MPOW Streambot Box sells well in Chinese online stores and has quite good reviews there. And given the support for the A2DP profile and AAC/aptX ® codecs, it fits my needs perfectly. I won’t go into details regarding codecs and profiles, but this is some good introductory material on this topic.

Equipment and appearance

Srteambot is supplied in a small box made of thick cardboard. The kit includes only a 2 x Mini-Jack 3.5 mm cable, an RCA-Mini-Jack 3.5 mm adapter and a USB-microUSB power cable.

The standard delivery package requires a high-quality power supply, because... If the speaker does not have a USB output, you will have to buy a separate power source. Connecting to cheap power supplies is fraught with noticeable hum and other interference in the sound of the final system.

Similar properties manifested themselves when I connected the receiver to one with built-in USB ports, but no such problems arose when connecting.

Connecting a BT receiver takes just seconds. After power is applied, pressing a single key will make the device visible on the network. All that remains is to select “StreamBot Box” in the corresponding menu on the client device.

That's it, the receiver is ready for use. You can connect 2 clients to it at the same time; to do this, turn off Bluetooth on the first client and repeat the pairing procedure with the second.

As for sound, everything is not so clear. My laptop supports the aptX ® codec, so I don’t hear a noticeable difference in sound on the Microlab Pro 2, much less the Logitech X-240. But an Android smartphone cannot boast of such functionality, and a decrease in bitrate is felt on both speakers. The sound at volumes above average would be called “mushy”; there is also a lack of high frequencies.

With a short period of inactivity (10-15 minutes at a glance), MPOW Streambot turns off and, accordingly, terminates existing connections. For further playback, you need to activate the receiver by pressing a button. This approach is absolutely unacceptable for a stationary device, so for my purposes I had to abandon the use of Streambot Box.

And finally - the range of action. If everything is fine within one room, then when you go with the phone to the kitchen or balcony, which are located behind a load-bearing wall, the connection is often interrupted.

What is inside?

The device is disassembled by unscrewing four screws under the rubber feet on the bottom of the device. Inside we find a tiny circuit board and a piece of metal that explains the weight of this device.

The heart of Streambot is the popular module based on the CSR8645 chip. The price of such boards on Aliexpress varies per piece. Why popular? Because it's cheap and widely used wireless speakers, headphones and headsets made in China.

To amplify the power of the sound signal, a separate microcircuit is used -.

What I liked

• Easy to connect and use
• No delay during playback

What I didn't like

• Auto shutdown when inactive
• Radius of action

Wi-Fi audio receiver AIRTRY

Price:

I found AirTry after purchasing the BT receiver in the catalog of the Era-in-ear online store and bought it out of curiosity. This device allows you to broadcast audio via Wi-Fi using the Apple AirPlay and DLNA/UPnP protocols. It is also notable for the fact that it is manufactured in Korea, as evidenced by the inscriptions both on the box and on the device itself.

Equipment and appearance

The standard delivery set includes: 2 audio cables (2 x Mini-Jack 3.5 mm, Mini-Jack 3.5 mm - RCA), power supply with USB output (5 V, 0.7 A), cable for connecting to the power supply and illustrated instructions in English language.
The device itself is sealed in a white plastic case, the upper part of which is glossy, and the lower part is made of ordinary rough plastic. All connectors are concentrated on one edge: audio input, output and microUSB for power. Two mini-jack connectors provide pass-through connection of the device.
Unlike MPOW SreamBot, this device does not have any weights and weighs only 40 grams, and its soft, non-rubberized legs “contribute” to the movement of the box even with light contact with the wire.

Connection, configuration and operation

AirTry Music Receiver can act as a client in Wi-Fi networks or a full-fledged access point in the 2.4 GHz band (g/n). The last mode, judging by the instructions, is intended for use in a car. After power is applied, the receiver creates an open access point called Airtry_MP_AP. We connect to it and go to the address 10.10.10.254 to the settings page.
After connecting to home Wi-Fi network, the device will reboot, blink the indicator LED that I forgot to mention in the previous section, and will be ready for use as soon as the LED stops blinking (after 30 seconds).

