Seeing this circuit is one thing, but having the reason for peripheral components explained in a very clear manner is a total other ballgame. Thank you so much... wish I would have gotten into this when I was younger, but no time for regrets!
I understood SO MUCH with your video than in any video I have watched. I'm serious! Thanks for your explanation of this circuit! You are really great teacher.
As an Advanced avionics tech at Boeing for 30 years I saw a lot of engineers with book knowledge and no practical experience with real life application. It was our job to lead the engineers as what a circuit really did in real life circumstances compared to paper
Thank you. I learned more in 12 minutes than I have in the hour I spent poking around the web. The only thing I missed was why you added the 10uF cap between the audio source and pin 3. I assume it is used to prevent clipping or filter out AC voltage. Again, many thanks from an old guy trying to learn new tricks!
+Rick Schrager I'm glad the video was helpful. The cap is there to block any potential DC voltage from flowing into the input of the amp. It only allows AC voltage (the audio) to pass.
I really enjoy your video’s, the explanation and practical uses of the circuitry. Sometimes I have a hard time following because I was thought electron current flow but you explain things from a conventional current flow, also known as (Hole Flow). I know either works but it’s still rather difficult seeing it explained in a different direction. Maybe you can share something that could help me?
Hey, great video. I took this information and built an amplifier using the LM386. As a source, I used my Siglent SDG805 function generator and was making all kinds of tones. lol. Driving the wife and kids crazy. Thanks for a great video. You should do more!
Thanks! I'm glad the video helped. When I'm teaching I like to use a function generator to test a room full of people to see who can hear the highest frequencies. I had one guy drop out after 8kHz. I wondered why he always seemed to be shouting. Anyway, glad the video was a help and there will definitely be more in the future.
I've seen lm386 circuits with seperate grounds for power and signal and also with caps on the input stage as well just wondered if you knew of this and could explain the theory behind this practice. 🤔regards Kevin
Hooked up a 555 timer with a flashing output installed the lm386 and got an ok sound but want it louder put in the cap on pin 8 and 1 but no difference even with the cap on pin 7. Any ideas ?
Hi i want to make this circuit for my little radio, to make it louder but i also want the bass function. what do i add or change in the circuit ot activate bass.
Excellent explanation! Not that I understood everything, but I find this very interesting. Is there a book or resource you would recommend for learning circuits. I’d really like to build a pedal. I’m thinking fuzz is probably one of the easier ones to do. Where would I start?
in almost all the other opamp vids I watched, they all use closed loop configuration. But in audio amps, they all seem to use lm386, and it's often open loop. Is there a difference between lm386 and your usual opamps?
I used the same circuit to build a audio amp and it produced a considerable noise ,to decrease it could I remove the potentiometer and just keep a 10k resistor ? And another question in case if we use the capacitor between the pin 1and 8 to inc the gain is it necessary to use the bypass capacitor at pin 7 ? why the decoupling capacitor is polar ?
+Amarnath Karthi Question #1: If you get rid of the potentiometer, how do you propose to use the 10k resistor? Will you connect it in series with the capacitor or bring the resistor to ground? Each will have a different effect. Neither will do a decent job of decrease the input levels like the potentiometer will. Question #2: It's not necessary to use the bypass capacitor, but when you start to hit higher gains by putting a capacitor between 1 and 8, you might need it. It helps to keep noise out of the earlier amplifier stages. It might help with your noise issue. Question #3: The decoupling capacitor is electrolytic. It's electrolytic because at a higher capacitor values, electrolytic capacitors are cheaper and reasonably sized. Because it's electrolytic, it will be polarity sensitive or polar. It doesn't have to be electrolytic. You could use something else however it might be larger than you want and cost more than you might want to pay.
