Thank you, you have just saved me a lot of time and frustration. I can turn up my LM4780 to max now and with my ear pressed right against the speaker I can only hear the faintest hint of a hum :)

Great video... we need more like this to help the average techie! Good work

love your videos sir! amplifiers are one of my hobbies so all of this is very interesting and teaching

Hi all. I used 100ohm resistors with my good old Creative SBS A220 speakers and succeeded. Noise is gone. Also that did not make any adverse effects on sound quality when I connected my phone to my speakers. Also thank you very much John for this video.

Use a small board with the BA3121 it will cancel out lots of distortion caused by ground loop. It uses CMR characteristics of the opamp.

Thank you for narrating. Truly.

Commonly, there are two kind of noise in computer PC: ground loop noise (only if you have different grounds connected) and picking up noise signal from audio cable. For ground loop suppression, just buy ground loop suppressor (basically just using transformer). For noise picked from audio cable, you can shield/wrap your audio cable with aluminium foil and connect that aluminium to ground, works for me.

Just to clarify, you might show what that install looks like on a typical amp board (e.g., parts express) with stereo input. Very helpful video. Thx!

Simple solution yet effective, thanks.

Thank you for this! I had to put a 2 resistors, one to ground + left and one to ground + right in order to get both channels silenced... got rid of buzzing by 90%

Hi John. Great Vid. I get the same hum albeit Louder off my Adcom as soon as I turn it on. I did accidentally drop the unit within a box on its side 3ft off the ground. Do you think I may have damaged the caps or need to resolder some points which may have come loose?

This was a nice, simple demonstration of how to potentially kill the ground loop noise in the AUX input in my car. Have to try it out this weekend before I buy a more expensive option.

I was looking for something like this ...I will try your trick . Thanks !

I have just had a look at my crap system in sunroom. Had bad hum the cheap player had no bass and no controls. So I plugged in a scrap amp , got the tone but also got hum . Now put 1k across both inputs and fixed. I was looking for a hum loop. Many thanks.

Yeah it's really work! Thank you. 👍🏼

Thanks for your recomendations

Awesome fix! It worked in eliminating the irritating hum from my DIY subwoofer amp. As I built the normal stereo power amp first, and then this subwoofer amp, I will have to do the same on the stereo inputs on the main amp? Can this be reduced to one single resistor on the initial input, which is the headphone out from my computer instead of three resistors, one for subwoofer amp's mono-fied input, and the two separate left/right inputs on the main amp board? :/

Very useful video, Thank you. I'll try it on my amplified speaker project hopefully that'll get rid of the annoying hum.

It works man, i was facing the same probleme. thanks a lot.

Another way is to use an isolation transformer on the audio or use a larger filter capacitor on the power supply.

Great video - thank you John!

you save my life, John

Hey john, can we use this at each stages, like before preamp, before poweramp etc.

woo, that was easy, thanks John!!!

its workinggg. thank youuuuu

I builded lots of amplifier with Lm4780 / lm3886 / tda7293 and many class A with always the same humm noise trouble ! I try your tips about 1K resistor between the gnd and signal input that help to reduce but not gone at 100% do you have another tips for build a truly silent amplifier ? thanks in advance ! :)

very helpful, thanks for the video

1:18 How Dubstep beat drop be like...

Thanks , it help me a lot, I was tired of shitty noise :)

Hey everyone! Thanks for the views. My first video with over 1K views in under 20 hours. Also, a big thanks to those who answered questions left here in the comments. I can't do it all myself.

Hi John,, Thanks for the great video,, I was wondering what amplifier chip your using in the video and what current and voltage your supplying the chip with,, Sounds Great.. I Still haven't received my PAM8403's from china yet,, boy it sure take a long time,,

Did adding the resister also shunt the feedback when touching the capacitor?

Great fix.It really helped. Thanks bro..

Liked the clip. I would have thought to use a T-Filter. Didn't think to use a low value resistor. Thanks.

This works because you are shorting part of the input into ground through resistor, which makes you amplify less noise. However you also amplify less input, what means that you just lowered the volume. If this was a "simple and no-loss solution" each and every datasheet for an amplifier would included this input resistor as a default part. This obviously is not the case. What you can do as a "lossless" solution is to use special input jacks, which when there is nothing connected to the input short inputs to ground. This causes no hum when nothing is connected and no loss when you actually connect something. You can easily check there is no hum for almost any amp when you connect input connection to ground. Many guitar amp input connectors have this, this is why when you do not connect a cable to the input there is no hum and when you connect one without a guitar at the other end the hum is there and effect is the same as in the video. There are also other factors like cable shielding (especially with very high gain amps), how ground is laid out in the amp circuit, filtering etc. Overall I would not recommend this, since you are removing hum, by lowering the volume, which does not make much sense...

thank you so much ! you help me with this video .