The receiver is immediately detected in iTunes, and the laptop connects to it without any problems. Unfortunately, the very first tests indicated that this device was unsuitable for use in my home theater setup due to the large delay during playback. For music, 2-3 seconds do not play any role.

After updating the firmware to version 1.2.0 and re-configuring, audio and video desynchronization seems to have become less frequent, but the 1-2 second delay from pressing the Play button to the start of playback still remains, and in everyday use this behavior is somewhat annoying. Latest version The firmware can always be found, it is installed through the receiver’s admin panel, which can only be accessed after a reset.

On Mac OS, AirTry can be set as the default output device. There are no problems with iOS either.

The operating range depends on the Wi-Fi coverage area in your apartment. It easily copes with a one-room apartment in a panel house, so the receiver works both in the kitchen and on the balcony. As for the sound quality, I didn’t notice any difference between a wired connection and audio transmission via Wi-Fi.

What is inside?

AirTry is as easy to disassemble as Streambot. There are screws under the two legs on the bottom that need to be removed. Next, use a pick to unclip all the latches and the case is disassembled.

The power amplifier integrated into the DAC is significantly inferior to the discrete solution in the reviewed BT receiver. So, in the Streambot Box, with a load resistance of 16 Ohms, it “produces” 132 mW, while the DAC from Wolfson, with a similar resistance, is capable of only 18 mW.

What I liked

• Pass-through capability
• System expandability
• Sound quality

What I didn't like

• Playback delay
• Limitation when working with Android

Bonus: First generation Apple TV

Cost: 325 hryvnia / 13 dollars

On a weekday, when leaving the grocery store, I noticed a fairly impressive size “Second Hand” store. I don't hesitate to buy clothes in such places, because... you can find very good things there for the right price, so I stopped by on occasion. At the entrance there were two baskets about two meters long with various used equipment and among them, to my surprise, was. This hefty box, more reminiscent of a modern Mac Mini, was released in 2007 (9 years ago!) and is based on a single-core Intel processor Pentium x86 architecture.

Unfortunately, I got the Apple TV without a remote control, and to this day I haven’t bothered to buy a new one, but by connecting the media player via an Ethernet cable to home network, iTunes recognized it without any problems and the music could be streamed. The delay feels less than with the AirTry, but is still annoying.

It is worth noting here that the first Apple generation TV has a full optical output along with the usual analogue one, so for good acoustics this option would be even preferable.

In general, for $13, this box is a treasure trove of quality components. Consider an excellent 36-watt power supply (5 V, 7.2 A), a Wi-Fi mini-PCI card with support for b/g/n standards and two antennas, and a 40 GB IDE HDD. Despite the outdated technical characteristics of the media player, adding a modern hardware decoder instead of a Wi-Fi module and replacing the old HDD with flash memory.

Advantages

• System expandability
• Minimum playback delay
• Sound quality, optical output

Flaws

• Power consumption (~20 W)
• Inability to install system device output

Results

The transformation was successful; AirTry was introduced into the current setup in end-to-end mode, which is used to play music from various mobile devices. To play video as part of a recreation center, a wired connection is still used.

For convenient switching, I used a switch that I picked up from the official FiiO representative office in 2014. In theory, it was intended to compare sound sources, but in reality it serves as a switch for speaker systems. :)

All this is a temporary solution, since I still want to get rid of the wires. I'm currently looking at the 3rd generation Apple TV. True, I’m not going to stop using a MacBook, but it’s not clear what to do with Android smartphones, which I would also like to integrate into my home system. Maybe get one?

Related links

. On my website I duplicate my own publications from all over the Internet, so too. Thank you for your attention!

The other day we received XS-3868 Ver.3.0 Bluetooth audio modules based on OVC3860 from the GearBest online store. The modules are a device to which you can connect via Bluetooth and transmit an audio stream over the air. The cost is approximately 3.5 dollars. The small size and power supply of the module, fully adapted for operation from 3.7 volt Li-Ion batteries, allow, in my opinion, to integrate these modules into great amount of their devices: these are homemade Bluetooth headsets, wireless and portable speakers, And wireless interface for speakers and players, and some kind of intercom devices (if, of course, the operating range is satisfactory), and everything else that the imagination of a radio amateur can reproduce.

