Cheap Bluetooth audio receivers explained: pros, cons, how to use

[@srpatnaik4548]

Genuine Advice...Greetings from India.

[@daffodilistic]

1:19 The "Bruh" brand PCB 😂

[@Loujemouse]

Great video! I was thinking of upgrading my old speakers so they would work with bluetooth

[@aromalm.s8105]

I've used one of these, the stereo quality is good considering the price. But the low frequency is where I felt the difference in terms of audio quality between wired and wireless

[@mackyfeolino737]

what is the connection diagram to use that isolating transformer.?

[@krtk9675]

How is the quality for earphones or headphones?

[@devicemodder]

I have an aliexpress MP4 player that has composite output. The audio is noisy (i can hear SD card access) this happens regardless of if the player has a seperate supply. I need to eliminate this, as I have stuck it inside a CRT TV.

[@simphiwelehlohonolo4961]

Informative video 👏 thanks

[@threeMetreJim]

I bought a couple of these, with a built in amplifier some time ago. Unfortunately they have a horrible (and embarrassing) Chinese voice that plays at full volume that can't be easily disabled (the dev kit for the chip has viruses). Ones without buttons (the ones I have) have an input on the chip that will work for this using something called AD-KEYS (one pin has a pull down resistor for an apparent non-use). It's one pin used to detect button presses by changing the resistance presented to an A to D port (I guess that's whjy the name has AD)

[@309electronics5]

Unfortunatly there is no way of turning of the voice. Its included by default in the sdk and usually manufacturers dont change much and just compile in the default template because it saves money and they wont need to hire programming people. Also the sdk is not really fully documented well. Some boards that dont have usb sound card functionality can still have it implemented in the firmware and board layout (becauss again manufacturers are lazy to desugn their own thing and use premade schematics) but they just dont place a resistor or jumper disconnecting the usb data lines but leaving pads that can be bridged. I had some models like that. Also if you do plan on tinkering with the firmware, they can be programmed using usb in DFU mode. You have to put a specific signal across the usb pins to put it into dfu mode. The Dfu mode is burned into the bootrom of the ic so you wont erase the functionality. The chips also use UBOOT as their bootloader. They use JieLi's sdk to compile and flash the code onto the flash

[@LeftyMaker]

Very useful info!

[@threeMetreJim]

I have the older sdk used for the older JL chips, unfortunately it is very hard (if not impossible) to find now and contains viruses, so I never used it. The JL AC46 BT SDK version 1.2.1 - It has the annoying voice mp3 files included...

[@vipulbhardwaj1537]

I have red one and its connection sound is like black one. But there is one issue, whenever I play audio it transmits a hiss along with audio even when volume is zero. One way to avoid it is a RC filter at output but that reduces the high frequency performance.

[@parsipax6337]

get the m18, it has key pinout for controls 😊

[@PrinjPal]

Lady voice ?

[@DrFailov]

Good video and useful information

[@suttle_writeups]

Would it be good for making diy headphone with bluetooth

[@LeftyMaker]

yes, I suppose it would work

[@vishnuvardhan6384]

is there is any way to amplify the sound to 3.5mm because I'm using the kcx bt002 module that provide the sound with no actual base or anything just a mono audio with lowest sound..

[@LeftyMaker]

I believe you have it connected wrong. There are three analog audio outputs: left, right, and ground. You connect your left channel to left and ground, and the right channel to right and ground. Right now it sounds like you have one channel connected to the left and right outputs, so they cancel each other out and you only hear the difference between the channels, which explains the lack of bass

[@shadowhunterxxx5891]

There is many bluetooth module with amplifier that used common power supply without any noise but when used tow seprated module with LC filter and short wires still there is ground loop noise

[@LeftyMaker]

Yes, I have come across good ones, but all I've tested with a JieLi Bluetooth chip have had beeping noises. The better the speakers, the more you can hear them. CSR BT modules are much less noisy and have never had lady voices too

[@velixo3338]

Hey, weird question ik, but do work as an engineer?

[@LeftyMaker]

No. That's just a hobby

[@hippohoppa]

If I attach a rechargeable battery to it, can it get charged through the micro USB?3

[@LeftyMaker]

No. You may even damage the battery by doing that

[@hippohoppa]

@@LeftyMaker Ohh so you can't solder a lithium battery to it! Thanks for letting me know

[@ArkarPhoneKyaw]

You can use a charger module and connect the battery there

[@hippohoppa]

@@ArkarPhoneKyaw Great Idea! Will need an extra box to attach everything inside tho Thanks!

[@hasnatjamil8821]

should i add lithium ion battery directly or should i add a protection circuit in the middle like tp4506

[@myshticaanimo2169]

Can't find these JL ic data sheet 😭

[@LeftyMaker]

search JieLi on LCSC.com and one/some of the chips there are probably on these boards

[@myshticaanimo2169]

@@LeftyMaker I will try Thank you😇 it work I was trying to find this manufacturer from long time

[@309electronics5]

These ics dont really have any great documentation and it requires some digging. Also the number on the ics dont match with any datasheets and are likely firmware revisions and id number of the mfr. Most are from the JL ac69xxxx family

[@myshticaanimo2169]

@@309electronics5 thanks❤️😇 But somehow almost every Bluetooth ICs are from them

[@mykflyst]

💯

[@VandalIO]

You had the Bluetooth transmitter in the floor ! You should have tested the range when the transmitter was atlas 1.5 meters off the floor

[@LeftyMaker]

is the floor lava or something?

[@VandalIO]

@@LeftyMaker 🤦‍♀️

[@VandalIO]

@@LeftyMaker comment was meant as constructive feedback ! It’s radio transmission 101, transmitters ideally need to be above ground or sea level to reduce *multi-path interference* and reduce *fresnel zone interference* having them higher than ground could have produced more meaningful result in real world scenarios