LM3886 stereo amplifier board test and review

[@joeyscott4299]

I hope your doing well John . Love you channel ! One of a handful of channels I give a thumbs up to before the opening add finishes playing .

[@ugott1]

A comparison with the TDA7294 should be interesting.

[@Gratefulwon]

Why not unwrap it before displaying it...?

[@josephlalock8378]

no kidding. i had to jump ahead cuz the plastic wrap noise was irritating af

[@1959Berre]

@@josephlalock8378 Same here. That crackling noise in headphones hurts like hell.

[@publicmail2]

@@1959Berre I actually may have suffered pain and suffering and filed a complaint with youtube, the BBB, and WHO.

[@jimcole6423]

Maybe because its a product showcasing? Hmmmm?

[@tuhinadribanerjee3214]

Hands down, one of the best top few audio ics from TI.

[@bugdrvr]

The IC seemed to have performed very well. I'd like to see it on a properly designed board.

[@mysock351C]

@@bugdrvr I used them in my DIY build amplifier with a bipolar switchmode power supply I designed as well (form factor was too small for a standard mains transformer). They work very well and don't have any real noticeable hiss, which is a bonus. The only downside is they require a positive and negative supply unlike a bridged class-D since they are basically an oversized op-amp, which can make things a little more challenging. Had a hard time finding an off-the-shelf SMPS transformer that would work for my application. Luckily I was able to find one from Wurth that could be repurposed.

[@nitescuvalentin6872]

this one and the LM 4780.

[@byrnemcneill]

Great video, my dude. Planning an amp build using LM3886 chip amps, so it’s good to see that even a poor design/implementation still gives more than decent results. Thanks for confirming the choice of chip for me. Keep ‘em coming, mate.

[@Mr_Meowingtons]

cut open them caps see if they stuffed fake/counterfeit ones in there..

[@19janiboy96]

Wimas are beging faked aswell sadly

[@bugdrvr]

I'm dying to know what's rattling around in there!

[@VIPINSAINI_20]

I waited so long for this review thank 😄😄you

[@mysock351C]

I spotted something even more egregious, potentially. They left the output relay off the board, so if there is compensation in the feedback network for eliminating the DC offset (which it appears there is), it will have serious turn-on thump issues while its charging the caps in the feedback network.

[@rocketpoolpki]

That was an awesome upload, really well explained, nice one.

[@nikiforosf4824]

Why do you a pre-amplifier? Does it give any added value to this type of amplifiers ? Thanks for the video!

[@vizkoze]

It would make a nice video trying to fix the stability problem. Nice work explaining all this stuff.

[@JohnAudioTech]

stay tuned for that!

[@ksrele]

Is this chip better then TDA7294[V]? Did you test TDA7294 amp chip?

[@mukeshkumarsagar3840]

I love lm3886, sometime I forget even my girlfriend 😆

[@johncoops6897]

That's because the LM3886 gets hot when it makes a lot of noise.

[@acharyaguy]

Is it suitable for making bluetooth audio system and pls suggest good speaker setup for it ...

[@ergindemir7366]

There is probably a 25V or 35V 10mF capacitor inside that package. If you had tested it with a proper transformer it would blow up immediately.

[@Helectronics]

Thank you for making quality videos, you inspired me to do electronics videos. Keep up this good work!

[@swarajbiswas3056]

Hi John. Hope you and your cat are OK. I have tried your LM3886 circuit. Seems to work fine. I have 2 questions. First is, can we use a resistance type inductor instead of coil inductor at the output ? And second is, the circuit is working but sound is very faint. Iam using 21-0-21 volts supply. Is more voltage required for high power output ? Datasheet suggests 28 volts or higher but just a difference of 8 volts is decreasing the sound this much ?

[@JohnAudioTech]

What do you mean by a "resistance type inductor"? Sound should not be faint at 21-0-21 volts supply. Check input signal level.

[@swarajbiswas3056]

Resistance type inductor means the inductor looks like resistance. The body of inductor is like a fixed resistor and it has colour bands on it.