Specifications Bluetooth audio module XS-3868 based on OVC3860:

• Frequency 2.402 ~ 2.480 GHz
• Transmitter power 4 dBm (PCB antenna), Class2
• Receiver sensitivity -82 dBm
• Module size 30 x 17 x 3.4 mm
• Bluetooth: Version 2.0
• Range approx. 10 m
• Data transfer speed up to 3 Mbit
• Possibility of connecting an external antenna via an SMT pad
• Possibility to connect a mono microphone
• Controlling audio flow and volume level (buttons)
• Indication of module operation by two LEDs
• Stereo audio output (designed for connecting headphones with speaker impedance of 32 Ohms - built-in headphone amplifier with a power of 40 mW)
• Supply voltage 3.6 – 4.2 Volts
• Current consumption up to 55 mA in audio playback mode
• Current consumption in sleep mode is less than 10 mA (actually less than 1 mA)
• Transition time to power saving mode 5 minutes (if nothing is playing)
• Profiles: A2DP V1.2–Sink Only, AVRCP V1.4–Controller Only, HSP V1.2, HFP V1.5
• UART connection speed 115200 baud (mainly used for debug)
• Built-in 20-bit stereo DAC
• Built-in 16-bit mono ADC
• Built-in battery charge controller Li-ion, Li-Pol, charging current up to 150 mA
• Connection password 0000

Module characteristics are copied Bluetooth specifications OVC3860 controller.

The module has the following pinout:

Purpose of module pins:

• 16, 17, 19 – stereo audio output (for headphones, not every audio system will support it, so when connecting to some speaker systems you will have to add a preamplifier, unlike headphones, the 5.1 microlab system refused to work normally with this module when connected directly)
• 22, 23 – contacts for connecting a microphone (Bluetooth headset after all)
• 24, 26 – contacts for connecting LEDs
• 25 – 5 volt power input for charging the battery
• 31 – earth
• 29 – battery plus
• 33 – output 1.8 volts
• 35 – contact reset reset
• 36, 37 – contacts of volume control buttons
• 43, 44 – UART interface
• 52, 54, 55 – contacts of audio flow control buttons

To start using a Bluetooth device, you do not need to do any complicated actions, you just need to connect the power (battery), a 4.7 kOhm - 10 kOhm resistor between the 1.8v out and rst pins and a headphone jack. By default, the module is visible to other Bluetooth devices as POR 1007BT. We connect and enter the password when prompted. The module is defined as a headset, and when connected, the sound will be transmitted “over the air”. If you connect only power and headphones without module buttons, the volume will automatically be at maximum. It all depends on the device to which the module is connected. So, when adjusting the sound level on the tablet, the sound is also adjusted on this Bluetooth module, and when connecting to a phone ( Philips xenium x130) the volume level simply remains at maximum or simply turns off as you do not adjust the volume of the audio file playback.

Here simplest scheme module activation:

By using a few more pins of the Bluetooth module, you can make a slightly more functional device with buttons and LED operation indication, diagram:

And then simply by adding a microphone, connecting it to the corresponding pins of the Bluetooth module, using the appropriate microphone connection circuit, you can use the device as a full-fledged one Bluetooth headset for talking on the phone, for example. By the way, you can estimate the dimensions of the parts and see that the device is no larger in size than many factory copies.

Although the module has the ability to charge a small-capacity battery, using this function here is not very beneficial: 1) nothing is played in charging mode, 2) the charging current is small, which means only small batteries can be used, 3) switching to sound playback mode after charging requires additional action - either disconnect and connect the headphones, or press the reset button, which you will have to do, or simply turn off the power. In my opinion, it would be better to additionally use charging circuit for a battery, for example, based on TP4056:

The dimensions of such ready-made modules are small and they are smaller than the batteries themselves, even of small capacity. Therefore, I think that this is a slightly better option than the built-in Bluetooth function of the module.

