วีดีโอ

but my bluetooth is battery powered and still makes this kind of hissing sound

I have a similar issue, i am trying to attach one of those tiny rehargeable blue tooth 5.0 modules with the 1/8" jack to my metal detector so i dont have a wired headset. It doesn't seem to like it. Upon taking it apart, the 1/4" jack on metal detector has what appears to be a bridged mono, there is a soldered jumper between the R and L on the jack. And it has a 3rd wire with a internal tab that must disconnect the onboard loud speaker on the detector. I plugged the BT transmitter in and linked it to my BT head set and I get a weak like only a quarter power sound. When i first turn on the detector it gives a loud beep and a drone sound to signal it being powered up. The sound is loud for a split second but then it quickly fades to barely audible. So i suspect something is up with the BT transmitter not liking the ohms or something. I cant figure it out. I'm bummed man lol

Yep. I just use a battery..

Excellent video. Could you do the following to keep the signal in mono from the very beginning? Example using the Aiyima A07max in mono mode. What if I were to use a pre amp with a non crossed over full range sub out (mono) intended for an active sub; and then ran this to the Aiyima A07 max in mono mode? This way I keep the signal in mono the whole way. Pre amp with full range sub out with no crossover or pass filters.

How did you do the initial conversion?

Hello! I am not sure if you will get this because it's older post. I am trying to see if I can use same unit for a guitar amp and by pass the turntable unit. I am getting same buzz as you did on start up but I am not as well educated on caps and resistors. I do get signal buzz when I touch needle wires but the sound of a loose ground over rides all other.

Hi ! Is it possible to connect the line directly to the AM radio pin to have the sound of the radio in the background for noisy work?

Solución....microswitch abierto

What did you use to clean the MOBO contacts on each component where it plugged in?

Great solution. Thanks for taking the time to help others like me!

What is the model number for the amplifier you're using?

Hi thanks for the video, I have a question regarding the bluetooth module, can you change its name? Im refering to the the name it displays when you search for it with your phone

How much is the value of resistor to use?

Can i get source from the voltage regulator to connect to the isolated dc dc regulator?

TR3 in alls LEADS are wrong position respect the schematic

Finally, a solution, thanks for this.

Q: If the component truly isolates its 2 sides, why are the support component necessary? Doesn't 'no connection' inherently mean that no ripple is passed on at all? Why the extra filtering if there isn't anything there to be filtered? (In other words, I already have the B0505S-1W isolated converter, and may or may not have the inductor and capacitor, but I'm way too lazy to look for them if I don't really need them! lol)

The beauty of this solution is that, unlike other devices that try to filter out the noise that is already there in the audio signal, this method stops the noise from being created in the first place!

Do you sell any of these items somewhere?

Do you have a video showing this build? I didn’t see one.

Very interesting explanation. I don't know a lot about electronics but I was able to follow along. I'm assuming the reason I'm hearing ground loop interference from the Bluetooth transmitter in my car is because it is powered and grounded along with the factory car amplifier. How would I go about getting rid of interference in that case aside from powering the transmitter with its own battery?

Got one of them knobs sitting around?

Had two of those over the last…. 20 years. Never was impressed so I sold them cheap. Damn, should have put good speakers in it and kept one (or both!)

I will try this and let you know the results, though the pins you showed on the transformer were out of shot.

What lube are you using on pots?

Gorgeous!!! Just picked up one of these... The challenge is on...

Trying to do something similar with a couple of old radios but there seems to be so much different information out there on how to do this. I like your use of the battery bank and I wondered if you could provide info on the wiring from bank to the back panel for charging, and the wiring from the bank to the switch/bluetooth board. I have an old radio with a single 3" speaker that I would like to use this configuration for, thanks for any guidance you can provide.

What does the inductor do in this circuit?

I ordered the components, If this works I owe you a beer or three.....

My first amp was an old radio that my friend rigged and sold with the guitar she sold me. The distortion was so awesome, especially when throwing a Boss OD-1 the tone was so creamy when overdriven... Like you said - great practice amp. With the pre-amp of yours and the full volume it's really close. I'd love to hear this with an overdrive.