[@giovannicirlincione951]

Very cool review!!! I want to see the tda7294 too

[@Lithium09]

I'm into a lot of DIY audio amp stuff. But now i want to buy some good quality speakers. I'm buying them for my personal use and intent to use them for long time with good amplifier circuit. Please suggest me should i spend my money for 8 ohm speakers or 4 ohm speakers. Which is better? I know there's no definite answer for this but for which impedance would you spend your money? (Thinking of spending a little too much than usual) Please reply soon.

[@pliedtka]

I do some diy home spkr. With 4ohms woofer you will usually get 2-2.5dB higher out at the same voltage comparing to 8ohm version of the same driver. Other than that Thiele-Small parameters will be a little different, Qes, Qts being usually lower for 4ohm. The coil inductance higher in 8 ohm and will limit upper freq resp. unless it uses Faraday rings in the motor. If you're building own X-overs, the hardest part that requires measurement set up and CAD program for designing proper crossover, inductor sizes for 4ohm woofers will be smaller and caps higher. Of course 8 ohm is easier to drive if something like 3886 is used, but unless you have something with 90dB+ efficiency the volume may not be satisfying (there's usually a 5-6dB drop in low mids, bass so correction for baffle diffraction is used in x-o). Rather than using passive crossovers, DSP based crossovers with multiple amps are really awesome since many of passive crossover limitations don't exist in DSP that have EQ, time alignment, variable slopes capability. Designing a really good passive X-over is a pain.

[@bugdrvr]

As said above, you will get a bit higher DB out with lower ohm speakers but also need to make sure your amplifier can happily drive them. My B&Ws drop into the mid 3 ohms at some frequencies and you can definitely hear the stress on some amplifiers with a lack of bass and shouty, bad sounding mid range. Give them good clean power and they sound amazing. I'm a big B&W fan and always suggest checking them out but everyone is different so I'd suggest listening to as many different speakers you can before making a choice. Not easy these days without too many hi-fi shops around and even harder with the virus keeping everyone away from each other but it's worth it.

[@and1424]

Please use Siglent for thd as well! Just change the samples per second... Thanks for the video

[@remarpc]

It would be interesting to see how it would perform when a bypass cap is installed between VCC and ground right on the chip and a thiele circuit on the outputs

[@JohnAudioTech]

I plan to try to fix the issues.

[@gkdresden]

I would like to know what the preamplifiers opamps do in this circuit. What is the circuit around them telling us? I think it it easy to operate the LM3886 directly from music player or line level outputs.

[@sean-mayorga]

You convinced me to buy one of these and hear for myself. Its probably too late since that cap is cut open but I would love to see a video of you addressing the atrocious hum from an AC power input like a 25-0-25 transformer. I think the power supply needs rebuilding

[@christopherkise]

I like these lm3886 amps, would you care for making a ultimate version, in your view? I can draw the circuit board?

[@JohnAudioTech]

Visit Neurochrome audio.com. These are the best designed and boards and circuit available. They aren't cheap, but that's what quality costs.

[@VIPINSAINI_20]

@@JohnAudioTech Website Audio.com is dead,

[@christopherkise]

@@VIPINSAINI_20 neurochrome.com

[@christopherkise]

@@JohnAudioTech Thanks, I did not know about this site. 35 usd for a complete PCB job is not bad at all. Have you reviewed some of these boards?

[@IncreasingVoltage]

That one dislike must be from snickers being woken up ;)

[@acharyaguy]

Can I build bluetooth audio system with this chip ? What would be good speaker for this ? How much watts of midrange speakers and tweeters?

[@brunobassi2440]

50% woofer 30% midrange 20% tweeter .... This is a good starting point

[@RAVICHANDRAN-tt1yu]

Nice sir I want board with out power supply wher will get

[@hflorin07]

Siglent has a better FFT... Why don't you use it when checking THD?

[@davidjones9730]

Another great review. I too would like to see inside those caps but also wondered, just out of curiosity, would it be possible to add the improvements you suggested? I'm guessing a decoupling cap near the LM3886 would be easy to add what about the network you mentioned on the output? Perhaps it isn't worth the effort for this amp. Thanks again for the great channel.

[@mysock351C]

Its really only needed as at higher frequencies with the falling 6dB/decade response the amplifier looks inductive at its output, so if there is significant capacitance it can oscillate. With that said, I found these to be extremely sensitive to oscillations and RF interference if the layout is not done well. I kept the layout fairly minimalist with just resistors and RF/decoupling caps to avoid needing a relay on the output, but did include the inductor/resistor on the output side, just in case.