If you use such a module, then two nuances must be observed: 1) you cannot turn on the charging module connected to the Bluetooth module without a battery, since the voltage at the output of the charging module without a battery can exceed 4.2 volts; 2) set the charging current for the battery being used. The charging current is regulated by a resistor connected to the second pin of the TP4056 chip. By default, a 1.2 kOhm resistor is usually installed on charging modules, which corresponds to 1 A of charging current. 1.5 kOhm – 780 mA, 3 kOhm – 400 mA, 10 kOhm – 120 mA, 20 kOhm – 70 mA.

If you do not want to use the Bluetooth module as a portable device with a battery, then instead of a battery you need to make a 3.7 - 4.2 volt power supply, add capacitors to the power nodes in the circuit and use it as a stationary device.

Thus, for a small cost you can get a DIY (do it yourself) kit for wireless transmission sound via Bluetooth.

Below you can download some documentation on the Bluetooth module. I hope this short review will be useful in finding solutions for amateur radio purposes.

Progress is certainly a useful phenomenon. But, unfortunately, it has side effects. In particular, we have to come to terms with the fact that now the obsolescence of many electronic devices occurs much faster than their natural physical wear and tear. Take, for example, the music centers or complexes of stationary sound-reproducing equipment that many people have at home. Such devices can faithfully serve their owner for ten years or more. However, the rapid growth of the mobile device segment, combined with the rapid development of online services, has led to the fact that audio equipment that is still fully operational and not very old is gradually becoming less and less in demand.

Will this music last forever?

The reality is that physical media with music recordings are gradually falling out of use. And even at home, many people prefer to play sound recordings via mobile devices. At least for reasons of convenience: now it is possible to play your favorite music from online streaming services and social networks. Plus a wide selection of Internet radio stations, the number of which has long exceeded tens of thousands. And the most advanced users, in addition to this, have extensive personal music libraries on their home NAS drives.

Naturally, in such a situation, the most convenient option for delivering a digital signal from the source to the sound-reproducing device is a wireless connection. Firstly, you don’t have to look for the right cable every time. Secondly, you can move freely around the house without losing connection and the ability to control playback.

Now let's look at a fairly typical situation. There is no longer a new, but still fully functional music center (as an option - a set of block audio equipment), the sound of which you are completely satisfied with. However, due to the reasons stated in the previous paragraph, using this equipment with mobile devices is not very convenient. What to do?

Manufacturers of gadgets and accessories are ready to offer their solutions to this problem. One of them is to connect an external wireless adapter to your existing audio equipment. He accepts digital signal, broadcast from a mobile device via wireless channel, converts it to analog and, in this form, supplies it to the linear input of a music center or amplifier. Such an upgrade will allow you to extend the active life of high-quality audio equipment, providing the ability to connect PCs and mobile devices to it as quickly and easily as possible.

To test the performance of such a solution in practice, we decided to test one of these adapters produced by the famous Swiss company Logitech. The model is called simply: Bluetooth Audio Adapter (literally, “Bluetooth audio adapter”).

Acquaintance

The Logitech Bluetooth Audio Adapter device comes in a small cardboard box, decorated in the traditional white and green color scheme of this manufacturer. An interesting detail: instead of the usual cardboard or plastic eyelet, there is a loop of black cord on top.

In addition to the adapter itself, the package includes: an audio cable 1.5 m long (2 RCA - 3.5 mm mini-jack), a power supply, a quick user guide and a leaflet with warranty information. All this is neatly laid out in the cells of a tray made of thin transparent plastic.

The compact (only 50x50x23 mm) body of the device is made of plastic. Without delving into the description of the design (everything can be seen in the photographs above), we will describe it in one word - “minimalistic”. The design uses a combination of two colors: black and bright blue.

The rear panel contains two RCA sockets, one 3.5 mm mini-jack, and a coaxial connector for connecting the power supply.

A wide rubber pad is attached to the bottom plane for better contact with a supporting surface. There is a light indicator installed on the side, equipped with a matte diffuser.

In the center of the top panel there is a shallow niche in which there is a button to activate the wireless connection mode, marked with the Bluetooth logo.

