PAM8403 class D tiny stereo audio amplifier board review & test

I saw these on eBay and decided to give one a try. Rated 3 watts/ch into 4 ohms at 5v supply. Are these any good? Watch to see what I think of this postage stamp sized board.

[@JohnClulow]

Thanks so much for posting this, John. After watching your video, I picked up 5 of these off of ebay for like $4.76 incl shipping. It has most of the components shown on the PAM datasheet typical app, and I only added a 470 uF 10V cap on power per the datasheet. Just finished a build this morning putting it into a small polyethylene case that previously held two 18650's, added 2 RCA jacks for the speakers, a 3.5 mm jack for stereo audio input from my old Sandisk e280 V2 music player, and a shielded USB cable that gets connected to 5VDC boost regulated 4P 18650 pack I made. Using my 8 ohm Sony SS-B1000 bookend speakers, the sound is un-frickin' believable: Crystal clear with very nice treble and bass. It is so clean and clear I was stunned. I played several of my favorite album cuts and it was like hearing them for the first time. And what adds astonishment to amazement is that these were under a buck each and yet they are so good. Average power consumption appears to be only around 50 mA at the volumes I'm listening to in my little workbench area. Thanks again, this is a real gem.

[@geniz01]

I've used this amp for several small bluetooth projects. I have always been pleased. great to see it has your seal of approval

[@betlejuice247]

geniz01 do you ever use it with batteries if so what type are suggested?. I have 18650 batteries

[@jasejj]

The best part about these little amps us you can get them for about 50 cents on AliExpress... there is also a big brother to these which runs on 12v and puts out about 10w. Quite useful for bodge-repairing TVs and the like when the amp IC blows and you can't find a direct replacement.

[@czarzenana5125]

The 10W version is based on the PAM8610 There's also the PAM8406 which doubles the power from 5V power supply by allowing you to connect 2 Ohms speakers (or two 4 Ohms speakers parallel per channel). I tried this PAM8403 board with 2 Ohm speakers and it gets far too hot.

[@hananas2]

Good to know the 52 cent amp I ordered on AliExpress is gonna sound good 😜

[@hananas2]

Update: it sounds just like it's supposed to, no distortion or anything unless you turn it up too high like every amplifier

[@soyboy3274]

@@hananas2 down to ~12 to 17 cents now lol, there's also an almost equally as cheap 10w stereo amp for about 19 cents. Ridiculous when you think about it. The 2x10w one has some significant hiss tho...

[@hananas2]

@@soyboy3274 Depends if you get the version with a volume knob tho, I got the one with a volume knob on the board

[@EnvistiaMall]

Hi John, it's Ron from Envistia Mall. Thank you for the very informative review of our PAM8403 audio amplifier. I see that a number of the comments are asking about a higher power amplifier. I now carry the PAM8610 module, a 15W stereo amplifier that is very similar in design to this PAM8403. I would be happy to send you one for testing if you are interested. Feel free to message me through ebay, or through the Contact Us form on the Envistia Mall website, if you are interested.

[@JohnAudioTech]

Hi Ron, I sent you a message from your store.

[@asadulhuq]

Thanks for the excellent introduction to the PAM amplifier. I have added a similar board to amplify my wireless calling bell receiver sound. The calling bell originally produced a low volume of audio. Now with this amplifier the bell sound is sufficient.

[@hardtofind66]

That was an easy smooth Clear run through of the concepts I'm looking for. The big difference, for me were the well placed descriptions of - how you know it functions well, is it to specs, and things you change due to slightly newer variations of similar amps. As a Struggling beginner I feel like I learned some things from this video. Fun was had.

[@tectalabyss]

Hi John. Another cool review. When you said you had monetized your channel I turned off my ad blocker and refreshed the page. I clicked on all the ad's. I hope it helps your channel. Great work. All my best. Bobby

[@JohnAudioTech]

I used to hit the "skip ad" on most videos, but after watching Dave's video over on eevblog, I let them play. Now that I'm on the receiving end I know what it is like. Content providers deserve all they can get. I know my small channel will not earn much but hopefully enough to buy these amp boards and kits to make videos of.

