Actually this is not a new solution for that kind of problem. It`s state of the art. The designer of the IC makes the analysis of the circuitry whit consideration that the power supply connection (Pin 6) is a short to ground for AC signals. As you have discovered this is easily done by using a bypass capacitor between the power pins. Usually that cap is kept as close a possible to the IC. Without this capacitor,depending on the length of the power wires from the power supply, the amp can become unstable and begin to oscillate, what probably happened in your case. The usual technique is to put two caps parallel to the power pins of the IC. One cap is an electrolytic one which is able to bypass the low AC frequencies the other one is a sort of ceramic or other types which are able to by pass the higher frequencies. Butting only a electrolytic cap eliminates the low oscillations, which you hear through the speaker, but can sometime let oscillating the amp in higher frequencies modes even around 1MHz which your speaker can`t reproduce. The amp works properly anyway in his designed frequency range, you can hear some music but still oscillate on a higher frequency.
Hi HH, Just a little FYI, proper ground layout is really important with the LM386 and with any other chip amp. A separate ground path for input, power and output, the Star Grounding technique, as per John Audio Tech on YT. All the ground paths should junction right at pin 4, GND. Filter cap should be as close as possible to pin 6 and 4. Be good, C.
Thank you, Mr. Heilman. Very generous and informative video. You, sir, are most kind! I just received an order of a few LM324 (Quad) Op Amps, and am intending on building a similar stereo amp for use as I begin building simple -- eventually more complex audio oscillators, filters, etc. and one (or more?)16-Step Sequencers. I've seriously been bitten and smitten by the whole Euro Rack Synth Modules thing, late to arrive as I am. I will certainly apply your tips as well as some others offered by other kind, generous commenters. It's wonderful to show what you know, it's a true gift to educate. THANK YOU!
"Problem solved" ... Not really, problem created removing it. The decoupling cap must be as close as possible to the chip with a 100nF ceramic cap. And by the way, it is not noise, it is oscillation.
I didn't realize how bad the noise can be, and with a simple capacitor, it'll all go away. Now I understand why there are more capacitors than the basic circuit design.
Your power supply is outputting chopped up DC, probably pulse width modulated with inadequate smoothing. If you run into a situation where a capacitor alone isn't enough without so much capacitance it isn't feasible, an inductor before it in series will push it over the top, however, it will trade spiky ripple with slow voltage drift. This is only an option if you are using dirty DC to feed a voltage regulator. Then the voltage out of the regulator will be smooth as a baby's bottom. Basically: Dirty DC -> 2.5-5mH inductor -> Capacitors -> LM317 -> Absolutely prestine DC with no noise.
This is no noise. It is oscillation. Sufficient grounding is essential. The ground point with the lowest ac impedance has to sit as close as possible to the ground pin of the chip amp. This point is usually the minus pole of the electrolytic buffer capacitor. This buffer capacitor should be paralleled with a ceramic capacitor of 100 nF in order to short also higher frequency oscillations which are not audible but a load for the chip amp. And, as Cass Virgillo wrote, use separate ground paths from this ground point to the input and output ground.
@@69iqtutorial it is in general not so easy to make a sufficient design based on the LM386. There must be several things taken into account. This IC is very sensitive to oscillation because of its inner circuit design. Star grounding around pin 4 is essential. The Zobel output filter ist essential and there should also be a capacitor of 47 pF between non-inverting input and ground in order to low pass filter the input signal from hf. It is also not wise to bridge the inner 50 kOhm resistor between one of the IC's inputs to ground. So the inverting input should be grounded via a capacitor of 1 to 10 µF. Otherwise the input differential amplifier becomes unbalanced which lead to output offset and therefore lower maximum output power. There is also another problem due to direct grounding of the inverting input. The differential amplifier becomes more nonlinear leading to more THD. In fact, you can operate the LM386 with significantly lower THD (less than 0.1%) as shown in the data sheet when you use capacitor bridging instead of direct bridging of the inverting input.
You can also connect a capacitor from pin 7 (Bypass) to ground, which ought to stabilise it a bit more and potentially remove a bit more noise. The datasheet doesn't give a value but since it's for smoothing, it can be as big as you like. 10uF seems enough; maybe even less.