Connection

The procedure for connecting the Logitech Bluetooth Audio Adapter will not cause any difficulties even for non-specialists. First you need to connect the cable from the standard power supply to the connector on the rear panel. The next step is to connect the adapter to the device to which you plan to broadcast sound. Thanks to the presence of outputs with two types of connectors (mini-jack and RCA), maximum compatibility is ensured. For example, multimedia speaker systems equipped with a built-in cable can be connected directly to the mini-jack socket. In other cases, the connecting cable included in the package will help out. Depending on the type of connectors installed on the connected device, it can be connected to one side or the other.

With the Logitech Bluetooth Audio Adapter, you can broadcast line-level audio to the most different devices equipped with an analog input - active speakers, stereo systems, receivers, amplifiers, etc.

The Logitech Bluetooth Audio Adapter connects to audio sources via a built-in Bluetooth 3.0 adapter that supports A2DP (Advanced Audio Distribution Profile), which provides two-channel (stereo) audio.

When you turn on the power, the Logitech Bluetooth Audio Adapter automatically enters wireless connection mode, indicated by a flashing blue light. To establish a connection, you must enable the search for Bluetooth devices in the settings of your mobile device. After displaying the list of found devices, all that remains is to select Logitech BT Adapter.

If the device you are using supports the A2DP profile, then after a short time a wireless connection will be established (in the examples given, a tablet with Android OS was used).

If you later need to connect a new device to the Logitech Bluetooth Audio Adapter, you can manually activate the wireless connection mode by pressing the button in the center of the top panel.

In progress

So, the equipment is connected, and now you can try out the Logitech Bluetooth Audio Adapter in action. After starting playback of the recording on the tablet, we heard sound from the speakers to which the Logitech Bluetooth Audio Adapter was connected. It is very convenient that the signal can be played from different applications - media player, web browser, games, etc. This allows you to listen through an external speaker system or music center to programs from Internet radio stations, recordings from streaming services (for example, Yandex. Music), etc. The sound volume is adjusted not only on the end device, but also on the tablet. The latter option is more convenient, but does not provide high accuracy due to the small number of intermediate positions.

One of the features of the Logitech Bluetooth Audio Adapter is the ability to establish a wireless connection with two devices simultaneously (for example, a tablet and a smartphone). To switch the source, simply pause the audio playback on one device and then start it on another.

During our tests, we connected the Logitech Bluetooth Audio Adapter to an inexpensive active speaker, a stereo system, and a set of block Hi-Fi equipment. In all cases, the adapter did its job perfectly, ensuring uninterrupted and high-quality sound reproduction. The wireless connection works reliably within a medium-sized room (18-20 m2) and even in adjacent rooms (through a concrete wall).

Conclusion

As we have seen from our own experience, the Logitech Bluetooth Audio Adapter is a truly convenient and extremely easy-to-use device that can serve as a link between modern gadgets and sound-reproducing equipment of different classes - including active multimedia speakers, stereo systems, receivers and amplifiers.

The main advantages of the Logitech Bluetooth Audio Adapter are high sound quality, ease of connection and the ability to communicate with two devices at the same time. It is also worth paying attention to the small dimensions and excellent appearance. I would like to say special thanks to the developers for a very delicate light indicator that does not hurt the eyes.

The disadvantages of the Logitech Bluetooth Audio Adapter model include the non-standard connector for connecting the power source, which is why the adapter can only work with the unit included in the package. It is quite strange that the developers did not opt ​​for the more universal microUSB - after all, in this case, the Logitech Bluetooth Audio Adapter could be used in mobile conditions, connecting to the output of a portable battery.

To summarize, we can state that the Logitech Bluetooth Audio Adapter is an excellent option that allows you to complement the capabilities of your existing audio equipment with the function wireless connection to PC and mobile devices. Such an upgrade will cost much less than purchasing a new music center (and even more so an amplifier or receiver) with a built-in Bluetooth adapter, and will allow you to seamlessly integrate still fully functional audio equipment into the ecosystem of modern gadgets.