I'll have to try this on my little mono class-d subwoofer amp in my boat =)

I have a mini arcade cabinet box with a PI, LCD screen, joystick driver, and small mono amp in it. The speaker is giving this type of hum and is also picking up interference from the pi. The audio cable from the PI to the AMP is already shielded. Would a simple resistor solution work for this, or do i need to shield ether the PI, the AMP or both? It running retro pi in the case, and apart from the audio buzz it's all running quite well. Apart from the buzz the sound level range from the AMP is fine.

Nice Video ! Truly fix the noise mostly.

Thank you from Algeria!

This is a great video, great explanation! Thanks @JohnAudioT. I have an issue with an active speaker (B&O BeoLab 8000 with built-in amp). It has an RCA plug for line-in that I want to use. And it has an auto stand-by function which means: the amp & speaker switch on when audio signal is coming in, and it (normally) switches off within 3 minutes after the audio signal has ended. I have a kind of distortion that causes buzzing noise. The noise is too loud for the amp to switch to off permanently. It does try to switch off, but then immediately switches back on again. This process repeats continuously. This happens both when I have no external audio source connected to the RCA connector for line-in. As well as when I have an external audio source connected to the line-in. Though the buzz is a little bit less when I plug an iPhone as audio source to the RCA line-in connector. But even with a source connected to the RCA, there still is a lot of sensitivity. Because when I touch the cable that connects the RCA to the AMP, it immediately switches on again. Next I connected a 10K resistor across signal input & ground input. Without an audio source connected, it even increased the buzzing noise. With an audio source connected, the resistor makes no difference. Any ideas/suggestions?

Perfect !!! 👍

can I add a resistor in the input if I want to amplify a mic level signal from a microphone. I bought a cheap PA system which outputs too much noise, even when using the wireless mic or when connected to bluetooth as a bluetooth speaker

Thank you!♥️

what resistor value I'm going to use if guitar to amp? any suggestion value of ohms

Hello, thanks for sharing this video. I have an lm386 guitar amp. The noise comes with nothing connected. I have connected the 1 k resistor as you suggest here, and the noise goes out, like in the video, but with the guitar, affects the volume. So, I have two questions: Does it happen the same attenuation to you, with your earphones out? Have you checked this? And when you talk about shielding, do you mean to use a shielded guitar cable, shield the electronics of the guitar, or both things

Thank u nice explanation

Hello, Boss I saw impedance plug on amazon, will it useful to reduce hum noise? What hms should I choose? Thanks a lot.

How about the volume, it would be decrese or go down right? Tx u sir 🙏

Thanks for sharing sir

So how can we do this with the class D aliexpress amps? Not sure where to look on where to put the resistor over the input.

How are you, Mr. John, I hope you are always healthy. I am your fan. Resistors are installed before or after the Tone control ' I'm Waiting for Your Reply, Thank You Very Much 🤗🤗🤗

When you say "across amplifier input", does that mean, i connect both ends of the resistor to the negative and positive of the input? So if I have a stereo input, then I should put on both channels? Connecting the left channel to the ground, and right channel to the ground as well? Like this: L-(1Kohm)-G-(1Kohm)-R

Very powerful video

Thanks. I was making a circuit for a guitar on a breadboard. Turns out, I just needed to shorten the antenna. I mean shorten the leads to the output jack. Problem solved.

I cant open my current speaker set up(atleast not without breaking it). Are there thing i can to the 3,5mm to improve it? Like an adapter or something

Hey John. Thanks again for your informative videos. I have a Dayton Audio Bluetooth amp. I think they us TPA3116 chip. There is a bit of background hiss at lower volume. Is there a way to get rid of this without desoldering or changing SMD components on the chip? Would adding a volume control (acting as a resistor) do the trick or am I stuck with it? Cheers

They have 75 hms to 600 hms impedance plug(3.5mm). May I know which one should I use for my v8 sound card? The wire is about 30 meters long

Will this work on PAM8403 amplifier. If yes then what is the resistor value will be?

hey can you make something like single coil guitar pickup hum canceller, like musicman active silent circuit? umm i hope you'll know what guitarist problem. there's the US patent diagram on google, but they (musicman) kept the resistor value confidential. btw, nice channel..very informative.. just subscribed to you

good video and thank you so much

Thats what i wanted to know! Thanks for upload!

Very nice solution! Simple but effective.

Where can i find that little sony player ??? Whats the name or number of it ?? Thank you

Your video is the only one so far that has the same EXACT buzzing that I'm hearing coming out of my speakers that I hooked up to my television. They can be used on a tv or computer they used to be on my computer & worked fine. Hooked them up to my tv & the audio works but there is the buzzing (same exact sound in your video here). For the past 3 days have tried all kinds of fixes, all kinds of wires, went to the store & bought different wires, etc. nothing works, constant buzzing. I've heard of something called a ground loop isolator, not sure if that would work but the buzzing is driving me nuts. I can hear audio just fine but during quiet scenes in a show the buzzing is there, I can also hear the same thing you did when I tap my fingers against the end of the prong (the end of the plug)....it did not buzz when it was hooked up to my computer, only when hooked to my tv. Not sure if a ground loop isolator would work, it's my last resort, if the isolator won't work I'm disconnecting them & Putting the speakers back on my tv but I cannot for the life of me figure out how to stop the buzzing, been 3 days now & tried everything I possibly could to no avail.

i got a long 5 meter headphone extension cable but it is next to power wire and it hums a lot and when i plug in headphones it pops loud.

