A neat little LM386 Audio Amplifier Kit for just $2 - so is it Bad or a Bargain?
ฝัง
- เผยแพร่เมื่อ 27 พ.ค. 2022
- This is a review of a very low-cost & compact LM386 audio amplifier kit that can be bought for just $2. Here we review & assemble the kit and test it with the outputs from both a personal radio O/P and MP3 player to see if it's an absolute bargain or just noisy rubbish.
Thanks for watching
TWCG
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Nice build! I building one now I want to use as a small battery power amplifier for my 3 string cigar box guitar. I connected the guitar Jack to the audio input, is that correct. I not getting any sound out of the speaker I connected the speaker to the SP +- on the PCB.
Thanks
Hi, that sounds a very interesting project. Your speaker connections to SP+ - are correct. If you not getting any O/P, you might want to re-check a few items:
1. Check the polarity of your DC supply connections if you are using the 3.5mm jack as it is easy to get these crossed.
2. Check that all the electrolytic capacitors are correctly connected polarity wise.
3. Check for any unintended solder bridges.
4. Check that the DIL socket is not fitted the opposite way round & hence, the LM38 chip may end up being fitted 180 deg. to what it should be.
5. Check for any dry solder joints
6. If still no joy, try another speaker.
I would be interested on how you get on. Thanks for getting touch.
TWCG
@@TheWobblyCameraGuy Tanks for the help. I will check out over the weekend and let you know how I make out. Would I connect the guitar jacks into the 3.5 audio block?
@@richardgianatasio9611 Hi, yes you can use the 3.5mm audio jack connector or if you want a more permanent connection, there are a couple of solder pins directly behind the audio socket. Good luck!
you probably need a pre-amp
The LM386 really needs a bypass capacitor connected to pin 7, I use 100uf to be safe. However since the audio amplifier is self powered with its own battery supply I guess for most applications it is safe. It is a terrible chip though. With most other audio chips the chip designers take account of the effect of the current draw on the power rails and how that would feedback into the chip. The designers of the LM386 weren't that sophisticated, lol.
Hi, appreciate your observations. I have seen different capacitor values specified for this bypass capacitor from 0.1 up to 100uF as you mention. However, the extreme low cost of the kit has to be taken into consideration so I think we can forgive them for trying to save a few cents on capacitor. Although battery operated, electrical ac noise can be picked up from nearby electronics so it's a good thought and even maybe even across the +V & 0V lines to assist in filtering with maybe a 100uF & and one of a few pF. The great thing with these very low cost kits is that you could purchase a few to experiment with!
@@TheWobblyCameraGuy Very true. If you live in a low cost country you can get a completed LM386 module for 50 cent US.
I am thinking of getting more into module based electronics. Anyway thanks for the comment and the videos.
@@congchuatocmay4837 Hi, wow that's really low cost! These kits are a fun and low cost way to explore electronics and are better for using standard size components rather than the surface mount type which are always challenging to solder! I have a couple of more kits that I intend to review so it will be interesting to see how they eventually perform. Good luck with your modules!
It WAS DESIGNED for low-Fi use
hello i recently build my own speaker using 2 small speaker and a car door speaker now i used the motherboard of the small speaker and the car door speaker cant go louder is this because of the lower voltage battery (3.7v) or because of the motherboard and would this help with that issue ?
Hi, thanks for getting in touch. Assuming the gain is at maximum, (i.e. 10uF cap between pins 1 & 8) then there are a couple of things to look at. I'm not sure how you have connected three speakers to the amp, but if these are in parallel, then their overall impedance may be too low for the amp, (it needs at least 4 ohms). Your 3.7V dc supply is a little low, (some data sheets for the LM386 give a minimum of 4Vdc. As you say, a higher voltage will improve the output power a little). Note that the LM386 amp provided in the kit is rated between 200 & 300mW depending upon voltage. You could substitute it for an LM386-N4 which has higher output of approx. 1Watt. Hope this helps and good luck with your speaker build.
@@TheWobblyCameraGuy honestly i dont know im 14 and got bored on a sunday and started doing random things and somehow it worked and yesterday i got a bigger battery but still with 3.7 volts because i was scared that it would overheat or something with higher vaults bc im pretty bad at elektricity stuff
@@zedvandevenne3875 Hi, thanks for getting back to me. You may have had a partial short somewhere or a bad connection? I would suggest that you look at all your solder joints, (maybe with a magnifying glass) to make sure they are good, (usually if the solder joint looks very dull it may indicate a bad solder connection and is worth re-doing the joint). Don't give up my friend, keep exploring, learning and making new things! 👍
@@TheWobblyCameraGuy hi there im back aigan so i wanted to buy a higher voltage battery for my speaker i built but i cant find any good batterys i wanted i good voltage one but i cant find it and i would want it in a decent shiping time and price do you have any suggestions ?
@@zedvandevenne3875 Hi, I'm always happy to try and help you my friend. If you are struggling to find a 9V 0r 12V battery, then you could consider using several 'AA' size batteries in series to obtain the desired voltage. If you purchase a 6 way AA battery holder and PP3 battery clip to connect to your amplifier, then 6 AA batteries will give you 9Vdc. If you want a higher voltage try an 8 way AA holder which will give you 12Vdc. Hope this helps 👍
I just soldered one together and it don't work I should know better than to by fake stuff
Hi, sorry to hear your little amp didn't work out. However, it would be worth checking a few things before you give up. These might sound a little basic, but I have done some of these myself on more than a few occasions! Firstly, ensure that electrolytic capacitors have been correctly fitted as they are polarised & so will not perform reversed. Is the LM386 fitted the correct way around, (and a check to see if a pin has been bent)? Suggest you also check for any dry joints, (sometimes component leads require a quick rub with fine wet and dry to remove oxidisation especially if new old stock items are used), solder bridges between PCB tracks etc. All worth checking - good luck!
skill issue
Can use this one in the car?
Hi, good question! It is possible, but in my opinion, not really recommended. It's maximum upper voltage supply is given as 12Vdc and car batteries & charging systems can go as high as 14Vdc depending upon load. Additionally the audio output would not really be loud enough. However, if you search for 'car audio amplifiers' in AliExpress, there are a lot of low cost $10 or less amplifiers that may be just what you are looking for. Good luck in finding your amp.
@@TheWobblyCameraGuy thanks
@@haythamso977 No problem, thank you for your interest.
No it’s against the law
@@tonywright8294 lmao