10µF is a good value because it helps to short out those audio frequencies being produced by the amp. It doesn't need to be electrolytic but it's probably cheaper.
i enjoyed ur videos, plz do more vids of explaining weird schematics, also im getting the sound i want along with fuzzy noise, do u know hw do i get rid of that,
When I take out the potentiometer because I control the Volume with pins 1 and 8 by putting a potentiometer between them and the capacitor only using 2 pins of the potentiometer , can I just let out the potentiometer on pin 3 or do I need to add 1 or 2 resistors?
+aravind jayanthi Yes. The capacitor blocks any DC voltage that might be present on the output of an audio source. For instance, I use a lot of powered microphones. The capacitor blocks the DC voltage used to activate the microphone but allows the AC signal produced by the microphone to pass to the amplifier.
Thank you very much sir. Sir i want to know about the highest value of capacitor that we can use to increase gain between pin 1 n 8. Is it necessary to add a resistor in series with the capacitor? please specify values also.
+shubham kushwaha The datasheet recommends using a capacitor of 10µF. This will increase the amplifier gain to 200. Without the capacitor, the gain is 20. It is not necessary to add a resistor in series with this capacitor. If you do, you will decrease the gain.
Thanks, nice informative vid on a basic amp circuit bit of a refresher from school anyway, found you on G+ too btw, seems to be easier to find more interesting things than cat videos
+Nick Sebring No, you would not need the 10k resistor. The potentiometer in the circuit is just there to vary the input level of the audio. If you don't need that functionality, leave it out. I would keep the capacitor between the audio input and pin 3. Have a great day!
1.is there any reason for using polar capacitor for decoupling and also between potentiometer and pin 3? 2.in my project which involves the use this lm386 circuit we used with input as mobile phone and out with a speaker , in order to reduce the noise can we remove the potentiometer as we can control the signal power with the volume rocker ?
+Tatsuya Shiba 1. The only reason I'm using that capacitor is because it's easier to find electrolytic capacitors at that capacitance. Many times they are also cheaper and smaller than their ceramic counterparts.2. You can remove the potentiometer but I don't know if doing so will solve your noise issue. I would think keeping it can only help.
hey, great explaination! Thank You! Ive got a question about the formular, what is R ? (R1+R2 ?) in wiki there is it but instead of R there stands R2 (again) for . please explain it... I´m not that in... so maybe it is a stupid question... in case, sorry for that ! ;-)
I use this circuit with 12 volts but after 3-2 trials the chip burnt. I tried with 2 chips and both have same problem so what is issue with 12 volts. I am using 3*18650 cell as power
The 12V source should be fine, but I would make sure not other AC noise is coming across the 12V transformer. If that transformer is connected to mains power, you might end up fighting a pretty nasty 60Hz hum noise on the output.
For most LM386 chips, 12V is the high end of the voltage range. There are some chips that will accept more. As far as current, it shouldn't matter that much. Also, if you setup the circuit right, the speaker shouldn't be affected by the voltage because it is protected by a fairly large capacitor.
+Skinny R&D Let me put it another way. Can the sound from a 555 timer be increased . Currently I have pin 3 going to a resister then a transistor . I have the speaker hooked up to the transistor collector and ground . I would like to make it louder I was hoping an amp would do the trick but no luck with the lm386 hope this helps I will draw up a schematic and figure out where to put it if you still need one . Ps the sound is going off and on like a flashing led which is what I want so that part is good. Just not loud enough for what I want it for Regards
+RC Canuck Yes, the sound from the 555 Timer can be increased by using an amp, but it can only increase to the voltage level you are supplying. According to the datasheet if you use a 5V source, you will get an output high of 3.3V. Even if you put that through an lm386 with a 5V source, the highest output on the amplifier you can hope to get is just under 5V no matter the gain setting. You may need to power the amplifier with a higher voltage source and then put the speaker in the configuration shown in the upper left hand corner of page 5 of this this pdf: www.ti.com/lit/ds/symlink/lm386.pdf With all that said, I've not hooked a speaker up to the output of the 555 timer. I've only used ultrasonic speakers. Those work pretty well. Is the speaker you are using an 8Ω speaker. Let me know and I may try it for myself when I get a chance.
