By chance I received rear speakers from a home theater, and I wanted to use them as computer speakers. To connect passive speakers you need an amplifier, which is why I purchased a PAM8610 module. The module is simple, quite powerful and cheap. Thanks to the 12-volt power supply, it is easy to record it from a computer power supply and even integrate it into the system unit. The PAM8610 is described in detail on the Internet, for example here: However, in the standard connection I encountered difficulties in the form of strong noise. Needed some work...
First, I connected the amplifier in the usual way: a cable with a minijack through a dual 10 kOhm potentiometer. And I was very disappointed high level noise, which was noticeable even with the volume control at its minimum position. Even worse, the speakers responded with crackling and grinding noises to the movement of the wireless mouse. Experiments with replacing the power supply with a laboratory one, and then with a battery, did not produce any effect. But when I connected an mp3 player instead of a computer, the noise decreased significantly and the tone became less annoying. It became clear that the problem was in the signal source and excessive amplification. According to rough estimates, a 10-fold gain (20 dB) is sufficient, since the computer produces a signal with an amplitude of approximately 1 volt, and an amplifier with a 12-volt power supply can output approximately 10 volts to the speaker. All that remains is to figure out how to reduce the gain. Reading the documentation helps in this matter. I recommend the old datasheet. For some reason, the document on the manufacturer’s website diodes.com is missing some pages. The PAM8610 has a DC volume control function, in other words, volume control using DC. It works like this: the VREF pin is supplied with a voltage corresponding to the maximum volume, and the VOLUME pin is supplied with the current voltage. The entire range is divided into 32 intervals, each of which corresponds to a certain gain. For example, if VREF=5 volts and VOLUME=3 volts, 3/5*32 = 19.2, the gain should be looked at in the 20th line of Table 1: 21 dB. But you don’t have to bother with calculations at all, but simply send the VOLUME signal through variable resistor resistance 10k-100k. In addition, this approach allows you to use the most common resistor. In the classic regulator circuit, a special dual resistor with a logarithmic characteristic is placed at the amplifier input. If you use a regular linear one, the volume is adjusted unevenly: at first it increases sharply, and then practically does not increase. Even with double resistors, the resistance may vary unequally, then the speakers sound at different volumes.
Unfortunately, the specified module does not provide contact pads for the volume control, so you will have to cut the tracks. The extreme terminals of the potentiometer must be soldered to ground and the +5V mark, and the middle one to vol. 
But that's not all. To further reduce interference noise, you need to add a filter low frequencies. I limited myself to an RC circuit at the input, soldered SMD capacitors to the board, and mounted resistors. At the same time, I replaced the ceramic input capacitors with film capacitors. The result is the following diagram: 
R1 and C3 form a low-pass filter with a cutoff frequency f =1/(2π*R1*C3). At the indicated ratings, it is 72KHz. In general, the indicated denominations can only be used as a starting point, and the final ones can be selected experimentally by ear. Capacitance C1 is selected based on the low frequency cutoff frequency f =1/(2π * R *C1), where R is the input resistance of the amplifier from Table 1 in the datasheet plus R1. With the indicated ratings and the maximum position of the volume control, the input impedance of the amplifier is 21 kOhm, and the lower cutoff frequency is 34 Hz. This is more than enough for my 70Hz-20kHz speakers. If you need to expand the range towards the bottom, you need to increase the capacity of C1. But you shouldn’t get too carried away so as not to overload the speakers. Resistors R3, R4 are jumpers that are installed instead of original ceramic capacitors. 
Redesigned board. 
Amplifier assembly. The housing is the cover from the distribution box. The heatsink is made of an aluminum strip, to which the board is pressed through a thermally conductive gasket. The input capacitors and resistors are soldered by surface mounting; after final adjustment, they are filled with hot glue. 
The result is this design.
Unfortunately, I cannot provide test results to the RMAA. Since this amplifier is made using a bridge circuit, you need to measure the signal at the speaker terminals, and not relative to ground. That is, you cannot connect the amplifier directly to the line input of the sound card. Need a professional sound card with a balanced input or a separate amplifier for measuring the differential signal.