MP3862BT - Built-in Bluetooth module for an amplifier, active speakers or radio with hands free mode buy in Master Kit. Driver, programs, diagram, reviews, instructions, do it yourself, DIY

From us you can buy Master Kit MP3862BT - Built-in Bluetooth module for an amplifier, active speakers or radio with hands free mode: price, photo, DIY, do-it-yourself, technical specifications and equipment, reviews, review, instructions, driver, programs, diagram

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MP3862BT
Built-in Bluetooth module for an amplifier, active speakers or radio with hands free mode

Give a second life to your old radio or active speaker.

Are available

Buy in bulk

Allows you to wirelessly receive and play audio files in mp3, wma, ogg, etc. formats. from a phone or smartphones and PC using Bluetooth technology.

The device has a hands free function. Thanks to this feature, the connected amplifier can be used as a wireless headset. Using this module, you can upgrade your old audio system or radio to a modern level. After this modification, it will serve you for many years. The board has controls for volume compensation. The module does not require the use of a preamplifier. The module is built on the XS-3868 chip.

Specifications

Contents of delivery

• Complete module - 1 pc.
• Instructions - 1 pc.

Preparation for use

• Connect headphones or amplifier input to the module output.
• Apply 12V power, observing polarity.
• Turn on your phone and add new bluetooth device"POR 1007BT".
• Play some music. Using the tuning elements, set the required maximum volume level and balance.
• Check completed, enjoy your use.

terms of Use

• Temperature - -15C...+50C pcs.
• Relative humidity - up to 95% without condensation pcs.

Precautionary measures

• Do not exceed the maximum permissible supply voltage of the module.
• Failure to comply with this requirement will result in device failure.

Questions and answers

• Hello! Will this module remember the paired device when the power is turned off, so that when turned on it does not require re-pairing?
  • Alexander, this module remembers the paired device; re-pairing is not required.
• Good afternoon. Please tell me, maybe you are making remote control buttons for this module? maybe you can suggest some option? I need buttons for a car; a possible option is to glue the buttons to a flat surface with third-party tape. I will thank you in advance.
  • Sergey, we do not supply buttons separately. Check them out in the assortment of our partner electronshik.ru
• Good afternoon, why can’t I purchase this product on your website?
  • We add the hands free function to the device. We expect finished products to arrive at the warehouse by mid-summer.
• Will there be an improved model of this device? For example, I'm interested in support for new codecs. Now new processors have already appeared and almost every smartphone supports them, but the module is still selling the old port. Will there be a full-fledged linear output? For example, I really need it, since the volume of the module is much lower than the fm receiver in the car radio.
  • We expect this module to appear by mid-summer. The module will support all known codecs and will support hands free mode.

Review of an interesting and compact amplifier with Bluetooth on board, a wide power range and good characteristics.

Packaging and delivery.

Order processing lasted 2 days, delivery another 13 days.
The track was issued, full tracking, from dispatch to my post office.
The impression of the store and delivery is good.

I picked up a typical Chinese black light package from the post office; it didn’t inspire much confidence since it was quite thin.

Having opened the package, I saw the amplifier in antistatic and 4 layers of foam, quite enough to protect small elements from damage during transportation. But if the post office tries, it might break it.

Review

<Фото в большом разрешении, советую кликнуть и рассмотреть поближе интересующие элементы.>

Back view

There is nothing remarkable here, except perhaps holes for heat removal from the chip to the bottom printed circuit board where is the big landfill.

Chicane

There is flux snot on the contacts, it does not affect the operation, but it is clear that the board was not washed after soldering the connector.

Board Dimensions

The board is 5cm wide

Length 8cm

And 1cm thick

Ts 50x80x10mm

18650 for comparison

Type of connectors

The connectors for connecting the speakers are very convenient, their design is made so that they do not squeeze out the wires (unlike cheap terminal blocks). The size is sufficient to connect fairly thick and tinned wires.

Power connector

The power connector is universal or made with a good margin. Almost all modern laptop plugs fit into it.

The board can be powered from 8 to 25 volts, nominally 20 volts.
When powered by 3x 18650, no problems were noticed, either with fully charged or with discharged ones, up to 2.9V each.