I am using a pam8403 class d amp module and when I put a capacitor across vcc and ground it only makes more noise than there already is now when I use an addresable led strip near that amp like the ws2812 it make some stronger humming noise unless the input wire is being disconnected and I wonder why?
that noise likely wont be a problem in the first place if you're using a battery as the power supply. it just sounds like switching noise from the power supply you're using but as noted below you should have a bypass cap "filtering" the input anyway because its an audio circuit and once you get past a few dozen Hz inductive effects on the ground plane ( just a wire here) can no longer be ignored. also as noted below, you shouldn't need nearly as large of a cap. its also worth noting that electrolytics alone aren't necessarily ideal for this purpose but they'll do fine as long as you're not using this to pre amp for a much more powerful amplifier. nominally you would want a mylar or silver/mica in parallel with a decent electrolytic because they can respond much faster to the sudden power needs and have a much more stable esr over a wider range of frequencies, but thats going all audiophile and junk.
Atlas WalkedAway, do you have such a schematic to offer here on TH-cam? No pun intended, but your comment 'sounds' very interesting. I'd like to try something like this as well as the one offered in this video. Thanks, Sarah
A low ESR capacitor is fine, and typically, the bigger the better. The larger the cap, the better it is at removing ripple, but not if it comes at a cost to ESR. Electrolytic and a film/mica/ceramic cap in parallel is the best of both worlds. I don't recommend ceramic if powering speakers, cause of microphonics causing feedback. Low esr caps are easy to spot because, surprise surprise, they are labeled as 'audio grade'. Also, even when using a battery as the power supply, you will have problems with distortion due to voltage droop due to the batteries internal resistance. This is also fixed by the cap across the power input.
If you Google lm386 audio circuits you will find a lot of different uses for it and how to increase the gain of the chip. It's been around a while but it does its job well. Hope this helps. ps a good place for audio is diyaudio.com. @@Sarahbuildsstepsequencers
Pin #7 is a Bypass for the Input Transistor's Collector... run a 0.1uf capacitor to ground. This will help with noise immunity. Another good practice, is to use an 100 ohm resistor between your power source and the Pin #6 power input, and place an electrolytic capacitor as close to Pin #6 and ground. You should also ground the Zoble Network and the Speaker as close to the LM386's ground pins.
The LM386 is also noted as an AM detector and very sensitive to RF fields. I use 100uF to pin 7. The TDA2003 is good except it has poor supply line noise rejection and needs a lot of components and pulls around 30 mA minimum. I sure someone knows the best audio chip out there however fame equates to availability
Thank you for that, mine didn't make the noise like yours, but it was getting a lot of interference from TV and radio, after I put the Cap. it worked fine. ( I had a 450uF cap on hand and that's what I used)
For some reason if I bridged pins 1 and 8, then bridge it to pin 2 ( which is also grounded ) it also removes all the noise, well my circuit is slightly different from his but never the less the same without the second capacitor between VCC and Ground. Im here to ask someone, why did connecting pins (1 & 8) then to 2 removes all the noise in my setup? Thanks in advanced.
Well, if you look at the datasheet recommended circuit, the capacitor is clearly shown there, between the power supply and ground. I don't think you need to be a genius to read a datasheet and design a circuit properly :-P After all such capacitor is necessary in every power amplifier. This has been known for about 80+ years, starting from tube amplifiers in 1920's...
I had made a amp with this chip about a month ago and i had the same problem but i put a LC filter or just an inductor from pin 5 to ground and it removed all the noise to me!
I guess I've been lucky, but nothing I've built with a 386, even when I place a 10uf electrolytic between pins 1 and 8 for max gain (200x), has ever caused me noise problems. However, I like the cure you present; don't think I was aware of it, and don't believe it even appears on the IC datasheets I've seen.
If the wires running from your power supply is longer than 10 centimetres you must use filter capacitor else it will motorboat like this. I faced the same in case of building tda2030A amp circuit
HI everyone, I'm working on this project> When i tried the cap as u said in proteus it feels like it increased the pitch. Can anyone put some light on it.