[@TimoBirnschein]

Great video! Thank you for the measurements!

[@akratooos]

Can I connect to the output of this amp a power mosfet that switches 48v on and off to create a 100w amp?

[@mirceasabau5973]

With the same amp I could reach a RMS power of 4w in one channel and 3W RMS in both channel drive at full volume. The sound offered is extremely confident even at full volume with a low distorsion. Keep Up The Good Working ! And Happy New Year !

[@1970Landei]

I recently bough me this unit. It's cool for this size :)

[@Ender3Me]

I love these little amplifiers. They with for a ton of like projects.

[@vskhat]

Thank you for very useful review

[@drazenbobanac8070]

I want to use this board with only one speaker. What to do with other outputs to have the best sound?

[@drazenbobanac8070]

Hi John, I want to use thess board with only one speaker 5w 4ohm.What to do with other outputs to have the best sound? Thanks

[@adryanyork3581]

love your work, cheers

[@origoadam]

hi! could you tell me the values(including max wattage if possible) of the components in lpf filter? thanks in advance!

[@thelastmarble2464]

I got a little blue tooth speaker mp3 micro sd USB fm speaker, there was not two speakers as the original page said, but it sounded ok for about 3 months then it just stopped charging, I couldn't get the micro plug off and solder any leads for power, so I have been trying to find something I could use the single speaker with, the speaker does not have anything printed to say what it is, rather if it be 3 watt or 4 ohm. Nothing, so how would I figure that out with out a bunch of the equipment you have? And finally is there away you may be able to find to fix this problem with this little speaker? I did like it even if it was not spectaculer

[@DaniMutaqin]

What is the name of the noise filter that you are using, I'm experiencing the same thing

[@gopalakrishnang3966]

is it possible to give +5 v and audio input from usb port itself

[@E-BikingAdventures]

Those power readings you showed for an 4 ohm load at different voltages, will they be different with an 8 ohm load/speaker?

[@zaqsurany]

how can i connect them to the speakers and to the receiver at the same time?

[@MegaWayneD]

An excellent review! Been looking at these for my Gameboy Zero project, ordering some now.

[@JohnAudioTech]

Glad this helped. If they pickup noise, ad a 2.2k resistor across each input. Not a problem with the amp, they just have high impedance inputs.

[@MegaWayneD]

Thanks for that. The Raspberry Pi Zero's audio (PWM via the GPIO pins) isn't great anyway but any help it can get is a bonus!

[@amitghosh6966]

Can pam8403 be used as alternative to Lm386 or Tda2822 for better sound with less heat ? 2. Does it need heatsink if used for long time continuously playing music (say 5-6 hours) ?

[@daluamanoj]

I have created with this amplifier with Bluetooth module but finding some humming sound .Any solution ????

[@raymondheath7668]

I built one into a small box with two 1" rectangular speakers and a USB connector for power and a 3.5mm to plug into the audio out of computers for testing. Fits perfect in my computer tool box

[@mini4x4]

Hey John, I am interested ion buying the amps you made. How many do you have left

[@tallnrough68]

Please explain more about the output filter you put on that amp

[@Dr.Stein99]

Thanks for review. Did you check the power supply? My modules make the power dirty to anything else sharing power.

[@cadillacescalade5428]

Hi, Question for you, I bought a slew of these little amplifiers...but I see you have a compasiter on the power rail I'm using 1 for a Bluetooth project and I'm using a laptop speaker and I think it's a 3.5 battery lithium. but I was wanting to see how loud I could go with it ? I see you have a good sized speaker box an for the size of this board it sounds really good.

[@vivekvenkatsubramaniam437]

I am also trying to drive a 4 ohm speaker with this, off a 3.7V Li ion battery, but I'm experiencing severe grounding issues. The power and the ground channels get shorted whenever I try to play some music off my phone. Do I need to reduce my voltage? Or is this a connection issue? My connection is the same as yours. edit: I haven't used a filter in my connection.

