It kinda hurt when you clipped that 3.5mm's cable so close to the connector.

GreatScott: Doesn't say *Let's get started* Me: WHO ARE YOU AND WHAT DID YOU DO WITH SCOTT?!

First of all thank you for discovering such a problem. I've been suffered with this problem for a long time. Finally you revealed it. It was such a great demonstration with diagnosing & resolving. I think it's a prefect solution for those noises & it's pretty easy to solve it. Keep rocking Scott, stay creative 😉

Oh man you’re a master, you produce videos of all the questions I used to have some years back and never had an answer to

Hey Scott! I used this same technique in my creative desktop speaker pair a year earlier and it works great. Thanks for shedding some light on this matter. Nice job man! 👍

Two notes from somebody who has used these little all-in-one isolated 1W or 2W power supply modules in projects before: -These devices are typically *unregulated* (including the specific one shown here), meaning that especially at very light loads, their output voltage can be substantially above the rated 5V and they will vary dramatically depending on the load current. -The power supplies usually have very high idle power consumption (5-20mA is typical) and also low conversion efficiency at low load. This makes them quite unsuitable for battery powered applications unless you can shut the converter off completely during idle times and your active circuit power is well above the idle consumption of the converter. Check the datasheets carefully before specifying one of these in a design - most of the graphs sneakily only show efficiency/regulation starting from 10%-20% of rated load, and their behaviour is *much* worse below those points! For light loads, this can be a big issue.

Thank you so much for making this video I was facing the same problem when I hooked up the receiver to my cars basic music system. Now I will be able to smack down the interference noises. Keep it up👍👌

this video gave me the solution , that i was looking for over an year .. i am not an electrical expert , but i also did build my own music system and faced this problem .. and after a year later .. now.. i found the solution here THANKS

I powered my Samsung 10" tablet that I integrated in to my car by wiring directly to the car's cigarette lighter power feed, however, this created this same ground loop effect. I overcame that by buying a hefty 12v > 5v DC/DC isolating converter, but it was quite expensive, as I wanted it to be quite a high Amp rating in order to charge the tablet whilst using it. Great video!!

Excellent solution. You can also measure the voltage between the 5V negative rail of the receiver and the 3.5mm ground, when thereceiver is powered on. In my case (slight different receiver board) I measured a 3.3V difference between the 2 "grounds", that definitely means the receiver need a galvanic 5V separate source.

I built a mic and amp circuit from a salvaged electret mic from a cheap headset and a LM386 as an amp. 3 volt coin cell for the mic and 9v batt for the amp, with gain and volume controls. Whenever I turned the gain or vol up, terrible hum, like a horn. I could see the oscillation on the scope. Separating the grounds fixed the problem. Now I can use it to hear previously undetectable air leaks. THANK YOU for the solution to the problem !!

I have the same problem, and i really struggled to find a soloution for this. Thank you really much for explaining this problem and showing some soloutions! It kinda saved my day.

As a person with electronics background I really enjoy you videos man. Keep up the good work!

Not to long ago I was looking for this exact solution but no video could resolve my issue, but I'm glad you have made a video about it.

Thank you for going through all the effort of building up every possible solution just to educate us. Have a nice weekend.

@GreatScott! Man i bought the exact same Bluetooth module 2 years ago and never managed to get around this buzzing noise. I can now finally finish building my diy bluetooth speaker, thanks so much❤

I searched the whole internet for this before with no suitable results! Thanks!

Thanks Greatscott, I would need ground isolation for my school's buggy project where there are sensor, motor, and control subsystems involved.

Noise is the bane of audio projects, thanks my dude.

In a project i had the same problem as you and this solution comes to be the best one. Thanks a lot!!!

Two other areas you could look into are: a lower impedance ground between amp and receiver as well as better supply decoupling on the output of the 5v regulator. The decoupling network needs to take into consideration the frequency content of the receiver in order to decouple successfully.

DC to DC isolator is the best of the best solution for diy amplifier projects. It helped me removing the buzz noise!

I often do skip the intro music on channels but not yours. Love that music

I had the same problem. And I tried the same methods and stayed at DC/DC converter, the best method. I really didn't realize what the problem is, if the amplifier and the bluetooth receiver have the same grounding, thanks for the explanation GreatScott xD

So wish l had your knowledge and Time as l'm getting a little old now going for 67 in couple of days. Still l enjoy to see you solve problems for so many , thank you for sharing.