This is a cry for help not criticism. I love the video, it's exactly the problem I'm trying to learn about. BUT, I'm New, I'm trying hard. You move the old Board so fast I can never get a good look. Help Me, did you bring the VCC( the pos input voltage) straight into the bread board and not hook it to the +/- feed on the outside 2 rows of breadboard? Looks like you go straight from output speaker to the outside +/- seemingly defeating the pin 5 capacitor and resistor. It also looks like you have a POS feed going through the pin 5 Cap and R - > to the speaker as diagrammed. Also Pin 3 should hit the 10k R then move on. Is the jumper from pin 2->pin 4 allowing you to shift the pin 3 1k R to pin 4, in a straight line due to the 2-4 jumper? If I make No Sense, I completely understand. Sincerely, ...........NBSTATIC.
Tis your power supply ripple. If you run your circuit on a battery, this doesn't happen, because the power supply is perfectly smooth, though it's still advisable to bridge the Vcc and GND pins of the IC - with the shortest route possible - using a 100nF cap (1206 SMD ceramics are the best for this purpose as you can connect them nice and easy without introducing a parasitic inductance). This little cap will help provide short bursts of energy with low latency when a battery or power supply has a much longer response time to provide the necessary power.
Whenever i plug the jack in my mobile while the circuit is powered, my mobile screen starts to act strangly, i have tried the circuit with different mobiles but still face the same problem. Its like some current flow into mobile through the ciecuit
Damn, it was the noise from your PSU :( I have a battery-powered circuit with LM386, producing some pretty loud hissing noise. Putting a capacitor on the supply wires has no effect (not a guess, actually tried it). Filtering the output has some effect though, but muffles the useful signal as well.
hi, Can you please make a video to show us what is the difference between sounds with and without amplifier. This is very interesting. Nice video BTW 👍
I agree, I like your way of cutting out the unnecessary over explaining and getting to the crux, just remember there are self taught dummies w no study group partners and a few Bread Board basics from even tiniest shortcut, once explained, could make a light bulb go off for beginners. Sincerely........................NBSTATIC .
I believe pin 2 is always grounded and another pin has a cap to cut out am radio interference, if you mess around with these chips and make a good crossover for your speakers and use all good components the sound quality can be hi fi quality, much better than most boom boxes and so on.
well... you have problem you make your in 20 gain set if you want to make much hi gain set in 200 just plug mylar .2 uf in pin 1,8 and put some a resistor that has resistance 22k in input of ic parallel in the ground filtered much the sound stability and .1 uf electrolytic into input of you put in the pot it will much filtered block the unwanted noise in the device and make the input signal will much fidelity and in my opinion you make the amp much better in crank just put 2200 or 3300 uf electrolytic so it will boost the watts yet filtered pwr source and parallel again a .1uf mylar so the unwanted noise go out and much no noise and the last to balance the low to hi freq ratio to output just put a .47 uf mylar parallel to resistor 1 ohm to gnd so it will just the bass will came out yet in hi freq and last put a .47 uf maylar in pin 7 so the sound way perfect in 99% sure the amp will be in hi fidelity and no distortion at all promise you make what I mean so it can be the pure and potential of that ic will came out promise to you but da next secret is I almost forgot is parallel again a 1k uf in 330 uf in output so the signal from amp is so filtered that I can tell you can fabricated and sell a radio amp no noise no distortion even in full volume of the amp
Actually worked sweet with a 100! seems everyone has a different technique for getting rid of that hum! no hum with a battery (9v) but such a dreadful noise with a power cable plugged into mains!
The default 20x gain from line level (such as this music player, phone and pc outputs) is kinda too much as it is for a 0.5-1.0W chipamp. Thing starts clipping pretty easily. The 200x setting is more useful for amplifying much weaker signals like those from electric guitars and microphones. But 200x line level, even with the maximum safe input voltage, it clips a LOT and sounds awful!
I am using a bench power supply, which does have some ripple under load, but I had a similar result with batteries, seems like there was resonance from the speaker.
0.1uf axial cap and 1000uf in output 100uf for input and gain 820uf for feedback pin P.s all caps are made in Japan I find that old stuff in my local store
It was. His specific flavor of noise. However, even if it were clean, the op amp itself will dirty it's own supply voltage adding distortion without a cap in exactly the same place. It needs it either way.