[@matthewridgeway3985]

Hello John. I have a similar amp here, but what I want to use it for is a spring reverb driver for guitars. I want to have the guitar signal go into the right channel, then out of the right channel into the input port of the spring reverb tank. Then, on the output of the spring reverb tank, hook that up to the input of the left channel of the amplifier and then pass the output of the amplifier left channel into the guitar lead heading off to either the amplifier or the next pedal. Your thoughts on this idea would be a great help. Thank you.

[@granbull01]

Hi is this amplifier appropriate on 2 29ohm 50mW driver? (i do know it's a headphone speaker it's just that I am planning on making use of a bluetooth module with an output of 2.5mW. I'm just not sure if without an amplifier, the drivers could produce a good sound) Btw, the module i am planning on using is a blueinvent bcm-635-lc-8x. I'm asking because i'm not an engineer. I just want to diy this haha. Thanks for the reply.

[@barneymiller844]

Thank you john

[@tallnrough68]

Also, please get a TPA6120 headphone amp board (the red colored board) from eBay and test that. I love your videos, I wish I had your knowledge and equipment to be able to test some of my stuff I have. Keep up the good work !

[@21thTek]

Great ! does it pop when turn on ??

[@teknorian5503]

and i listen this video using pam8403 amplifier

[@moisestheentrepreneur637]

Hi which class A amplifier do you recommend ?? Class A is better sound quality right?

[@madjidhamdini8114]

very simple and cheap very easy to made ^^ i use this one to made an amplifier for my little sister (2.1) pam 8403 for stereo with small speakers and a couple of darlington tip 142/147 for the bass , it work fine :)

[@Friendroid]

Yes! I mentioned these in the past here, I was having trouble connecting them to a bluetooth module XS3868 (?) and ended up having to use 2 separate batteries.

[@geniz01]

if you are using one supply with a BIT module you have to use a DC-DC isolation module. like a Murata NMH0505SC

[@geniz01]

+geniz01 BT not BIT

[@_DSch]

There is an error in the design of the module, i also had the issue and solved it by soldering an cap between the antenna and ground.

[@njfulwider5]

If you have extra TP4056, you can connect 2 of them to one battery and use the protection part of the TP4056 just like an Isolation module? I have gotten this to work a few times. Not sure why it works, but i used this method one my last logetec rebuild video.

[@pascallanger]

Hi John, good videos as always. Question: If I feed the PAM8403 with a mono signal (same signal on Left and Right channels), can I connect together the outputs (OUTR+ with OUTL+ and OUTR- with OUTR-) to get a double power output on a single speaker?

[@JohnAudioTech]

If you have a low impedance speaker, say 2 ohms, you could try this. You would need a current sharing resistor on each output pin of .1 ohms (four total). If your speaker is 3 ohms or more, it won't help because one channel is capable of driving the load.

[@mrjohhhnnnyyy5797]

This amp is ideal for a small portable speaker, I made one with a 3W 4Ohm speaker being powered from a single 18650 Li-Ion cell. Has plenty of grunt for a little portable speaker and the battery lasts for a gooood amount of time.

[@madjidhamdini8114]

yes you're right ;) the consuption not exeed +/- 300ma and yes , with just a little battery li ion it's good

[@thelastmarble2464]

Ok so right after I posted a question of measuring the speaker or some how finding out what it is, I just happened to find out it is defiantly a 3watt 4ohm speaker, but now I need to know if there might be away to fix the thing or maybe the amp you review in this video will be ok to use with this little speaker, I know I will need another of the same size

[@budandbean1]

This is so great, thank you so much for the nice explanation. This is the first time I've found you but I will be subscribing. If you don't mind, how did you build your speaker test setup? Did you just use 4 ohm speakers or did you just set your crossover to 4 ohms? Thank you again. Buddy

[@JohnAudioTech]

The speakers I used are actually 8 ohm and made to be portable. 8 ohm speakers are fine provided they are sensitive enough. of course, 4 ohm loads were used in the power test. Thanks for subscribing!