I'm aware this is an old video but that was the best explanation I've found of how the LM386 works.
Thanks and I hope you're doing well!
Seeing this circuit is one thing, but having the reason for peripheral components explained in a very clear manner is a total other ballgame. Thank you so much... wish I would have gotten into this when I was younger, but no time for regrets!
Thank you. I learned more in 12 minutes than would learn in an hour
thanks this was concise , simple and easy to understand as an intro to 386 amp chips is invaluable for me embarking on a new path at 66 years old.
I understood SO MUCH with your video than in any video I have watched. I'm serious! Thanks for your explanation of this circuit! You are really great teacher.
Great video, very informative. I've been playing with the 386 IC but was having trouble finding info explaining how it worked, this helped out a lot.
Such a good explanation on the lm386 and all the extra theory just the video i was looking for. Subbed, liked and keep up the great work :)
Well done ... an excellent and integrated explanation for this amp...
thank you very much
Excellent video. Wish I had found yours before the other dozen that I watched first. Subscribing now!
Amazing video even today. Thank you so much for your help!
Wow, 8 years late but super clear explanation....thanks
Neatly and logically explained the topic. Keep it up.i like your videos ver much.
Excellent Video, practical, real world, hands-on learning project! Brilliant work!
Thanks!
Good explanation of the concepts and application. Thanks for the video!
Thanks for watching!
As an Advanced avionics tech at Boeing for 30 years I saw a lot of engineers with book knowledge and no practical experience with real life application. It was our job to lead the engineers as what a circuit really did in real life circumstances compared to paper
Thank you. I learned more in 12 minutes than I have in the hour I spent poking around the web. The only thing I missed was why you added the 10uF cap between the audio source and pin 3. I assume it is used to prevent clipping or filter out AC voltage. Again, many thanks from an old guy trying to learn new tricks!
+Rick Schrager I'm glad the video was helpful. The cap is there to block any potential DC voltage from flowing into the input of the amp. It only allows AC voltage (the audio) to pass.
I'm late find this vid - I love the way you explained it
Great explanation of the Boucherot Cell!
Thank you, very good explanation!
I really enjoy your video’s, the explanation and practical uses of the circuitry. Sometimes I have a hard time following because I was thought electron current flow but you explain things from a conventional current flow, also known as (Hole Flow). I know either works but it’s still rather difficult seeing it explained in a different direction. Maybe you can share something that could help me?
Hey, great video. I took this information and built an amplifier using the LM386. As a source, I used my Siglent SDG805 function generator and was making all kinds of tones. lol. Driving the wife and kids crazy. Thanks for a great video. You should do more!
Thanks! I'm glad the video helped. When I'm teaching I like to use a function generator to test a room full of people to see who can hear the highest frequencies. I had one guy drop out after 8kHz. I wondered why he always seemed to be shouting. Anyway, glad the video was a help and there will definitely be more in the future.
Great explanation!
Excellent bro, I have learnt a lot ❤️why actually we have to use that capacitor and resistor in first place.. That u have explained at last
I've seen lm386 circuits with seperate grounds for power and signal and also with caps on the input stage as well just wondered if you knew of this and could explain the theory behind this practice. 🤔regards Kevin
what if i wanted to connect it to a arduino Id would need the half dc offset would i cut into the singnal before the big capacitor?
great information sir very useful for projects
+Vinay Bugade Thanks!
Hooked up a 555 timer with a flashing output installed the lm386 and got an ok sound but want it louder put in the cap on pin 8 and 1 but no difference even with the cap on pin 7. Any ideas ?
Thanks! This helped a lot.
Glad it could be of use :)
Hi i want to make this circuit for my little radio, to make it louder but i also want the bass function. what do i add or change in the circuit ot activate bass.
also what if u wanted ot add a low pass filter?
Excellent, thank you.
Excellent explanation! Not that I understood everything, but I find this very interesting. Is there a book or resource you would recommend for learning circuits. I’d really like to build a pedal. I’m thinking fuzz is probably one of the easier ones to do. Where would I start?