As for subjective feelings, I am completely satisfied with the result. The sound is comparable to SVEN “wooden” computer speakers. But the speakers are powered by system unit and turn on and off with it.
PAM8610 fully justified itself. The only remark is that you don’t need to take the cheapest board so that you don’t have to redo it later. Next time, if I need to do something similar, I will look for a board with wiring for a volume control.
Hi all.
In this review we will look and listen to the PAM8610 class D amplifier. It's made for portable acoustics, on its basis you can assemble a long-playing loud speaker system.
This is the cheapest copy available on Aliexpress.
Let's start with the basic technicalities. characteristics
Power - 10w*2 at 8 ohms, and 15w*2 at 4 ohms (power values at 10% distortion)More details are in the datasheet.
Power supply 7 - 15v (recommended 12v 3a)
Class D
Efficiency: 90%
Dimensions only 29mm*25mm 
Real photo 
It is very small, the chip is generally tiny)
Soldered the wires and fixed them with hot glue 
I connected it to the power supply, turned it on and got a terrible noise. (speakers 15 ac 109)
Need a volume control. But until I connected it, I decided to listen to how it plays.
Connected to the player - the noise is less, but still present.
After listening for a short time at low volume, the sound was with noticeable distortions and overtones, in general it was not ice at all.
When you turn it up louder it’s much better, but you can still sometimes hear distortion at certain moments in the music.
“Well, okay,” I thought, “I’ll listen to it fully when I find and attach a volume control, in case the noise bothers me.”
And then I remembered that I have a dead usb speaker. I removed a variable resistor marked b50k (50k, linear) from the board, and removed the rest. I connected everything as needed, fixed everything with hot glue. It turned out like this 
I didn't find the switch, so I left it as is. I wanted to connect a standard LED, but it is 5V, and the power supply is 12V. I didn't bother. 
I just ran the wires out the back. 
Now there is no noise.
I started listening - at low volume the distortion went away, which means the interference was really interfering.
I connected the multimeter in ammeter mode. I turned the music on full blast until the distortion started. Consumption ranges on average from 300 to 700ma. I turned on the music and the bass - maximum 1.3a, average consumption 1a.
I noticed a peculiarity - when power is applied, the volume increases smoothly.
In terms of volume and sound quality - the volume is enough for a home, to my ears the quality is not bad. There is bass.
And if you listen on the street, you don’t need anything more.
A short review and how it plays by watching the video
In my plans I also want to add a converter so that it can be powered from a power bank. The required converter is already on its way. I don’t know what will happen, but it will be interesting)
In general, this amplifier impressed me, like the previous pam8403)
I was pleased with the sound quality.
REVIEW OF POWER AMPLIFIERS
POWER AMPLIFIER PAM8403. 2 CHANNELS EACH 3 W.
This power amplifier is distinguished by its miniature size and relatively high output power, since it is a class D amplifier. The PAM8403 chip has two bridge channels providing an output power of 3 W into a 4 Ohm load with a supply voltage of just 5 volts. The oscillation frequency is 260 kHz, which allows you to cover the audio range with a rollover at the edges of only 3 dB.
The circuit diagram of a miniature power amplifier is shown below:
The assembled amplifier board looks very compact and does not require any explanation about the connection:
Judging by the number of orders, these amplifiers are no longer sold by the piece, but by the kilogram...
And of course, a few reviews on this amplifier:
Delivery was on time, the amplifier itself made a splash on my mind, how can such a piece of crap work so well!? I planned to connect it to small speakers, but as it turned out, it pulls great and the speakers are more powerful, a real thing!