[@photorolensoman8101]

Can I bridge this amp in parallel and use 2 of this for bigger power?

[@kirankesav7608]

Hey john, Based on your experience, among lm3886 and tda7294, which gives better bass response and overall better music dynamic. Its ok if its bit colored sound also.

[@JohnAudioTech]

Given the flat frequency response and low distortion, I don't expect much difference in sound between the chips.

[@anthonynowlan9765]

3.30 = cap and resitor is zobel network?

[@RafaelVillalta-ui6rk]

for this kind of Amplifier you can use a red of zobel or even a speaker protection, I guess, cause the diagram to certain point I think it's good, that's my opinion right, great video dude

[@MrMaxeemum]

I'd be interested in hearing about the Thiel Network after a quick look I can't find any info on it, maybe not searching for the correct term.

[@JohnAudioTech]

The coil has higher impedance at high frequencies (well beyond audio range) which prevents the amplifier from driving capacitive loads at high frequencies. That can cause instability. Because the coil and capacitance will have resonance, a resistor is connected across the coil to reduce the Q of the circuit.

[@barneylinet6602]

Sometimes i think we have reached the end of the road for analog electronics.....Switching amps (class D) seems to be the trend. As a matter of fact, anything you can do with analog electronics can be done with switching circuitry. Having said that, the LM 3886 is going to be the classic solution for analog amplifiers....Some people prefer them for low distortion audio. Kind of like Compact Discs versus 33 rpm vinyl records.

[@wackenroader]

Class G/K Is evolving

[@sarbart823]

I would love to know how you would build a Bookshelf Wifi Active Speaker set

[@ao6640]

What about a single supply chips review/test series?

[@TBL_stevennelson]

I wonder if there's a nice board made for 4 Ohm Subwoofers. Couple it with a nice 3116 board for Mids and High's I could Make a nice little inexpensive sound system that uses low power but has a big impact

[@tenlittleindians]

Are your numbers in peak to peak or RMS? For us guitar players; can something like this function as a guitar amplifier? Could we feed the guitar signal into one channel of this amplifier and use it as a boost to get us to proper input levels for the other channel and end up with a mono instrument amplifier with about half the output wattage? For many of us this would be plenty of watts for a practice amp and we don't need full frequency response given the range of our instruments. It would be cheap guts for homebuilt project.

[@1pcfred]

Instrument amplifiers are different than reproduction amplifiers. There's more to it than just output Watts. I think it is down to the bias? An amp made for playing music is just too neutral. So they tend to lack presence and sound very thin. An instrument amp just has a richer more direct sound to it. Like you're actually there playing. Playing through a stereo it sounds like you're channeling a ghost. John should feature some musical amplifiers to tell us what the secret sauce in them is. But I guess that's not his thing?

[@tenlittleindians]

@@1pcfred It's called impedance balancing. The simplistic version of a device that does this is a transformer. I have one I use for a microphone to switch from low to high impedance and vise versa. Older record players needed help to get their small signal heard by an amplifier. The record arm pickup outputs about the same as a guitar pickup.

[@1pcfred]

@@tenlittleindians was a while ago I tried it. Back when phono inputs were popular.

[@tenlittleindians]

@@1pcfred I made an adapter to plug my guitar into the phono input of a stereo back in the 80's. It worked but it's clean sounding without some pedals in the signal chain.

[@1pcfred]

@@tenlittleindians clean is definitely one way I'd characterize the sound. A bit too clean. It is one of those works but it doesn't deals as far as I'm concerned. Tone is pretty important to a lot of players and one thing stereos don't give you is any tone whatsoever. Any stereo that did add color would get laughed out of the market. So they're designed to not do that. Maybe an old tube amp would be OK? Those are naturally "warm". There's no way around it really. The tube sound is real. I hear some early transistor circuit topographies were pretty bad. They were basically making tube amp circuits and using transistors. There's reasons solid state had a bad rap. Early transistors were pretty bad by themselves. But all of that changed over time. I've made some transistor amps that I think have nice tone. I biased the circuits hard to get it. Made them hot. Not hi-fi at all. More like hi-db Made to play loud at low volume. Had nice feedback. I got a little Marshall amp too and I like mine better. www.instructables.com/id/Transistor-Amplifier-Build/

[@manojkundel287]

Sir I want this board. where to get

[@Atelierul29]

Those caps have another smaller ones in them!