I know the best configuration for the LM386. Try this one: (# 1) a 10uF CP across pin 1 and pin 8. (#2) connect pin 2 and pin 4 to the negative terminal of a electrolytic CP (1000uf) connect pin 7 to the positive terminal of the same capacitor. Than you you know the rest
Actually this is not a new solution for that kind of problem. It`s state of the art. The designer of the IC makes the analysis of the circuitry whit consideration that the power supply connection (Pin 6) is a short to ground for AC signals. As you have discovered this is easily done by using a bypass capacitor between the power pins. Usually that cap is kept as close a possible to the IC. Without this capacitor,depending on the length of the power wires from the power supply, the amp can become unstable and begin to oscillate, what probably happened in your case. The usual technique is to put two caps parallel to the power pins of the IC. One cap is an electrolytic one which is able to bypass the low AC frequencies the other one is a sort of ceramic or other types which are able to by pass the higher frequencies. Butting only a electrolytic cap eliminates the low oscillations, which you hear through the speaker, but can sometime let oscillating the amp in higher frequencies modes even around 1MHz which your speaker can`t reproduce. The amp works properly anyway in his designed frequency range, you can hear some music but still oscillate on a higher frequency.
Hi HH, Just a little FYI, proper ground layout is really important with the LM386 and with any other chip amp. A separate ground path for input, power and output, the Star Grounding technique, as per John Audio Tech on YT. All the ground paths should junction right at pin 4, GND. Filter cap should be as close as possible to pin 6 and 4. Be good, C.
Cool, thanks for the information.
I love John audio videos very much
Thank you, Mr. Heilman. Very generous and informative video. You, sir, are most kind!
I just received an order of a few LM324 (Quad) Op Amps, and am intending on building a similar stereo amp for use as I begin building simple -- eventually more complex audio oscillators, filters, etc. and one (or more?)16-Step Sequencers. I've seriously been bitten and smitten by the whole Euro Rack Synth Modules thing, late to arrive as I am. I will certainly apply your tips as well as some others offered by other kind, generous commenters. It's wonderful to show what you know, it's a true gift to educate. THANK YOU!
Thank you so much for posting this. Saved me (and my lab buddy) a whole lot of time!
Glad it was helpful to you.
but noise coming from him psu not internal oscillation.Because of that it is not a solution.
"Problem solved" ... Not really, problem created removing it. The decoupling cap must be as close as possible to the chip with a 100nF ceramic cap.
And by the way, it is not noise, it is oscillation.
I didn't realize how bad the noise can be, and with a simple capacitor, it'll all go away. Now I understand why there are more capacitors than the basic circuit design.
Dude, you save my life! Thanks!
u best man and your english is perfect to understand for me!
Thanks for showing the problem and basic solution to handle it.
hi. i know capacitors can be used to eliminste noises. but why vcc to grnd? can someone explain?
good matt, i like lm386 and had same problem.
nice video
Had same issue - this fixed it for me - thanks very much really helpful...
Hey, Thank you for your nice video. You explained it very nice way. Specially with the schematic....
The capacitor works even for voltage supply by the battery. Very good advice. Thanks
Your power supply is outputting chopped up DC, probably pulse width modulated with inadequate smoothing.
If you run into a situation where a capacitor alone isn't enough without so much capacitance it isn't feasible, an inductor before it in series will push it over the top, however, it will trade spiky ripple with slow voltage drift. This is only an option if you are using dirty DC to feed a voltage regulator. Then the voltage out of the regulator will be smooth as a baby's bottom.
Basically:
Dirty DC -> 2.5-5mH inductor -> Capacitors -> LM317 -> Absolutely prestine DC with no noise.
I knew my supply was dirty so I fed it into another regulator board with a few caps on it just for good measure.
Useful info. Thanks for sharing that solution!
This is no noise. It is oscillation. Sufficient grounding is essential. The ground point with the lowest ac impedance has to sit as close as possible to the ground pin of the chip amp. This point is usually the minus pole of the electrolytic buffer capacitor. This buffer capacitor should be paralleled with a ceramic capacitor of 100 nF in order to short also higher frequency oscillations which are not audible but a load for the chip amp. And, as Cass Virgillo wrote, use separate ground paths from this ground point to the input and output ground.
True and little false both at the same time...
@@69iqtutorial it is in general not so easy to make a sufficient design based on the LM386. There must be several things taken into account. This IC is very sensitive to oscillation because of its inner circuit design. Star grounding around pin 4 is essential. The Zobel output filter ist essential and there should also be a capacitor of 47 pF between non-inverting input and ground in order to low pass filter the input signal from hf.