Literal i need this 4 hours ago 😂

I enjoy even the way that Scott writes (left handed).

was just suffering from the same problem. thanks a lott, my friend great scott.

THANK YOU! I've been having this problem while building a DeLorean time machine replica and this should fix it!

Thanks Scott! I was really thinking about this one. Keep it up bro...

Well that's great. Your are my inspiration sir. From your video my interest on eletronics multiplies more and more. Love from india sir.😇🙌

Thank you, it is very informative and helped me solve similar noise problems on my bluetooth connections as well.

Was going to convert an old boom box into a Bluetooth one. Thanks for telling me about this issue I was going to face.

Thank you greatt scott i learn a lot waching all your videos Keep up the good work👍

You know what i find most interesting in this video? Your amplifier. It uses an unbiased output stage where you're simply forcing the opamp to slew right over the required approx 1V bias voltage gap of the output transistors, and to somewhat smooth out the resulting switching atrocity, you have a feed forward resistor. This is actually kinda cool. According to my simulation, not quite hi-fi, but cool.

Thanks for the informative video! You fixed my noisey Bluetooth speaker build!

The 1:1 transformer in between the audio did not work as the two grounds were still connected. If the 1:1 transformer was used two separate the grounds it would work, however, you of course can not do that with DC so you have to use a switching converter. This is precisely what the DCDC converter is; a transformer with switching power supply. I think it would have been good if you would have mentioned this in the video.

Been looking for a solution for this problem. Thanks for making a video.

Brilliant video ! If i only had it a couple of years ago ! had the same problem and ended up using 2 mains supplies.

Most interesting, many thanks, stopped me from chasing red herrings and focus on the simple fact that the noise comes from the power rail. This led me to a simple fix ... Starting with an existing power amp with a single rail 20V supply I used a 7905 to create a ground that is 5V below the positive rail. This creates a split supply to power my op amp based front end. The op amp doesn't care that the rails are asymmetric +5V and -15V. The Bluetooth audio module powered from the +5V rail produced a massive amount of noise but a 5mH inductor (a few windings on a toroid core,

Great vid ! I am work on a batterie power system and i have the same problem. Thank you for the multiple solution and the explanation !

Hi scott thanks for your very informative videos. Can you also cover the use of ferrite rings to reduce EMI from the ground ? And how to use them properly ?

i love those tiny DC to DC modules, they are so freaking handy.

great i was looking for this type of video thankyou man THANK YOU so much and as always amazing video

Great scott: I couldn't find the amp Me: LOOK ON YOUR CEILING

Your video move my heart to use my bluetooth earphone once again, of course after fix it :D

Was waiting for the video; you read my mind !!

Nice solution. Love your work. Keep up the good work.

thanks for this vid,, got a solution for my mini mixer audio project … god bless bro!

I was looking for this for a long time Thanks dude I use 2 different power supply But it seems to much So I'm looking for better solution

3:19 Scott: "So where do they come from?" Me: _No._ My Brain: "Where did they go?! Where did they come from, Cotton-Eyed-Joe!" Me: *NOOOO*

Thanks, I have just recently got some of these BT receivers and want to use them, so this is super helpful. At least for me...

Very informative. This was really well done. Thanks!

The ground loop isolator is used when your amp and source are on separate connections The point of it is to stop one device using the other as a ground. Additionally a ground loop is characterised by a 50 or 60 Hz continuous humm, the fact that it has a repetitive load (likely when the Bluetooth is transmitting it's beacon) shows it is not a ground loop

Great walkthrough 👍❤️ Thanks for sharing 👍😀

The noise sounds like some kind of oscillation, which is pretty different from other ground loop noise, like a 50Hz humm. This may also happen within amplifiers without connection of Bluetooth adapters or the like. Reason is the introduction of additional resistances in the ground path due to the internal resistance of wires and a resulting voltage drop. As mentioned in some other comment, all paths to ground should be as short and thick as possible. Best is to connect everything to a single point and avoid a ground rail design. Connecting a bluetooth module with a common ground strongly violates this design rule and therefore introduces these kind of problems, I assume. Just a guess.

exactly what i was looking for!! thats crazy!! im gonna make a portable diy blueth speaker! thanks!!

This video is super useful for my factory radio bluetooth mod (Added bluetooth to my cars factory head unit).