[@johnmoor8839]

lead free solder?

[@peteb2]

Yay the Gainclone. Had a couple of new Dynaudio Pro studio monitor active speakers being used in an onair sound suite part of a TV News production facility that would randomly suddenly motorboat at full volume.... Caused utter hell live... Anyway they're a warranty job but on account the rohna i replaced the three LM3886 set with GENUINE chips from Digikey. The problem solved. The chips i pulled out had bad smudged labels compared to the clean sharp replacements from DigiKey... Fake chips for sure....

[@shean-koklim4197]

Fantabulous, thanks!

[@helidupabasara1282]

Thank you very very much Sir !!!Sir can you please do a review of TDA 7498 & also I suggest you sir to do a comparison video series about audio qality, true maximum rms etc. TDA AB class vs TDA D class amplifiers (ex - TDA 7295 vs TDA 7498) Again thank you very Sir !!!I got a great knowledge about audio amplifiers through your attractive explanations included videos !!!

[@wackenroader]

Hard to compare, Class D is for energy efficiency, not for sound quality. Comparing class D with AB is like comparing MP3 with FLAC

[@jdsound4931]

Sir how to buy this amp?? I am from india

[@carlosgclimaco2754]

That moment when you shake the capacitor and confirm the videos showing big Chinese caps scam are real. :v

[@amitghosh6966]

If I use lower operating voltage like 12 Volts, will it draw more current from power supply (transformer) ?

[@johncoops6897]

No, it will draw less current

[@amitghosh6966]

@@johncoops6897 will an audio amplifier output the same power when a music is played as it is outputting when a 1 Khz sine wave is played ?

[@johncoops6897]

@@amitghosh6966 - I am having problems with my internet connection and have lost TWO detailed replies to your question. In summary, the answer depends on the power supply's current capabilities and also whether it is regulated (eg: electronic) or unregulated (transformer based). Power equals Volts SQUARED divided by Ohms... so a bit more voltage provides a LOT more power! On a regulated (electronic) power supply of sufficient power, the peak voltage for music and sine wave will be the same. Therefore (max) power output will be the same for both. On a more realistic regulated power supply with less power, there won't be enough current for continuous sine wave, so voltage will droop under continuous sine wave. Yet the big power capacitors will store enough amps to allow max power on music peaks. Therefore, "peak music power" will be higher than continuous power. On an unregulated power supply, the nominal (rated) voltage is only supplied under full load. When power draw is lower, the voltage rises - the difference can be considerable on a small power transformer. Because the AVERAGE power of music is always lower than for a sine wave, the voltage across the capacitors will rise up much higher accordingly-- this means on music peaks there's lots more power available (because of the V-squared in the equation). I hope that makes sense, as it's hard to answer quickly in a KZbin comment LOL

[@amitghosh6966]

@@johncoops6897 thanks a lot!

[@amitghosh6966]

@@johncoops6897 1. Does an audio amplifier operated on Single supply and Split supply output same power on both configurations ? 2. How much current can a 12 -0-12 v, 2 Ampere transformer provide ? 50℅ or 75 ℅ of the rated Ampere ?

[@bob-ii8oe]

please open those large caps to see whats inside

[@1pcfred]

We know what's inside. Still would be funny to see it though. Cut them WIMAs open too. They're fakes. Like John said the power amp ICs are real. That's probably the only real parts on the board. I suppose imitation is the sincerest form of flattery. They should have made them Black Gate caps. If you're going to go then go all the way.

[@laurynaslauris9677]

those are my favorite chips it is sad that texas instruments does not produce them anymore. So I don't think they were original so as capasitors. P.S. good review.

[@laurynaslauris9677]

@@jim9930 yes, last batch. And to ship them to europe taxes and stuff it is not worth it. time to move on to D class.

[@jj74qformerlyjailbreak3]

I almost bet there is a Chinese Magic Trick going on in that Cap.