Dude you are awesome...
thanks man.
You're welcome!
in almost all the other opamp vids I watched, they all use closed loop configuration. But in audio amps, they all seem to use lm386, and it's often open loop. Is there a difference between lm386 and your usual opamps?
I want to connect 8ohm 10 watts speaker to it, will it work properly....?
I used the same circuit to build a audio amp and it produced a considerable noise ,to decrease it could I remove the potentiometer and just keep a 10k resistor ?
And another question in case if we use the capacitor between the pin 1and 8 to inc the gain is it necessary to use the bypass capacitor at pin 7 ?
why the decoupling capacitor is polar ?
+Amarnath Karthi Question #1: If you get rid of the potentiometer, how do you propose to use the 10k resistor? Will you connect it in series with the capacitor or bring the resistor to ground? Each will have a different effect. Neither will do a decent job of decrease the input levels like the potentiometer will.
Question #2: It's not necessary to use the bypass capacitor, but when you start to hit higher gains by putting a capacitor between 1 and 8, you might need it. It helps to keep noise out of the earlier amplifier stages. It might help with your noise issue.
Question #3: The decoupling capacitor is electrolytic. It's electrolytic because at a higher capacitor values, electrolytic capacitors are cheaper and reasonably sized. Because it's electrolytic, it will be polarity sensitive or polar. It doesn't have to be electrolytic. You could use something else however it might be larger than you want and cost more than you might want to pay.
well explained but i tried using 386 d to a small fm radio and sound is no louder??///
+skinny R&D how do i know if my lm386 is not defected??
Thank you for that decoupling cap trick :) Would it always be 10uF? It has to be electrolytic?
10µF is a good value because it helps to short out those audio frequencies being produced by the amp. It doesn't need to be electrolytic but it's probably cheaper.
i enjoyed ur videos, plz do more vids of explaining weird schematics, also im getting the sound i want along with fuzzy noise, do u know hw do i get rid of that,
Try putting a 10µF capacitor between pin 7 and ground.
When I take out the potentiometer because I control the Volume with pins 1 and 8 by putting a potentiometer between them and the capacitor only using 2 pins of the potentiometer , can I just let out the potentiometer on pin 3 or do I need to add 1 or 2 resistors?
I use 2 pins on the potentiometers all the time. It's just turns it into a simple variable resistor.
is there any reason for using capacitor between potentiometer and pin 3?
+aravind jayanthi Yes. The capacitor blocks any DC voltage that might be present on the output of an audio source. For instance, I use a lot of powered microphones. The capacitor blocks the DC voltage used to activate the microphone but allows the AC signal produced by the microphone to pass to the amplifier.
Thank you very much sir. Sir i want to know about the highest value of capacitor that we can use to increase gain between pin 1 n 8. Is it necessary to add a resistor in series with the capacitor?
please specify values also.
+shubham kushwaha The datasheet recommends using a capacitor of 10µF. This will increase the amplifier gain to 200. Without the capacitor, the gain is 20. It is not necessary to add a resistor in series with this capacitor. If you do, you will decrease the gain.
Thanks, nice informative vid on a basic amp circuit bit of a refresher from school anyway, found you on G+ too btw, seems to be easier to find more interesting things than cat videos
Dirt McGirt Your Welcome. I really like G+ for the communities. There always seems to be interesting people doing fun projects.
Just a quick question... If I took the potentiometer out of the equation, would I need a 10K resistor between audio input and pin 3?
+Nick Sebring No, you would not need the 10k resistor. The potentiometer in the circuit is just there to vary the input level of the audio. If you don't need that functionality, leave it out. I would keep the capacitor between the audio input and pin 3. Have a great day!
1.is there any reason for using polar capacitor for decoupling and also between potentiometer and pin 3?
2.in my project which involves the use this lm386 circuit we used with input as mobile phone and out with a speaker , in order to reduce the noise can we remove the potentiometer as we can control the signal power with the volume rocker ?