I needed this video a week ago.

Good topic for proff audio stuff. Ground is always important.

I was looking for this perfect video! and got the solution thanks!

HERE IN NICARAGUA WE CANT DO IT EASY BUT I WILL thanks to the master Greats

You should give your completed schematics in the end of the video or the description, so if we ever want to attempt such a test we can see where exactly the change occured. Btw, YOU ARE AWESOME DUDE. I mean it.

Boi i've been having the same problems, I tried to connect two different amps together to form a bigger amp with a separate line for smaller speakers. And i got a crazy buzzy noise. I just gave up on that project because there was nothing i can do. I will try the DC/DC converter method. I just hope its available here at my local stores. Thanks for making this video mate!

my dad have the same problem and then i remember your video and show it to my dad this was helpfull

i used a dc to dc isolator too when i worked on my diy bluetooth speaker. worked perfectly

Ohh that is EXACTLY what i was looking for. Thank you soo much

Thanks so much Scott! Great video!

Great video man... Helped me to solve the problem I was facing

Thanks so much, I'll try with this DC-DC converter, greetings from Mexico :D

funny that i did this experiment last year when adding BT OVCxxxx module to my car stereo's tape deck preamp output. Isolation transformers were a nogo but i remembered that i had some of those isolated DC-DC converters and it was perfect. I ended up using an ATtiny to monitor the tape deck motor outputs to simulate the encoder signals and give the bt module the ability to skip and prev songs using the OEM controls.

Stay Blessed keep up the good job. Im new to this but i can read it very simple and understand what your saying make sense. If you know or have anything/equipment not in use for a beginner for free/i wish or for not alot of $$$ i know but it doesn't hurt to ask. Thank you very much. New sub here for life. Thank you again.

Great job as always! I was wondering which type of wire do you use for your traces/jumpers when doing your circuits on perf board? I’ve been trying to find something appropriate but am unsure what to get.

wow man... this looks amazing and promosing... i have ground loop problem in my car with BT and phone adapter charger in 12V port

I just love your explanation and ideas and everything ❤️ and that I will see you neeeext tiiiiiiime.....😀

Great video, GreatScott! Love your pen diagrams, but hard to see clearly in frame sometimes - have you uploaded scans or square-on photos anywhere?

Helpful information. I like your video

Your solution with the different power supplies seems to work for my case where I wanted to connect a TDA7498 with a seperate bluettoh module... Thanks!

This is a great video I wish you got around to the gameboy sp pi build have been waiting forever... also wish you would do a designing circuits video series like your basics. I hope this doesn't come off wrong love your videos bro I just am a little intoxicated

Add some bypass capacitors across R1,R2 to to decouple your amplifier's virtual ground (pin3) from supply fluctuations. If you use the isolation transformers then you can connect your input signal ground to this point as well.

A lot of that noise can be removed by adding extra capacitance to the power supply rails for the bluetooth device, along with making it the common ground point for the project, so that the long cables to the input are not adding resistance to the ground path. 220uF 10V capacitor directly across the 5V pins into the unit will improve performance a lot, as the regulator output impedance rises with frequency, they are not good at reducing high frequency noise, you need low ESR capacitors near the load to do that.

Always waited for this video

that's exactly what's pissing me off the last week. thanks!

I was just making this as part of a college project and stumbled upon the same problem. Thanks a lot Great Scott, it's like you read my mind.

OMG I have this same model that I bought from eBay 3 years ago for a project ... And never used it .. time to check

Thanks a million! Much appreciated.

You Really Saved My Day

I'm soo glad to have watched this

Exactly what i wanted to search.

Greatscott: let‘s find out in this video! Me: huh ? Who are you

This guy and diy perks complete each other

Thanks i literally need a solution !!!!😁😁👍

Sir, very nice video,, it's full of information.. Thank you so much,.. I have a question sir. I have the same bluetooth that you shown on your video thumpnil. When I played a song the bluetooth receiver giving cutting sound? What should I do?

this problem bust my ass for 7 years on every project and even electronic teachers tell me use two battery on adaptors thank you manso so much

Pretty interesting, dude! Thanks a lot! 😃

thanks for the guide line

Great video as always

Usually i just solved this by disconnecting the audio ground. Quick and dirty but it worked.

Deep and clear info

You solved one of the reason's for the annoying white noise mate... 🍻