It is also not wise to bridge the inner 50 kOhm resistor between one of the IC's inputs to ground. So the inverting input should be grounded via a capacitor of 1 to 10 µF. Otherwise the input differential amplifier becomes unbalanced which lead to output offset and therefore lower maximum output power. There is also another problem due to direct grounding of the inverting input. The differential amplifier becomes more nonlinear leading to more THD.
In fact, you can operate the LM386 with significantly lower THD (less than 0.1%) as shown in the data sheet when you use capacitor bridging instead of direct bridging of the inverting input.
God bless you!
Thanks a lot for your help!
Me ayudaste mucho , tenía ese problema y no aparecía en ningún esquema . Ya estaba loco . muchas gracias , un me gusta y suscrito .
You can also connect a capacitor from pin 7 (Bypass) to ground, which ought to stabilise it a bit more and potentially remove a bit more noise.
The datasheet doesn't give a value but since it's for smoothing, it can be as big as you like. 10uF seems enough; maybe even less.
I am using a pam8403 class d amp module and when I put a capacitor across vcc and ground it only makes more noise than there already is now when I use an addresable led strip near that amp like the ws2812 it make some stronger humming noise unless the input wire is being disconnected and I wonder why?
that noise likely wont be a problem in the first place if you're using a battery as the power supply. it just sounds like switching noise from the power supply you're using but as noted below you should have a bypass cap "filtering" the input anyway because its an audio circuit and once you get past a few dozen Hz inductive effects on the ground plane ( just a wire here) can no longer be ignored. also as noted below, you shouldn't need nearly as large of a cap. its also worth noting that electrolytics alone aren't necessarily ideal for this purpose but they'll do fine as long as you're not using this to pre amp for a much more powerful amplifier. nominally you would want a mylar or silver/mica in parallel with a decent electrolytic because they can respond much faster to the sudden power needs and have a much more stable esr over a wider range of frequencies, but thats going all audiophile and junk.
Atlas WalkedAway, do you have such a schematic to offer here on TH-cam? No pun intended, but your comment 'sounds' very interesting. I'd like to try something like this as well as the one offered in this video.
Thanks, Sarah
A low ESR capacitor is fine, and typically, the bigger the better. The larger the cap, the better it is at removing ripple, but not if it comes at a cost to ESR. Electrolytic and a film/mica/ceramic cap in parallel is the best of both worlds. I don't recommend ceramic if powering speakers, cause of microphonics causing feedback.
Low esr caps are easy to spot because, surprise surprise, they are labeled as 'audio grade'.
Also, even when using a battery as the power supply, you will have problems with distortion due to voltage droop due to the batteries internal resistance. This is also fixed by the cap across the power input.
If you Google lm386 audio circuits you will find a lot of different uses for it and how to increase the gain of the chip. It's been around a while but it does its job well. Hope this helps. ps a good place for audio is diyaudio.com. @@Sarahbuildsstepsequencers
Pin #7 is a Bypass for the Input Transistor's Collector... run a 0.1uf capacitor to ground. This will help with noise immunity. Another good practice, is to use an 100 ohm resistor between your power source and the Pin #6 power input, and place an electrolytic capacitor as close to Pin #6 and ground. You should also ground the Zoble Network and the Speaker as close to the LM386's ground pins.
The LM386 is also noted as an AM detector and very sensitive to RF fields. I use 100uF to pin 7. The TDA2003 is good except it has poor supply line noise rejection and needs a lot of components and pulls around 30 mA minimum. I sure someone knows the best audio chip out there however fame equates to availability
Thank you for that, mine didn't make the noise like yours, but it was getting a lot of interference from TV and radio, after I put the Cap. it worked fine. ( I had a 450uF cap on hand and that's what I used)
Awesome :) glad it worked for you.
Looks like that noise was coming from the power supply, you should probe first with a battery 9v becouse is a low noise source of suplly
deberianos dejarnos el diagrama o pcb para realizarlo...muy interesante gracias...
If I have two speakers bridged, do I have to add a 250microfarad to both speakers or just the first positive?
For some reason if I bridged pins 1 and 8, then bridge it to pin 2 ( which is also grounded ) it also removes all the noise, well my circuit is slightly different from his but never the less the same without the second capacitor between VCC and Ground.