I don’t know how it’s 15 watts, but it works clean and loud
I received 2 copies. I've only checked one so far. I loaded the speakers with S-30. Power source 12 volts 4 amperes. Signal source line output computer. To the ear, the sound is very decent. I didn’t do any characterization, and it’s not necessary. It couldn't be better to use as an amplifier for a computer, TV or other small portable speaker system. There is no noise when connecting the input with a shielded wire.
the expected result coincided with many reviews, the amplifier operates from a 9 and 12 volt unit, when connected to the equipment, the background disappears, high-quality cords and cables will help... you can load it to full, but a radiator is very necessary, when loaded at 50% everything is ok. I inserted it into an external car speaker, for moments on vacation when connected to a laptop, it works. When listening to music from a smartphone, it began to “swallow” load peaks by more than 80% and reduced the sound by itself,
Amazing amplifier! I used it in my DIY mobile speakers and it works very well! The sound quality is excellent. There is some noise, but it's quiet and you can't hear it when you're playing music, for example. I run it on 2s 7.4 Lipo. he plays loudly, but it depends mainly on what speaker systems you use. Recommended so much!
Delivery took less than a month (I paid extra for delivery). The amplifier is working (don’t attach three padded jackets to it, otherwise it will burn the fuck out, but if you hook it up, listen at the second volume level (if from a phone)). The amplifier is working and for such a price it doesn’t carry badly (with cooling it can stretch a Vega speaker to middle volume (from the phone). There was no need to contact the seller. From me 5 stars to the seller P.s. I played music from the phone that HAS EQUALIZER FX!!!
Updated reviews
and yes, I soldered the aux input, and when you pull out the plug it makes a lot of noise (well, pretty much everywhere), I asked a friend and he said that it should be so, well, I resigned myself, and before pulling out the plug I will turn off the power.
With high-quality food, the sound is very high quality. When the SW jumper is closed, the volume gradually fades to zero, such as the mute function. When opened, the volume smoothly returns back.
The sound quality is worse than I expected
The board does not use the volume control output of the microcircuit. This is not an amplifier, but an interference receiver!
The product was poorly packaged due to which several parts were broken off during transportation. The result is inoperability of the amplifier.
POWER AMPLIFIER FOR TDA2030. 15 W.
Fans of traditional class AB can recommend power amplifiers based on the TDA2030 chip. This amplifier has deservedly gained popularity, since this chip requires a minimum of external components and provides quite high-quality sound.
Please note that most amplifier boards are designed to connect single-supply power. Single boards with a small radiator are not designed to receive maximum power:
Personally, I am more impressed by boards for self-assembly of an amplifier. They are somewhat more expensive and you will have to solder yourself, but this option has much greater versatility. The board of such a power amplifier looks like this:
There are quite a few options for amplifier designs on the TDA2030, ranging from the single-channel options given above to 2.1 systems, where two microcircuits are connected as a bridge for the subwoofer.
For those who have problems purchasing radio components, the most optimal option would be one with an already installed tone control and volume control; this option requires a bipolar power supply:
The amplifier on the TDA2030 chip has the following characteristics:
Maximum output power 18W
Supply voltage 9...24 V (the microcircuit can operate up to 36V supply, but you should check the voltage of the electrolytic capacitors - the Chinese can put capacitors at a voltage of 16V, but this is not enough).
Load resistance 4...8 Ohm
With an output power of up to 10 W, the THD level is no more than 0.1%.
There are also power amplifiers based on the TDA2050, but for some reason they are too expensive.
From personal experience, here are some tips that you can ignore:
There is no need to receive more than 60 W from one chip - it is difficult for it to transfer heat to the radiator.
There is no need to fence bridge and parallel connections - this greatly reduces the reliability of the amplifier.
For those who have collected a couple of copies and are ready to prove with foam at the mouth that everything works, I will tell you that I have collected more than a hundred different versions of amplifiers on the TDA7293 and I can report: everything really works, but in order for it to work RELIABLE additional measures are required, so For radio amateurs on a budget, it's better not to take risks.
Well, a few reviews:
checked the amplifier, quality product, I advise the sound is good
Great amp! I connected the trans and that's it. Walked for a long time
I installed it in 101 instead of the old transistor ones. for s 90 it’s even enough.