Hi! I have a TPA3118 60w mono class D amp, wirh a 12v 1,5a power source from a dtv tv deco, connected to a 12v chinese bluetooth/radio/usb module, i wann hook up a volume potenciometer (i have a 10k and a 100k). Sounds loud and cool, the thing is that i get a lot of noise, i maybe put a B1212S, just guesing, and i dont know wich of the volume potenciometer put either, recomendation for the noise and the potenciometer? (first speaker project, and sorry for my english) Best regards from Argentina!!

So my 5.1 amp Stereo is 7294 ic dual sub irfp150mosfet surround is tda2030 4 ic centere is tda 2030 2 ic ....i have this small noise issue....Which resisters use to reduce noice? ...i am also use shielded cables for all inputs to volume control and amplifier ...

L'alimentazione è meglio swiching o stabilizzata?

So I have a TPA3116D2 Dual Channel class D amplifier board and I'm using it with a separate Bluetooth amplifier and when Bluetooth is turned it makes like a 5k hz noise but when I'm using aux through the Bluetooth amplifier it doesn't make any sound. And I've tried the Bluetooth amplifier on another amplifier but it doesn't make any sound when Bluetooth is connected, what could be wrong?

Nice. Very Good.

That was especially worthwhile John....

nice tip !!!

Does the resistor decrease max output?

WOW i have build a few amps in past month (just for fun) and i thought that only way to get rid of that input noise is to go ham on shielding input cable. Its really simple solution and it does work. I have one question and i think that you could help me with (if you have time to reply of course). I have Samsung TV with great panel but it surprisingly lacks any sound output but i can disassemble it ant tap some female RCA connectors on speaker but since i need line out not amp out will a few resistors in series do the job or i would have to do some voltage divider to bring the voltage to line level input,on my amp it says Sensitivity : 150mV and Impedance: 50kiloOhms . Thanks in advance

Can i use for 5v amplifier board like pam8403

does this work with guitar amps

very good video, I have a question if I want to eliminate the noise of "local radio reception", can I solve it in the same way?

Hi! And what if my TDa2030a kit dont have any buzz without volume control but have buzz with it. What can i do? (I tried other potmeters aswell) Thanks for you answer! Great videos by the way!

Great video! But actually I find it working just fine with resistor also for instrument input. But at like four times the DC resistance of the guitar pickups, ie 20 kOhm. At least when the signal meets a capacitor and then an op-amp.

If I don't have a board like that, can I solder in between the wires somewhere

I get a lot of humming while using my phone through the mixer ,, what device ,, which way is the best way around .. which isolator is the best one to use .. (inexpensive

You put the 1k resistor across what 2 pins of the input though? There are 3 wires on my input side, LEFT, RIGHT and GROUND. Are you putting the resistor across the LEFT and RIGHT pins? Or across LEFT and GROUND or RIGHT and GROUND?

Dang, wish I had seen this 2 months ago. It would have saved me hair pulling on my DIY build.

How Dubstep was Discovered XD 1:18

i have a peavey pa amp head how would i quieting it itss a little hum and alot of wind its 260 watts...great hope u can help me thx alot

At the start of your video you show a pre-made amp, i have purchased an almost identical one of these very recently and need to reduce the noise. It has the same 3pin input as yours showed with L R and Ground. What would be the best method of inserting a 1K resistor on the input in this instance ?

Hello, I have that horrible noise I connect my turntable to a pre-phono in and out to a sansui amplifier on tape, even if I plugged in the ground wire that horrible sound follows, what can I do

Couldn't you build a ground loop isolation circuit? Basically you transfer the audio signal into another circuit by magnetic transfer which would eliminate noise on the current line, through a couple of coils, or a transformer...? I know this would eliminate any "leaking" dc currents... Then smooth it out with a few caps?

ok, im confused. you gotte bridge the positive and negative leads? wont that short the signal?

Which resistor for pc pls reply

How can I eliminate noise/static in my house when I turn on the Treadmill, anywhere in house?

How would you apply that to a hand radio

Across the L & R input ? Not the ground at all ?

John, good day. Mine has problem like someone is coking. Its on and off though.

fascinating

What resistor is that?or the label?

tthnks very very much

HELLO i have a question did you put the resistor in between the GND? or did you connect it to the left and right source

What is the IC number you are using, do you give me its Circuit Diagram please...