Im here to ask someone, why did connecting pins (1 & 8) then to 2 removes all the noise in my setup? Thanks in advanced.
Hey dude you are a genius! Thank you for this video, really!
Well, if you look at the datasheet recommended circuit, the capacitor is clearly shown there, between the power supply and ground. I don't think you need to be a genius to read a datasheet and design a circuit properly :-P After all such capacitor is necessary in every power amplifier. This has been known for about 80+ years, starting from tube amplifiers in 1920's...
@@ok4rm Ok next time do your video and let's see!
This is EXACTLY the awful noise I'm getting on mine, thanks I'm going to try it
If you want some more gain, add a 10uF cap between pin 1 and pin 8.
Can u tell me a circuit that removes noise from the input signal and obtains rectangular pulse in the output
I had made a amp with this chip about a month ago and i had the same problem but i put a LC filter or just an inductor from pin 5 to ground and it removed all the noise to me!
I have an application where I actually need the noise. How do you aggravate the noise?
I guess I've been lucky, but nothing I've built with a 386, even when I place a 10uf electrolytic between pins 1 and 8 for max gain (200x), has ever caused me noise problems. However, I like the cure you present; don't think I was aware of it, and don't believe it even appears on the IC datasheets I've seen.
That was awesome!!!
Sisters of Mercy - Yeah
A good power-supply filter circuit AND a differential-input to the amplifier could be a solution.
If the wires running from your power supply is longer than 10 centimetres you must use filter capacitor else it will motorboat like this. I faced the same in case of building tda2030A amp circuit
hello engineer do you have a page where this diagram and your list of materials ???
HI everyone, I'm working on this project> When i tried the cap as u said in proteus it feels like it increased the pitch. Can anyone put some light on it.
Is that a high pass filter at the output ? Via 10ohm and .05uf?
Straight up knowledge bomb
Many thanks my friend!!!
me re sirvio , gracias y likes y nuevo suscriptor
How bout distortion pedal noise as well ? Budd
what is the code of capacitor (from vcc to gnd ) ?
thank you matt!!!!
This is a cry for help not criticism. I love the video, it's exactly the problem I'm trying to learn about. BUT, I'm New, I'm trying hard. You move the old Board so fast I can never get a good look. Help Me, did you bring the VCC( the pos input voltage) straight into the bread board and not hook it to the +/- feed on the outside 2 rows of breadboard? Looks like you go straight from output speaker to the outside
+/- seemingly defeating the pin 5 capacitor and resistor. It also looks like you have a POS feed going through the pin 5 Cap and R - > to the speaker as diagrammed. Also Pin 3 should hit the 10k R then move on. Is the jumper from pin 2->pin 4 allowing you to shift the pin 3 1k R to pin 4, in a straight line due to the 2-4 jumper? If I make No Sense, I completely understand. Sincerely, ...........NBSTATIC.
Tis your power supply ripple.
If you run your circuit on a battery, this doesn't happen, because the power supply is perfectly smooth, though it's still advisable to bridge the Vcc and GND pins of the IC - with the shortest route possible - using a 100nF cap (1206 SMD ceramics are the best for this purpose as you can connect them nice and easy without introducing a parasitic inductance). This little cap will help provide short bursts of energy with low latency when a battery or power supply has a much longer response time to provide the necessary power.
Supply capacitor is crucial but frequently not shown in schematic.
Cheers from Indonesia
Skema kaya gitu bisa di aplikasikan buat mengurangi noise di efek gitar ngga ya ?
Thanks for this info... :)
Whenever i plug the jack in my mobile while the circuit is powered, my mobile screen starts to act strangly, i have tried the circuit with different mobiles but still face the same problem. Its like some current flow into mobile through the ciecuit
Damn, it was the noise from your PSU :( I have a battery-powered circuit with LM386, producing some pretty loud hissing noise. Putting a capacitor on the supply wires has no effect (not a guess, actually tried it). Filtering the output has some effect though, but muffles the useful signal as well.
hi,
Can you please make a video to show us what is the difference between sounds with and without amplifier.
This is very interesting.
Nice video BTW 👍
I agree, I like your way of cutting out the unnecessary over explaining and getting to the crux, just remember there are self taught dummies w no study group partners and a few Bread Board basics from even tiniest shortcut, once explained, could make a light bulb go off for beginners. Sincerely........................NBSTATIC .
sorry that's not noise - that's your LM386 oscillating
I guess some noise could come from the audio wires not being insulated.