Everything is fine. Delivery on the last day of the first defense. The seller extended it for 40 days. But it wasn't needed. The quality is good. I checked everything. Super sound quality. 5+
I checked everything, everything works, the soldering quality is normal, I just had to wash off the flux
The seller did not send what I ordered. 300 rubles somewhere fucked up... It's a shame. Doesn't respond to SMS
Updated reviews
At first the seller sent the wrong product. After the dispute was closed, I immediately sent my order 1st class to M.O. 6 days. Thank you very much to the seller for your understanding. 5☆☆☆☆☆
They arrived quickly, are already working, fully correspond to the description. Good signet, track layout, no noise, no noise.
One of the two amplifiers arrived in normal condition, the second sparked and smoked and there was a sharp hum in the speaker. I don't recommend it, the quality is crap...
I ordered two amps, one working, the other burned out in a bright flame
The product arrived to be faulty, it was noticed that there was a swollen capacitor, thus a burnt leg of the chip, the seller will return my money, after a dispute
POWER AMPLIFIER MX50. 2 CHANNELS EACH 100 W.
Two 100 Watt power amplifiers entirely transistorized without using SMD components. Supplied in a self-assembly package. The kit includes PCB and a set of parts. It is extremely rare that a circuit diagram on paper is included - sellers refer to the fact that everything is written on the board. Just in case, below is circuit diagram of this amplifier, which we managed to find:
The power amplifier has two main subgroups, depending on the supplied final stage transistors. One cheaper option uses a pair 2SD1047 - 2SB817 or 2SA1941 - 2SC5198. With a power supply of ±42 V into an 8 Ohm load it is capable of developing 100 W. The second option is equipped with 2SA1295 - 2SC3264. This option is also promised 100 W at 8 Ohms, but if they promise to equip them with ORIGINAL SANKEN, then the collector power of these transistors is 200 W, therefore, with a power supply of ±40 V into a 4 Ohm load, this amplifier can safely deliver 150 W. Of course, this amplifier option is somewhat more expensive. The remaining characteristics of this UMZCH are given below:
Supply voltage: ±15 V to ±45 V
Output Power: 100W8R (±42V)
Voltage gain: 34 times
Input Sensitivity: 1.2V 100W RMS 8 Europe
SNR: more than 98dB
Distortion:< 0.009 THD 1 К ГЦ 10 Вт
Quiescent current 30 mA
Single channel board size: 76mm*73mm
Frankly speaking, so much power is unlikely to be needed for domestic use, but class D power amplifiers deservedly take their place in household appliances, and their simplicity and compactness make it possible to assemble lightweight and powerful audio amplifiers. The use of a specialized IRS2092 microcircuit makes the assembly and configuration of the amplifier quite simple. For those who do not need 2 kW at home, there are much simpler and cheaper options:
How to determine what transformer power is needed for an amplifier is shown in the video:
Once upon a time audio amplifiers(VLF) were large, with a bunch of tubes, huge radiators for transistors, heavy transformers in the power supply. But life does not stand still. Now compact microcircuits with digital ULF have replaced tube and transistor dinosaurs in almost all consumer devices. You can easily design a compact amplifier, for example on the PAM8610 chip. The power supply from the review was used for power supply.
The ULF on the PAM8610 exists in several versions and is quite inexpensive. For example, you can buy it here -. It was decided to use a ready-made board with a volume control and soldered connectors. There is also an ultra-budget option. It was reviewed here on the website -. Why this particular amplifier - price and very good impressions from the younger models PAM8403/PAM8406: , .
Let's see how the older amplifier model performs.
Module characteristics:
Power supply 7-15V, recommended 12V
Power up to 10 W per channel at 8 ohm load resistance
Protection against short circuit, overheating
Amplifier efficiency up to 90%
Judging by the description, excellent characteristics for such a baby.
Photo: 
The flux is a little not completely washed off.