[@rajivcybercafe9234]

Every vidio true thanks for nice information

[@ChongMcBong]

these amps are perfect for raspberry pi projects, they run nicely from usb power, and sound pretty good paired with some old, salvaged laptop speakers. perfect for tiny audio projects :)

[@FutzWith]

I have a Pam8403 Chip with a different board layout, (it is nice to have a volume), I use 8 ohm speakers it still sounds good and has plenty of volume. I recently added a Bluetooth/mps player. I ran 2 different Pam8403 based boards on a 3200mha Linthum battery it lasted about a week of multi hours a day.

[@veteran-gamer]

great video thanks....... i've just got a couple of these..... and am using it with a small usb sound card with 2 4ohm 1.5w speakers.... i keep getting a popping sound on powering on.... i would really appreciate any remedies or fix for this ( bit of a noob) thanks you

[@esbro69s]

Is two 4ohm, 2wate speaker perfect for this amplifier?😮

[@betlejuice247]

Thank you for the video

[@duckingtonedits2369]

Great video I’m building a portable wii and I think this would make a great amp for the onboard speakers

[@spaga668]

bro i can't get any bass from pam8403. tried 3 boards and they all lack sound volume and bass idk why

[@chopzuki]

John... I noticed while looking at the IC's datasheet and these boards that the IC's left and right (+) output pins are tied to the (-) output terminals on these boards. Wouldn't the output then be 180° out of phase ?

[@JohnAudioTech]

Usually, there is an output pin marked as + and -. Normally, you'd expect the - pin to be tied to ground, but these are bridged amplifiers with the - pin being the output of an amplifier that is 180 deg. out of phase from the + pin amplifier. This "bridging" of two amplifiers allows for much greater output power at a given supply voltage.

[@neojupyter322]

i am watching this video using PAM8403 😜. Sound quality is good enough under this price 😊

[@codebeat4192]

Great video, great impressive tiny amp module. Did you knew you can other things with these little wonders? Believe it or not but I use these cheap boards to drive resqued/salvaged VFDs (Vacuum Fluorescent Display) its filaments, works great! Mostly a filament wire is 6 to 8 ohms depending on the size of the display. An amplifier like this is a great tiny current source (at a low voltage) and is exactly what the electrons inside the display are looking for ;-) Its output (one channel) is AC instead of DC that avoids uneven brightness of the display and avoids damage of long term DC usage. It is also easy to drive because it needs only 5VDC and it provides a TTL-level (with use of some resistors) brightness control (if needed, if noise is not powerful enough) so you can input a wave (frequency or PWM (square)) to control the brightness. You can do this for example with a microcontroller/Arduino or another oscillating capable circuit. This tiny thing saves you the need to design a complicated coil, H-bridge, half bridge solution or special (mostly obsolete) driver IC to drive the filament of such displays and it is really cheap. I use this method in a few projects and it is really great. Nobody told me this possible in my journey to find an easy solution. Only want to let you (and others to know) that amplifiers can be used for other things that isn't described inside the manual. Try it if you like, it is great!

[@jarrodlangford7692]

Your comment gave me such a great idea man. Never looked into VFD, wow awesome concept!

[@michaelgasperik4319]

I know I'm pretty late jumping in here with questions but does anyone know how much current this board draws? I will be using USB power and two 4 ohm speakers, just trying to make sure 5v at 1 amp is enough to power it. I just bought 12 of these from Amazon for about $10.

[@JohnAudioTech]

You should be fine with 1 amp.

[@Ttagia]

How to add up Bluetooth module to this amplified?

[@samuelbarabe8243]

Hi ! I just discovered your channel searching about amp module for cosplay props. I have a few of these PAM8403 modules and I used to put some big capacitor on the input voltage, like 2 or 3300uF. I can't find a clear information about how big should be the capacitor, I've read somewhere 1000uF per watt... I've seen in your video that you're using quite small capacitor, like 220uF I think ? So my question is how do I select the rigth capacitor size for the input voltage ? Also, do you have a good reference book to recommand that might cover this subject ? I'm quite noob on amplifier and there is so much contradictory information on the web. Thank you !