At the power input there is a diode against over-reversal. If you place the amplifier in finished device then the diode can be removed to avoid a voltage drop (about 0.3V).
There is no capacitor on the power line, just as there is no place to put it, I assume that the power supply for this module is meant to be from batteries, where this same capacitor is not needed.

Bluetooth module and pre amplifier

The pre-amplifier is made on the N5532 chip
I can’t say anything interesting about it, it’s an ordinary low-noise two-channel operational amplifier.

Thanks to the large power supply range, you can connect a wide range of power sources to the device, ranging from 18650 batteries (3 pcs in series) to power supplies for laptops.

The manufacturer promises 90% efficiency (which, with an output power of 50 watts, gives 5 watts of heat.)
Recommended characteristics - 2 channels of 25 watts with a speaker impedance of 8 ohms and a power supply of 20 volts.

A small clipping from the datasheet

The microcircuit is designed to work in TVs and monitors, but nothing prevents you from using it for your own purposes - to work with a Bluetooth module.

Although the chip has a fairly large output power, it does not require active cooling; all heat goes through the substrate and is distributed throughout the board.
Even under intense loads, there is no significant heating of the board and microcircuit.

You can also see a double switch on the board; all it does is change the signal amplification mode. But I don’t see the point in it, because if you switch any of the switches to ON, noise will appear (interference from bluetooth).

The store page has an excellent description of the amplifier's controls and connections.
The purpose of the buttons is duplicated on silkscreen printing.

Compound

Establishing a connection with Windows 10 On PC

I have Asus laptop rog gl552vw, but the onboard module is from Intel with wifi and bluetooth 4.0

To connect the amplifier you need to go to the bluetooth parameters (click on the cloud in the panel below
then right-click on the bluetooth icon and select “go to settings”

A list of available Bluetooth devices will open.
We select our amplifier; it is highlighted by an icon in the form of headphones.

Click connect and wait for the connection.

After connection, 2 new devices will appear in the volume control panel.
The sound will be terrible.

As the default device, “headphone” is selected, click on “headphones” and click on the “default” button at the very bottom of the window. Now the sound will be of normal quality.

A little information

The headphone has a low-quality audio format and is intended only for conversations.

The headphone mode has acceptable quality for music.

About the Bluetooth device

Connecting to Android

Turn on Bluetooth, go to its settings, find our amplifier in the devices section, click on it, wait for pairing.

After pairing, you can turn the wireless headset and wireless media stream receiver on and off.

When adjusting the volume, the smartphone speaker adjustment slider changes to the Bluetooth device volume adjustment slider.

Tests
Foreshadowing questions about the video - there won’t be one; assessing sound quality using a smartphone’s microphone is, of course, stupid.

Sound quality is a solid 4. Bass cuts only at the highest volume
High frequencies are not reduced.

I also have a MASTERKIT BM2039 at home on a TD8560Q chip (I bought it a long time ago before the crisis for 150 rubles), it produces a little more bass and plays cleaner at high volume, but at the same time it heats up MUCH more and has only 12V power.

Conclusion

The impression of the product is purely positive, the problem with power supply is very easily solved by purchasing a regular power supply for laptops, standard block The 19V 4.7A power supply will not even heat up during operation.
Good characteristics allow you to listen to music at an acceptable volume without loss of quality.
The wireless connection turned out to be very convenient, no more wires are needed, connect your smartphone, turn on the music and continue using your smartphone.
If you use it at home, you can connect 2 devices at once - a PC and a smartphone, the Bluetooth module will look where the sound comes from and play it, without manually switching the signal source.
Also, when used in a car, you can install a microphone and get a Hands free headset.
The only thing that spoils the impression is the very quiet noise from the Bluetooth module.

pros
-Wireless connection
-Large reception radius
-Wide range of supply voltages
-Compact sizes
-Quality execution
-Easy to use
-Low price

Minuses
-Small interference and noise in the speakers
-Wheezing at very high volumes
-No plastic stands as in the photo in the store

There is also the same amplifier but with an additional line output for connecting headphones or another amplifier, the price is even slightly lower.