The speaker connections are not indicated in any way. It was found out empirically and using a similar slightly different board: 
Power plug - center "+", around - "-"
The microcircuit under the radiator of this amplifier version is good. Jumpers on the board - one temporarily turns off the sound (mute), the second I don’t know.
To power the structure, it was decided to use the power supply from the link at the beginning of the review. This power supply has been reviewed in great detail. The power supply works well in extreme conditions, is compact and inexpensive. Theoretically, you can get a total power of about 12 watts per two channels with this power supply. Or real about 5 watts per channel. I was satisfied with this power supply and the ULF power. For greater gain of the microcircuit when using a signal source in the form cell phone or the DAC needs to use pre-amplification in front of the microcircuit, which I didn’t want to do. And 5 watts of power per channel is enough for my purposes. But we will still test the ULF and PSU microcircuits in different modes and on loads of different resistances.
Power unit: 
To test the load we use powerful resistors 4 Ohm, 6 Ohm, 8 Ohm per 100 Watt: 
You can buy them here
We connect all modules and resistors. 
We take measurements.
The amplifier supply voltage is 12 V, a 1000 Hz signal from a sound generator is supplied to the input. Power is calculated by the square of the voltage at the output of one channel of the amplifier (measured with an AC voltmeter) with a connected load divided by the load resistance
First group of tests
Normal source (phone or DAC). Uin = 0.15 V. Testing was carried out on the power supply from the review, without preliminary amplification. In all cases, the overheating protection on the microcircuit and the current protection on the power supply did not work. 
I have speakers with a resistance of 4 Ohms - the first line is my mode of using the amplifier.
Second group of tests
Disabling the power supply from the current protection review. We increase Uin until the protection on the power supply is triggered. This mode is possible when using a pre-amplifier (for example,) before the amplifier from the review 
Third group of tests
Limit mode. A laboratory power supply is used. The tests are completed if the amplifier chip turns off due to overheating (the temperature of the chip in this case is more than 100 degrees Celsius). In reality, to implement this mode, you need a more powerful power supply (12 V 2 A for example) and preliminary signal amplification. 
I think more power than stated was achieved using a radiator on a ULF chip.
Tests may be useful if you are going to use this ULF chip for your amplifier or make a powerful one portable speaker with preamplifier and powerful battery.
Chip heatsink temperature. The radiator here is good. But there are versions of this board without a radiator. 
Temperature at resistors: 
If there is such a temperature here at 9 Watts, then what will happen when testing a 100 Watt amplifier?
Sine wave test. We apply a 1000 Hz sinusoid to the input and use an oscilloscope to see what we have at the output of the amplifier.
18+ Readers with unstable mental health should not watch
Amplifier input: 
Output at very low volume: 
Average volume level: 
Sine wave at maximum. The ULF chip is on the verge of shutting down due to overheating. 
I was surprised by the results - the younger PAM8403/PAM8406 output with a sine wave is ok. Maybe I mixed something up when measuring. I went online and found a video review of a similar microcircuit - . True, your friend there did not connect a load to the output and carried out tests without a preamplifier (he did not bring the microcircuit to its maximum modes).
After completing the tests, I decided to refine everything. Components for assembly:
The router is used as a . I asked for it in the same way as the review. A toggle switch was also made for a regular linear input.
The case was purchased offline for 400 rubles - the cheapest in terms of price-size-quality ratio.
It turned out like this:
Initially, a 12->5 V DC converter based on a PWM controller was installed. But I had to install a second 5V power supply for two reasons:
1. Interference. I removed the ground loops, but some interference (possibly from the converter) remained.
2. In case of overload, the power supply is switched off by protection - the router is overloaded and this is not good - it takes a long time to overload.
Result: 
My mini hi-fi system: 
For my tasks (sounding the bathroom and corridor), the power of the power supply and the sound quality from the ULF are quite enough.
The product was provided for writing a review by the store. The review was published in accordance with clause 18 of the Site Rules.