[@JohnAudioTech]

It depends on your power supply. 1000uf would be plenty for this amp

[@samuelbarabe8243]

Ok I have a 8A dc-dc 6-14V to 5V power supply module CK1408. Is it better to have multiple capacitors like 1000uF, 220uF and 0.1uF to smooth the input voltage or just the 1000uF?

[@razaaejaz]

Can I use this to make a portable headphone amplifier, would that be of good use? I am planning to use 18650 batteries to power it

[@Acoustic_Theory]

This is a full-bridge Class D amplifier. It would not be suitable for a headphone amplifier because (a) most headphones use a common ground for left and right ears (if you tie the negative outputs of this amp together it will burn up almost instantly), and (b) as as Class-D amplifier, it has switching noise, but because it has no output filter it uses the coil of the speaker as its low-pass filter, so the speaker will radiate much more electromagnetic field into the head of the wearer, which could cause an increased risk of brain cancer over time. This amplifier doesn't cause cancer, but long term exposure to high strength electromagnetic fields from any source can damage the DNA of brain cells and cause them to become cancerous, and using this amplifier to power headphone drivers very close to your head could increase that risk.

[@ntoobe]

John, Would this be adequate as a headphones amplifier? Nothing fancy, just ordinary small earbuds or the like.

[@JohnAudioTech]

Probably not because it is a bridged amp and the wires on most ordinary phones like earbuds have the common lead tied together. Consider the output leads on any bridge amp as hot and never tie them to ground or to another channel as this will short the amp.

[@seans1102]

i have one of these and I was thinking of running it at 2.5 volts hooked up to one of my maxwell 300 farad super caps. I dont know electronics but would this mess anything up?

[@JohnAudioTech]

2.5v is already at the minimum operating voltage. The amp will shut down as the capacitor voltage drops, so run time will be short. With two super caps in series for 5v would be the better way to go.

[@iceberg789]

someone also said it gives out some em radiation at outputs. how did it sound with o/p filters ?

[@JohnAudioTech]

I didn't try as my filter rolled off the highs. A proper filter should sound fine.

[@MyBigThing2010]

can you add a pot somehow to physically control the volume? how would be the best way to go about that? I have two sitting here but I don't wanna blow up the chip or have to solder on new SMD passives if I can help it. sorry if this seems like a stupid question...I'm a Newb to messing with audio electronics

[@JohnAudioTech]

Yes you can. I covered it here: kzbin.info/www/bejne/jpakn35qbqeoZ9U

[@MyBigThing2010]

JohnAudioTech awesome! THANK YOU!

[@BBXFX]

MyBigThing2010 I was searching all the questions for exactly the same thing adding a volume knob to this board period and thanks to John for providing a video covering this subject

[@DanubioRodriguez]

Can I use PAM8403 as preamp to input for TDA7377 amp?

[@DanubioRodriguez]

TDA7377 the input signal do not have high gain

[@Mezmorize99]

Wish you would have tested at 5.5v the pdf from the chip makes recommends that voltage (and 6.0v is maximum). Nice video, have ordered a few of these, waiting for their arrival.

[@terencekaye9948]

Hi John,, Thanks for the great video,, I have a question or 3,, Would these work using 5 volt USB power (say from a Lap Top ) and if I wanted to add volume controls to the inputs of this amplifier what size pots would be needed..Thank you,,

[@JohnAudioTech]

Yes they can work with 5v USB power. You might confirm that your laptop's USB port can handle 500ma or more of current. 10K pot would work. You can use a lower resistance pot if signal is coming from a headphone output (less noise).

[@terencekaye9948]

Thanks John,,

[@raindogred]

that sounds cool. thinking about using one to make little electric guitar amp. I realise I need some kind of preamp to impedance match signal from an electric guitar. typically the input resistor for a guitar amp is somehwere between 500k-!Mohm. Theres lots of little jfet preamp schematics, or simple opamp designs floating around on the web. I like the idea that this is stereo, and would like to use both channels. I think it might sound nice for certain effects pedals that bounce the signal across stereo field. I'm confused about how you would take mono signal and have it to go through both channels. Is some kind of basic mixer circuit required??? Any thoughts appreciated..????

