or from any parasitic noise. (Agree, it would be very strange to read in the instructions for the device a phrase similar to this: “The high-quality operation of the amplifier is guaranteed no less than half an hour after it is turned on and for no more than three hours of its use,” although it is largely true.) This can only be achieved using expensive circuitry. Failure or deterioration of the parameters of one component instantly affects the sound quality, sometimes fatally. Also, analog audio components are highly dependent on a high-quality power supply, which, in order to avoid interference with parasitic signals, must be supplied inside the system truly masterfully.
TPA3255 Bluetooth, 600 W, Full frequency/subwoofe mode switch, power supply.
TPA3255 amplifier – link
Everyone can find for themselves what they want. There are even class D amplifiers with fans.
link
And those who are not fans of Carloson can take exactly the same one, but without fans.
Operating principle of a digital amplifier
From the point of view of efficiency and reduction of distortion, it is better if the amplifier operates in the so-called key mode, that is, the voltage at its output can take only two values. But how then will the complex signal shape be transmitted?
This is done as follows. A digital amplifier supplies energy to the speaker systems in portions. This is done with pulses of different widths. The wider the pulse width, the more energy is delivered. At the same time, the pulse repetition rate differs by two or even three orders of magnitude from the maximum frequency of the amplified signal, which makes it possible to transmit the most subtle nuances of sound. Between the amplifier and speaker systems there is a special filter that smoothes out the pulses in the form of which energy is supplied. As a result, the signal no longer arrives at the speakers in a pulsed form, but in a regular, analog form.
Thus, at the input of the digital amplifier there must be some device that converts the value of the analog signal into the pulse width at the output. This is called the principle of pulse width modulation (PWM). In principle, PWM can also be implemented in an analogue way - such amplifiers were created back in the 70s of the last century, but their sound quality was poor. Only digital technologies made it possible to implement PWM without significant damage to sound quality. Nowadays, digital amplifiers also use some other, more complex than PWM, principles for controlling output pulses, which make it possible to achieve even higher amplification accuracy. But the essence remains the same - the signal is converted into pulses, which are amplified and passed through an anti-aliasing filter, again turning into an analog signal.
The most modern solution is the conversion of information directly recorded on a digital medium into pulses for digital amplification. This approach allows for high sound quality.
Choosing modern digital audio amplifiers with DAC on Aliexpress
Today's post is dedicated to combination devices for a modern HiFi sound system. It's a good idea to combine a DAC and a digital audio amplifier in one device - a minimum of conversion, digital processing capabilities and compact dimensions. Such digital amplifiers have a large number of inputs, including a Bluetooth module, a variety of sound settings and sufficient power for bookshelf sound systems.
Every year, digital devices are replacing analog ones, and this is also noticeable in audio technology. Class D amplifiers with a digital signal input have appeared (as an example, you can see the TAS5614 from Texas Instruments) working in tandem with a multi-channel audio processor (modulator).
The abundance of digital inputs of the built-in DAC allows you to connect such an amplifier to any source: laptop, game console, HD player, smartphone and PC. What you need for a modern sound system. And some models immediately have support for streaming services - endless content.
Let's consider various options for digital amplifiers, but at a reasonable cost on the AliExpress site.
FX-AUDIO D2160MKII
Find out the price Previous version
The selection opens with an excellent option from FX-AUDIO, the updated FDA (fully digital amplifier) D2160MKII. Maximum power 150 W. Power supply DC 36 V/6A included. The front panel is available in black and silver.
The device is built on chips: TAS5614 + MCU STM32 + DSP TAS5548 + PCM1808 + AK4118 + CM6642 + CSR8675. And a MAX9722 headphone amplifier.
To adjust the sound, there is a tone block, loudness compensation and an equalizer with five settings.
The changes affected the Bluetooth 5.0 chip - now it is a CSR8675 with support for APTX-HD LDAC, 24Bit/96kHz and an output for an active subwoofer has appeared.
I had the 1st version of this model - it sounded very decent. There is a “transparent” DAC and an amplifier of sufficient power.
D802C PRO
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Another model from FX-Audio that cannot be ignored. The D802C PRO also gets a makeover for 2022.
It has less power and size than the D2160; The STA326 amplifier chip produces about 80 Watts maximum into 4 ohms.
Other chips: AK4113 + CM6642+ QCC3034 + NFC + ADC Wolfson WM8782S. There is an equalizer and a remote control.