[@CraftAero]

Wait, Snickers let you plug in the soldering iron without inspection. I swear mine know that the moment I plug it in, they need to do a close up inspection. Long haired cats and soldering irons, wtf ?

[@laxr5rs]

Cool. Big caps. Keyword: Clampulated.

[@2626sylver2626]

Sorry but for me Snickers is the main attraction in this video the rest is just .001 important 😁😅😊😊🤗🤗🤗

[@iblesbosuok]

Unfortunately this board applies 78xx & 79xx regulators which are noisy.

[@johnyang799]

It doesn't really matter in an adequately designed circuit.

[@JeffrayCrownwell]

I wish I could find an honest review made on amplifiers with an excellent sound quality....NOT reviews made on scraps! I know it's a really good thing to be warned NOT to buy those AWFUL amplifier boards but I REALLY wish to see something different even if I had to spend more than $100.00 on a board so I could build that Boombox and see everyone want to enjoy some nice music.

[@bendermi]

Me too I'm also looking for an amp up to 32 Volts.

[@mwint1982]

Oh my god I love u

[@royservice]

Goot 👍👍

[@johncoops6897]

7:05 puts capacitor on meter and says "about what they should be".... UMMM - NO. (EDIT, actually YES, read below) The cap is rated 10,000uF and the meter reads 9.463uF. That's only off by a factor of one thousand LOL EDIT TO ADD: MY ERROR - There was a video cut at 7:05 and the multimeter range changed fro uF to mF. I didn't notice, so my comment above is not correct.

[@1pcfred]

Come on, 10 is close to 10,000. The first two digits are exactly the same! What's a bunch of zeros add up to anyways?

[@johncoops6897]

@@1pcfred - maybe John went into "Euro mode" and classified that dot as a thousands delimiter?

[@1pcfred]

@@johncoops6897 it happens.

[@slm60uk]

I thought the same, but on rechecking the meter reads 9.463mF, which is if I'm not very much mistaken 9463uF - so close enough. I'm sure if it were only 9,463uF John would have come back and commented on this or his follow up video.

[@johncoops6897]

@@slm60uk - well spotted, and you are correct! I missed the jump-cut at 7:05, so he started on the uF range and I had remembered that. Then after the cut it displayed 9.463 but the range had been changed to mF. Unfortunately I didn't even look at that part of the display. I have edited my comment above to correct my error.

[@listerine-pr5lt]

Why don't you try to address the issues if it is a quick fix and show us how it get improved with simple measures . That would be more of educational and we learn from your skills. After all it is only a 30$ Amp .

[@joshuawang5859]

wima are used, Rubycon are fake

[@hubabuba9051]

You are madnes frend😂😉

[@wolidhassanbadol4045]

SONY DXA-C70 Transformer 27 0 27....yes/ no....LM 3886

[@1959Berre]

Please John, remove the crackling plastic wrap before manipulating the board. Wearing headphones, that sound is the worst.

[@1pcfred]

Next week it is fingernails on chalkboard. All you non-hackers need to be driven off! Elvis Costello used to pump white noise into the auditorium before the show to clear the venue of all non-fans. There is no room for the weak!

[@bendermi]

@@1pcfred Why only non hackers?

[@1pcfred]

@@bendermi because they are not worthy.

[@bendermi]

@@1pcfred You must be kidding hackers are worthy?

[@1pcfred]

@@bendermi people that can take it absolutely are worthy. Perhaps you are using the wrong definition of the word? Hackers != system crackers anyways.

[@isoguy.]

Nice vid but 5 adverts in a 20 minute vid I just lost track of what was going on so lost interest in what was being taught. Can you imagine an advert every 4 minutes while in college. Untenable. I'm unsubscribing from all content makers that have introduced mid roll adverts. I quit tv because of too many adverts and if the greedy tube doesn't change its policy it will be going the same way as the tv. E.g. lose viewers. Greedy, greedy tube.

[@bobrolls3800]

Counterfeit Chinese parts and low quality workmanship turned what could have been good into something of questionable quality. Can we buy good Japanese parts separately?

[@steveswan5714]

Nice cheap amp john 👍

[@stevenbliss989]

Experience with MANY fakes tells me that fake audio chips have much smaller output trannies, which for whatever reason tends to cause oscillation issues into 4 ohm loads.