Hi, Is there any cheapest method available for eliminating ground loop noise?Like you told by filtering it can be eliminated. I have seen most bluetooth speaker uses differential input amplifier to eliminate the ground loop noise. But in my bluetooth speaker configuration I am using single ended class d amplifier so I am not able to eliminate the ground loop noise. I mean other than DC to dc converter is any other method available . Thanks .

Radio lama... 👍👍

Hello, I have an older GE am/fm radio that I converted to an amp in the same way you did here, the board looks very similar to this one, it there are easy way to find and kill the am signal?

Thanks .. your arm and hand in the way..

Nice video, but where have you been?

This video is an absolute godsend to me because I have been frustratingly trying to solve the ground loop in my cars bluetooth module I added. I'm going to give this a shot.

this is helping me in 2021 ty brother

Ne Jamais faire ce qu il FAIT!!! Mettre ce spray SUR les transistors!!!

no, this doesn't work.

can you please explain how to connect R+,R- and L+,L- audio outputs to R,L,GND connector

Would you please tell me what size capacitor and inductor I need if I where to use a 12-12 isolator. Note. It will be for my car so it will be power by a car battery 12v

Hi. I am using these for a a few things now they are brilliant but they die very easy if you make mistakes. But I never used the inductor or cap before. I think without it sounds fine. what are they for?

I've got an old flea market amplified speaker that I was hoping to use for a project like this, but I didn't know (until now) where to connect to; thanks for the great info.

thanks king 🎼🎼🎼🎼

Big mouth billy bass

Thank you!

I need to check and see what’s going on with mine. But I don’t know how to open it up. And you seem to have skipped that process.. any chance you could make a video showing that?

Word of warning: Those small monolithic isolated power supplies like the Murata one shown in the video are in general very poorly regulated, especially at light loads. The datasheet specifies a 10-15% variation in load regulation from 10% load to full load, meaning a "5V" supply could swing as much as 0.75V across its output range (generally just barely acceptable for USB devices). Worse still, they're almost always "unspecified" below 10% load, meaning the regulation is generally awful at very light loads. The Murata datasheet actually states output voltage can rise to as much as TWICE the rated value for loads below 5% (so 10V on that supply), which can easily kill a low-current device that's not expecting it - ask me how I know. Options for avoiding this include: 1. Ensuring you don't "oversize" the converter (make it just big enough for the load current of your bluetooth receiver, keeping in mind if your receiver has a low current "idle" mode when it's not connected to a device) and making sure you never unplug/replug the bluetooth receiver when the circuit is powered. 2. Adding a "dummy load" resistor to draw a bit of current all the time. The shown converter is rated to 200mA, so keeping it above 10% only requires a ~250 ohm resistor that will dissipate 0.1W, so a quarter-watt through-hole resistor would work fine here. 3. Putting in a Zener diode to shunt voltage if it rises above a certain point. A 5.6V or so Zener could do this, but Zeners aren't generally that "sharp" at low voltages like this so it might not regulate much better than the simple resistor, and is more expensive (you're also less likely to have one lying around). Also note that you might run into problems depending on what USB port you're using to power the receiver - if the data lines are connected to something else (like the vehicle), it could prevent you from breaking the ground loop depending on how the rest of the system is wired. Best to ensure you're using a cable or circuit that lacks the USB data lines completely (like the demonstration shown on a breadboard here) to avoid that issue entirely. Otherwise, this is a great alternative approach to an isolation transformer, as it will preserve the audio quality on the analog audio side of the circuit (audio transformers will typically negatively affect audio quality, especially on the high frequencies, at least a bit).

Hello,sorry about my English..is it possible to bypass the radio signal to avoid the buzz noise?If yes,how can I do?Thanks Nizzy!!

I have a TPA3118 mono module. I modded it, decreased to 20db gain. I added a potentiometer for volume adjustment. The pot when full and zero level no noise but at middle levels i m hearing noise. How can i eleminate this problem?