[@JohnAudioTech]

When using my function generator in the video, I simply tied the inputs together to feed both channels. To work with both stereo and mono FX boxes you'd need a mixer.

[@prantaprotimchakrabarty9049]

Can I use a AV connector which has a common output ground to connect speakers?

[@modelnutty6503]

nope!

[@Djamboo]

So if its 3w and 5v and for current we have I(A) = P(W) / V(V) so I = 3 / 5... It works on 0.6A or 600mAh? Or is it 1.2A or 1200mAh because it have dual channel?

[@JohnAudioTech]

At maximum clean power it was 1.7 watts per channel, so 3.4 w for two channels. I'd add about 10% more to that because the amplifier is around 90% efficient, so I'd say 3.7 watts for roughly 750ma @ 5v. Pushing it into clipping can cause a higher power draw. Normal music does not present such a continuous signal, so power would be well under 100ma for normal listening levels.

[@Yefatbastard]

FYI I just bought 3 of these from Banggood, according to them, this is suppose to put out 3 watts per channel at 5 volts with 4 Ohm load. Link ----> www.banggood.com/3Pcs-PAM8403-Mini-Digital-Power-Amplifier-Board-Class-D-Audio-Module-p-943578.html Did you happen to notice if the chip got hot at all? Thanks..

[@Patata0ke]

this amp is also used by SoundGear pc speakers and it sounds very clean with no distortion at all. I'm very impressed compared to the Genius pc speaker

[@benlorenz2010]

Trying to read the output across a 4 ohm speaker, this amp seems to be clipping as soon as I connect ground from a probe. How do I read the output signal? Thanks

[@JohnAudioTech]

It could be possible you are shorting the output with the grounded probe if the power supply or signal source is grounded as well.

[@benlorenz2010]

@@JohnAudioTech thank you. You are correct. Both are grounded. How could I read both source and amplifier output at the same time then?

[@ebiscaia]

Any plans of using a Korg Nutube?

[@Synthematix]

I used this little amp (the version with the volume pot onboard) with a pair of cambridge soundworks 1.25" speakers out of a creative travelmate, i built a box out of modellers plastic (styrene) that can be glued with polystyrene cement, fitted a pair of mini bass tubes out of styrene tubing porting out of the back (20mm wide tube), it's in the front of my antec P100 PC case on a socket 754 PC with an athlon64 3700+ CPU and Radeon9800 Pro graphics card (Motherboard is an ASUS K8V SE Deluxe) Its routed internally to my Soundblaster live 5.1 card running windows98SE, i also fitted a separate '3rd' speaker going directly to the soundblasters 'PC Speaker' output with a 100Ohm potentiometer this is for DOS sound (to control the bios beep volume level and DOS gaming/music sounds), i tell you what the sound quality from this little thing in my front drive bay is just incredible, it's real crisp and has a surprising amount of bass for a drive bay speaker, i cant recommend these things highly enough, they are incredible!

[@kougaz]

what are the values of the capacitor and the choke that you used to get rid of noise?

[@JohnAudioTech]

680mH and .1 uf, IIRC. It was for measuring only. Not needed for normal use. Those values would cut into the audio band. I just grabbed what I had.

[@A_a_ron_4_RC]

I'm trying to make a horn for my RC Vehicles and I think this'll work. I've got a sound chip from a old toy with a dixie horn sound. I just need to up the sound loudness I think this'll do. So far I've been getting a stuttering sound even with a capacitor for the power.

[@rajivbadan7874]

Sir I like every video nice information nice explain sir explan stk japan ic all series

[@cenko.3381]

Hi, thanks for the video, I bought two of them PAM 8403 the red board and green one with the pot. But both of them they are strangly low power and distortion even at small speakers. Where I am making mistakes ? I drive them 5v 1A phone charger or adapter but really very low voice, crackes and distortion ! I bought them from Aliexpress and I start to think that may be chips are fake. What you think ?