Thank you!
So what caused the noise in the first place?
I believe pin 2 is always grounded and another pin has a cap to cut out am radio interference, if you mess around with these chips and make a good crossover for your speakers and use all good components the sound quality can be hi fi quality, much better than most boom boxes and so on.
I've used a 450 pF it work as well.
Thank you
well... you have problem you make your in 20 gain set if you want to make much hi gain set in 200 just plug mylar .2 uf in pin 1,8 and put some a resistor that has resistance 22k in input of ic parallel in the ground filtered much the sound stability and .1 uf electrolytic into input of you put in the pot it will much filtered block the unwanted noise in the device and make the input signal will much fidelity and in my opinion you make the amp much better in crank just put 2200 or 3300 uf electrolytic so it will boost the watts yet filtered pwr source and parallel again a .1uf mylar so the unwanted noise go out and much no noise and the last to balance the low to hi freq ratio to output just put a .47 uf mylar parallel to resistor 1 ohm to gnd so it will just the bass will came out yet in hi freq and last put a .47 uf maylar in pin 7 so the sound way perfect in 99% sure the amp will be in hi fidelity and no distortion at all promise you make what I mean so it can be the pure and potential of that ic will came out promise to you but da next secret is I almost forgot is parallel again a 1k uf in 330 uf in output so the signal from amp is so filtered that I can tell you can fabricated and sell a radio amp no noise no distortion even in full volume of the amp
put 450uf capacitor between pin 7 and ground to get rid of any noise and put high capacitor on the power gate
thanks! this was the ONLY thing that worked for me! tried grounding so many things with capacitors, but hadn't thought of this one. Thanks!
Actually worked sweet with a 100! seems everyone has a different technique for getting rid of that hum! no hum with a battery (9v) but such a dreadful noise with a power cable plugged into mains!
damn.... it stopped working again.. lasted about 30 seconds... then the noise came back!
10uf cap from pin1 to 8, then take the cathode of an SB140 schottky rectifier and connect it to pin 8, connect the anode to pin 4. Noise gone.
How can you forget the cap that provides the gain?
The default 20x gain from line level (such as this music player, phone and pc outputs) is kinda too much as it is for a 0.5-1.0W chipamp. Thing starts clipping pretty easily. The 200x setting is more useful for amplifying much weaker signals like those from electric guitars and microphones. But 200x line level, even with the maximum safe input voltage, it clips a LOT and sounds awful!
just power supply issue, are you using bench power supply or any sort of AC to DC adapter?
I am using a bench power supply, which does have some ripple under load, but I had a similar result with batteries, seems like there was resonance from the speaker.
I'm using one of those USB powerbank, quite nice, rechargeable and high density
my woofer has noise.how can i get reed of it
Thanks!
nice video ,would you gie me your schematic this circiut and the lis off the komponen??,please
Would you like the schematic in Eagle or LTSPICE format?
yes ,i have eagle software ,nice,thx bro
Please sir Dolby NR circuit uploaded.
awesome thanks pro
0.1uf axial cap and 1000uf in output
100uf for input and gain
820uf for feedback pin
P.s all caps are made in Japan
I find that old stuff in my local store
Nice post
This was also my problem with the LM386.
Voy a probarlo
Can you please post the schematics
Thankyou ihave this probleme but now Has disappeared
not fix. circuit just need it
looks like that noise was caused by switching within your power supply
It was. His specific flavor of noise. However, even if it were clean, the op amp itself will dirty it's own supply voltage adding distortion without a cap in exactly the same place. It needs it either way.
And here i was losing my mind
Much better, still not so good yet though.
Diodes, who needs them! Arrive at: 'Circuit Solver' by Phasor Systems on Google Play.
Naice
I know the best configuration for the LM386. Try this one: (# 1) a 10uF CP across pin 1 and pin 8. (#2) connect pin 2 and pin 4 to the negative terminal of a electrolytic CP (1000uf) connect pin 7 to the positive terminal of the same capacitor. Than you you know the rest
muito bom
3
pin 2 aint ground, pin 4 is.
Bauhaus
😱😱😱😱😱😱😱😱
your video quality and annoying music are reminiscent of Indian people electronics assembly videos. Next.