Signal inputs: AUX, optical, coaxial, PC-USB and Bluetooth 5.0 with APTX.
There is a black and silver front panel of the device and in the lot you can buy an amplifier without a DC 32V/5A power supply.
Arylic A50
Find out the price of A50+
Here comes the streaming amplifier, Arylic knows how to do it! There is a full set of functions: LAN, Bluetooth 5.0, USB, WiFi, Airplay, DLNA, UPNP, multiroom and a digital amplifier on the STA326 chip from ST with 50 W per channel. And all in a compact case 120x110x40 mm.
The device has two antennas: 2.4G WiFi and Bluetooth and has a 100M LAN for your home network. Power: 24 V, 4.15 A included.
The A50+ version has an active subwoofer output.
For Internet services, you use your smartphone with the 4STREAM application, and there is also a regular remote control.
An excellent option for building an audio system with streaming services and wireless technologies.
Aiyima D05
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I like this digital amplifier with DAC option. Many inputs, max 120 W per channel and high-quality Bluetooth 5.0 and all this with a normal design and for reasonable money. The only drawback is that there is no headphone amplifier.
The model is built on microcircuits CM6642, TAS5508, TAS5352A, QCC3008, CS8422, WM8782. Power supply included with parameters 32 V 5 A. Dimensions: 183 × 128.5 × 37 mm.
Ease of control is added by a small OLED screen and remote control.
To fine-tune the sound character there is: an equalizer with 5 settings, a tone block and loudness compensation.
SMSL SA300
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Option of a digital amplifier from SMSL in an unusual colored case 70x73x188 mm. The highlight: the amplifier chip is MA12070 from Infineon Technologies, 80 W into a 4 Ohm load. There is a subwoofer output. The volume is controlled by the NJW1194 chip.
The sound can be adjusted, there are several equalizer modes and high/low frequency adjustment. Remote control included.
Digital inputs: micro USB for PC/laptop and Bluetooth 5.0 on a Qualcomm chip with support for the AptX codec.
The lot has a choice of three body colors and fast delivery from a warehouse in the Russian Federation.
LOXJIE A30
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Another interesting option in a stylish aluminum case on the new MA12070 amplifier chip from Infineon Technologies and volume control on the NJW1194.
Total dimensions: 151 x 170 x 38 mm. Remote control and 24 V power supply included.
LOXJIE A30 is an 80 W stereo amplifier with an output to an active subwoofer and at the same time a headphone amplifier, and the built-in DAC is here on the ESS Saber ES9023. Oh, and also Bluetooth on a high-quality Qualcomm QCC3008 chip.
High-quality workmanship, design and well-fitted IPS screen. A30 will look harmonious on the table next to a PC and mini speakers. HiRes DAC and good sound will complement the pleasant experience.
Fosi DA2120A
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The selection is completed by a compact amplifier with a DAC from Fosi. Dimensions: 134x130x34 mm.
But despite its size, the DA2120A has all the necessary digital inputs (USB, Optical, Coaxial), Bluetooth 5.0 apt-X and a 50 W Class D amplifier with subwoofer output.
DAC for the model (USB CM6642) with parameters 192KHZ/24BIT. Bluetooth chip QCC3031. AUX line input on 3.5 mm jack.
For ease of control, the DA2120A has a remote control and a small OLED screen. The sound can be adjusted using an equalizer, loudness compensation and tone control.
Fosi's price is lower than others, especially if you buy without a 24 V switching power supply.
I hope the selection of digital amplifiers with DACs for sound systems was useful and you will choose an option to suit your taste (hearing) and budget.
Happy shopping! Don't forget to apply AliExpress coupons and discounts.
Brand overview
An electronic audio amplifier is an opportunity to enjoy beautiful music with 100% pure playback. If you want to replace the old analogue with “digital”, then you should choose only quality. And it is guaranteed by popular brands:
- NAD M2 is called by experts a universal amplifier. True, it only works with digital signals, so there are no intermediate converters in the circuit;
- Musical Fidelity AMS35Р is distinguished by a perfectly even frequency amplitude, which ensures high sound quality;
- Electrocompaniet ECI 5 MKII, thanks to innovative technologies, allows you to get real sound with good resolution and dynamics.
Digital amplifier NAD M2
There are other models that provide high quality - Denon PMA¬A100, Pioneer A¬A9¬J, Parasound 2250¬B, Kenwood RA¬5000. The equipment also attracts with its designer look, organically fitting into the interiors of modern apartments.