[@JohnAudioTech]

Be sure the speakers are connected across the output terminals (not output to ground) since this is a bridge type amplifier. You could also add a 1k resistor across each input to shunt away any possible noise the amp picks up (sometimes causes distortion to the sound).

[@terencekaye9948]

Hi John,, It's 5 volts, I'm wondering what ma rating is needed from the power supply,,? Thanks.

[@JohnAudioTech]

700 ma at max clean power. Probably only 100-200 ma at normal listening volume.

[@poptartmcjelly7054]

Would be fun to see if you can add mosfets to boost the output stage

[@drazenbobanac8070]

I bought this Micro USB 5V PAM8403 Bluetooth Digital Audio Receiver Stereo Amplifier Board Is it better to connect with booster step up 5V module or directly from the 18650 battery? Thanks!

[@JohnAudioTech]

Running the amplifier from 5v will get you more power.

[@drazenbobanac8070]

@@JohnAudioTech Thanks, What do you recommend dor step up V?

[@toraseko4300]

I've used another bluetooth module. 'Cause you said the other one had differential outputs. I hook it up to the same battery. There was some "data" noise but once I've added the 3v to 5v converter. The noise was gone. But its making another noise again. I think its from the converter. Its not noticable at high volumes but its really noticible when the music is quiet. Its sort of like little popping noises. What should I do?

[@toraseko4300]

I've added a 1000uf capacitor to the output of the boost converter. The noise is in a different interval now.

[@toraseko4300]

drive.google.com/file/d/0Bw6N8kFthuWmQWlNd3JZYWV3Slk/view?usp=drivesdk It sounds like this.

[@toraseko4300]

Help. I'm having trouble connecting it to my bluetooth module (I got it from a bluetooth stereo headset). The bluetooth module has two grounds. One for the left channel. One for the right channel. If I connect them together, the audio output is terrible. Its really weird. How do I hook it up to this amp with just one ground on stereo?

[@toraseko4300]

And there's also a weird data noise if I put it on mono only.

[@JohnAudioTech]

Not sure but it sounds like the BT module has differential outputs. You could try connecting the ground side to the module through 1k resistors (one resistor for each channel).

[@toraseko4300]

Oh...So I can't use stereo?

[@Dad-ij2qy]

Thank you for reviewing this miniature amp. I know you don't have a full-fledged frequency response analyzer. But would you please do order-of-magnitude THD estimation ? Is it 0.1% or 1% or 10% with the frequency plot on your o'scope? I'm guessing you just look at the largest harmonic and take the ratio between number of squares of the largest harmonic divided by number of squares of the fundamental tone. Could you do this at 10kHz as well as 1 kHz ?

[@mrmshifan]

Hi, I have a question for you. How is it possible for an amplifier to output 100W of power by consuming 60W? Am I missing something? I only joined the channel recently after seeing one of the videos about lowering the input noise. Looking forward to watch other interested videos as well. Thank you.

[@JohnAudioTech]

If an amplifier is putting out 100w it will be consuming more than 100w otherwise it would be breaking the laws of thermal dynamics.

[@mrmshifan]

@@JohnAudioTech Hello John, Thank you for the reply :) I see some people selling amplifiers that output 100w, 200w 300w. Tuk tuk (three wheeler) users in my country (Sri Lanka ) have these installed in them. The only power source is the vehicles battery. So that's why I wanted to know if I was missing something. Thank you :)

[@MrQuatale]

Hey John, can I also use this litle amp to pre amp any Turntableplayer to connect on a receiver without phono input?

[@senorverde09]

Certainly you'll need something that follows an RIAA curve right?

[@MrQuatale]

@@senorverde09 yes. I recognized that some cheap riaa amps use only one op in the circuit instead of two. Must be important , as i recognized that the ground between left and right output of my turntable are separated. Can you recommend a china preamp board on aliexpress?

[@darrenpinto3055]

So this amp has 3w rms/channel, so is it better to use 3w speakers or 5w speakers. Also what would be the difference in performance

[@JohnAudioTech]

You could use either speaker. Just use the ones that give you better sound.