+Tatsuya Shiba 1. The only reason I'm using that capacitor is because it's easier to find electrolytic capacitors at that capacitance. Many times they are also cheaper and smaller than their ceramic counterparts.2. You can remove the potentiometer but I don't know if doing so will solve your noise issue. I would think keeping it can only help.
thanks for reply I After soldering the potentiometer connections the noise became less
I don't why I'd hadn't made the connection in my mind that a volume pot to ground is just a variable voltage divider before. Thanks!
Blew my mind when I found out.
hey, great explaination! Thank You! Ive got a question about the formular, what is R ? (R1+R2 ?) in wiki there is it but instead of R there stands R2 (again) for . please explain it... I´m not that in... so maybe it is a stupid question... in case, sorry for that ! ;-)
It should be Vs x (R2/(R1+R2)).
very nice!
Thanks!
I use this circuit with 12 volts but after 3-2 trials the chip burnt. I tried with 2 chips and both have same problem so what is issue with 12 volts. I am using 3*18650 cell as power
In the datasheet a normal LM386 should be able to handle 12V.
is the potensiometer a logarithmic or linear??
Any potentiometer used solely for volume should always be a logarithmic one. For gain, bass boost etc a linear one is better
The gain is not 20 dB and 200 dB but 20 and 200 (absolute). A gain of 200 dB would be an amplification factor 10 billions (10^10).
I would use with a source of 12v coming from a Transformer, the speaker will be 4ohm 5W...is it possible?
Great explanation
The 12V source should be fine, but I would make sure not other AC noise is coming across the 12V transformer. If that transformer is connected to mains power, you might end up fighting a pretty nasty 60Hz hum noise on the output.
@@Skinnyrd ok got it,then where should be connected if not to the main 230Vac? Maybe should be isolated?
I use batteries. Isolation will help. Try it without isolation first and see if it's a problem.
@@Skinnyrd Last but not least, i'm wondering about how many V/A my transformer should be to avoid any damage to the IC and speaker
For most LM386 chips, 12V is the high end of the voltage range. There are some chips that will accept more. As far as current, it shouldn't matter that much. Also, if you setup the circuit right, the speaker shouldn't be affected by the voltage because it is protected by a fairly large capacitor.
what would happen if i used a 15 ohm resistor instead of an 11 ohm one
It will work just as well.
I liked this video before you started bragging about your massive ground plane. Haha! JK, thanks man.
Oh ya only using 5 v dc. If that is a factor
+RC Canuck Maybe. No matter what your gain is, the audio could be limited by the 5V rail. If you can post a schematic somewhere, I can take a look.
+Skinny R&D
Let me put it another way. Can the sound from a 555 timer be increased . Currently I have pin 3 going to a resister then a transistor . I have the speaker hooked up to the transistor collector and ground . I would like to make it louder I was hoping an amp would do the trick but no luck with the lm386 hope this helps I will draw up a schematic and figure out where to put it if you still need one .
Ps the sound is going off and on like a flashing led which is what I want so that part is good. Just not loud enough for what I want it for
Regards
+RC Canuck Yes, the sound from the 555 Timer can be increased by using an amp, but it can only increase to the voltage level you are supplying. According to the datasheet if you use a 5V source, you will get an output high of 3.3V. Even if you put that through an lm386 with a 5V source, the highest output on the amplifier you can hope to get is just under 5V no matter the gain setting. You may need to power the amplifier with a higher voltage source and then put the speaker in the configuration shown in the upper left hand corner of page 5 of this this pdf: www.ti.com/lit/ds/symlink/lm386.pdf
With all that said, I've not hooked a speaker up to the output of the 555 timer. I've only used ultrasonic speakers. Those work pretty well. Is the speaker you are using an 8Ω speaker. Let me know and I may try it for myself when I get a chance.
First mod: increase input voltage to 12volts.
Depends on which usage for! For the use in a car - ok 12V - but for other mobile usage a 9V block is the way to go - in my opinion...