[@darrenpinto3055]

JohnAudioTech ok thanks

[@yulinubi1277]

If you play more than half volume ,the bass start down isn't it?

[@jainvibhore1997]

I was waiting for this one since last year :P. If you liked PAM8403 you might love its big brother PAM8610. I bought it hooked it to a crap 10 watt speaker and guess what my speaker blew and the chip was barely warm.

[@JohnAudioTech]

I'll have to check that one out.

[@paulb4uk]

These little amps are great for the price

[@vedurj9723]

Hey John I just buy a pam8403 but I don't have a CRO or DSO so could you just tell me the values of the components used for output filter.. cause I wanted to connect a Bluetooth module with the tiny amp but ended up with lots of hum,, hiss,, and distortion..that will help me a lot by the way your stuff is amazing I watch your all videos and try to learn something new ..

[@vedurj9723]

How to get more bass in this amp in 3watt × 2 speakers

[@englishrupe01]

I have seen one guy rigged three of these on top of one another to get great bass! I just ordered ten of these for $1.81 off AliExpress and might try that!

[@molozakos4084]

frequency responce range my frend?? it is like the normal ? namely 20HZ TO 20 KHZ? AND HOW MUCH AUDIO AMPL. OY PUT GIVES TO THE SPEKEARS? ? OR TO MY PROJECT TO THE FG -100 DDS SIGNAL DDS GENERATOR. TO HAVE STORGEST OUTPUT SINE --SQUARE -OUT PUT ????? THANKOU FROM GRECIA THESSALONIKI

[@qutiyagiry3087]

Does it have inbuilt Bluetooth or I have to buy external Bluetooth receiver

[@varunchhibber9778]

External

[@jj74qformerlyjailbreak3]

I removed the chip from one of these modules. I want to open up the Standby and Mute lines by cutting the traces.

[@jedijohnjohn8663]

Is it possible to add a volume control to this little board? If so... How?? Thank you for any help.

[@JohnAudioTech]

Yes, you can add an external control to the inputs. 10K audio taper stereo potentiometer would work.

[@jedijohnjohn8663]

Cool... and Thank you very much. I found 1 audio taper out of an old boombox but max R is 200 ohms... getting Some volume control on it. I want to use a power bank to power the chip... BUT a 10 sec auto shut off always trips off... especially between songs or quite moments in the music. I am using a USB Cable, just the black and red wire (green and white NULL). Is there a way to trick the system into detecting current draw such as a power indicator LED? I assume being a Class D amp... current draw drops during rest in music or song changes... thus auto shut off of power bank.

[@SimpleEnough2k9]

At first glance it looks like your power bank needs to draw some current to stay "alive". I would have thought that the 23ma @5v quiescent current would have been enough, but I guess not. The only thing I can think of would be to add a resistor in parallel with your Vin on the board such that it would allow to draw the extra milliamps necessary to keep the bank active. Be careful not to put something too low otherwise it could get warm and/or drain the bank too quickly. Also, validate that this is what is required to keep your power bank awake by testing the bank with other accessories.

[@jbx907]

looks like the amps in my bose bluetooth dual speakers

[@larryshaver3568]

beautiful sound,what is that music

[@williambragg6890]

has any one had a good play with the pam8406. how far off its datasheet is it. one thing I'm planning it taking a SRNWU Bluetooth module that runs with a pam8403 replacing it with a xx06 pull mode high and see if we get any more watts + there so cheap y the hell not

[@granbull01]

William Bragg can i get an update there? I just want to diy a bluetooth headset haha I'm planning on using a blueinvent bcm-635-lc-8x

[@williambragg6890]

It's not got far. Iv been playing with a CJMCU-8406 PAM8406 a small board with jumper to set the modes. just waiting on some 5w 2ohm speaker and Looking in to a 5v 4amp booster as the ones I use for the pam8403 are just 2amp. Then il get on to building something. Thinking I need to send one of there's amps to John for mail bag to test. Thay look good quality little things

[@bunsoft2]

nice vid :-)