How an Amplifier Works - What happens inside a car audio amplifier

[@jonreiser2206]

Wow! That helped me to understand, but my head hurts now. My Dad, a retired electrician tries to explain this stuff to me and it goes completely over my head within the first 20 seconds. You have a better way of explaining this. Thank you. It makes me want to read whatever book you read to learn this stuff.

[@richieb74]

so whats that big think in the middle with the fan doing?

[@easyamp123]

The LC filter in front of the core is not there to filter out anything coming in, no appreciable noise transfers through the power supply . The LC filter is there to filter out the high frequency hard switching noise created by the fets that will, if not filtered, put a 40khz and up spikey square wave back out onto your +12, making a huge antenna and will make other electronics in the vehicle fail and work erratically. It is required by the FCC, read part 15 of the FCC rules and regulations. The npn and pnp transistors are not on the top and bottom as you pointed out, they are right next to each other. That boss amp uses the 2sc4467 2sa1694 Sanken audio transistor pair.

[@JamesWattMusic]

interestin. so much history in boards

[@haroldwilliams8242]

what re them six green things called next to the driver transistors?

[@alanmaier]

+Harold Williams The large ones are known as emitter resistors. The actual signal from the output transistors needs to have a very small "buffer" of a fraction of an ohm, as well as an inductor (coil) for stable operation. The same applies to home stereo equipment as well.

[@claysonwebster1622]

what's that blue wire for the wire with the ring terminal

[@dowhatyougottado916]

Hello, what part of the amp would communicate with the ECM on an Audi A6 to allow the amp to power the speakers? Trying to figure out how to bypass taking my car to the dealer so my amp doesn’t have to get reprogrammed.

[@casterofmagic]

I managed to shake the desk where my amplifier is standing really bad, while it was playing. Any chance it might have been damaged?

[@timothyhinton5665]

I have an old amp that played fine until it popped a fuse..I replaced the fuse and it popped again as soon as I turned the key on with no music playing...I haven't tried anything with it since then because I do not want to cause any more damage? Is this something that has an obvious fix or could it be a number of things? It is just sitting on a shelf collecting dust but I love that old amp 1990's Soundstream ref 500

[@frederickirv11]

I have been looking to find someone to explain this understanding for years now. Thank you very much.

[@brandongildharry5848]

Could that pulse modulator cause fets to blow in a row?need some help

[@mikeanderson5985]

same resistor keeps frying, i can hear relay coming on, but then frys resistor, do i need to replace transistors, im new to fixing amps, its a concord hpa-51

[@ATXbigbody45]

Quick question my amp turns on and everything but does not put out any sound. Wiring and fuses are good as im running a smaller amp. Any help on how to fix it

[@Elitemonkeys32]

Quick question, how much voltage does the transformer in the amp output? could you make some sort of inverter out of the power supply side of the amp?

[@TheAmpLab]

The voltage all depends on the amplifier. But no you can't make a DC to AC inverter. Even if it did produce 110v AC, it would not be at 60hz which is what standard US AC runs at.

[@ryanjoyner9236]

Can I ask where you learned your knowledge? I am very interested in how audio components work and would love to find a source for condensed hands-on training.

[@TheAmpLab]

I've learned it over the years. But Perry Babins site BCAE1 is a great place to learn a lot. Just Google it.

[@ryanjoyner9236]

Perfect. Thanks!

[@RGVto512toVA]

What can cause a power drop when volume is increased? Even the LED light flickers. I have enough power coming in. I have another amp that runs fine on same hookup. Problem amp Boss CH2502

[@SirCharles.]

I have an old SPL dk1000 amp that was in my car and it slowly stopped working. first it started cutting out while running a pair of 12s and then finally went dead with no power, fuse intact. I haven't opened it up to look yet but do you know of any common problems that would cause the amp to lose power completely? blown fets? I have a multimeter, just don't know what to look for/what could be fixed, if at all.

[@Exorcism47]

Hi. I have an MTX XThunder X1000D amp, when connected to car battery and giving power to it with the remote wire, I can see the power LED pulsating/fading; it is noticeable only if you look carefully at the LED. Here is the problem, when the amp is on and I have my CB radio on as well the CB radio starts getting jamming sounds as soon as I remove the remote wire from the amp, it’s all good; if I turn on the amp again, it takes a couple of seconds and it’ll start jamming the CB radio. Now, my question is, could it have the high power capacitors damaged? Or something else, ‘cause that LED tells me something is wrong with the amp. Please help me!

[@proteus1]

Is there any diffence between cheap speaker cable and the more expensive cable.

[@ARUNMADHAVAN007]

wow... great job brother. you explained like cutting a piece of cake... Thanks man.. cheers.

[@Grayback1973]

Is it true that replacing the op amps with better ones will improve the SQ in a drastic way?

[@dl3130]

What usually is the cause of a amp to be stuck in protection mode, i have a few that i refuse to throw out?

[@hoodhounds22]

Nice job .. can u explain why a amp is in protection mode? My car amp is in protection mode ..

[@juanrivera4938]

Hey! incredible content! Some feedback: - I would do the resume first so people with more knowledge gets the info right away, and then if they're interested can look the more spec long version. - Try to do some steady shots, its quite simple. use MKBHD, jonathan morrison, etc as an example those are awesome - please do more of this :) I haven't seen anything like this and theres a huge market for it. Make a pantreon i would totally help. Cheers and good luck mate!

[@davidojeda725]

thanks for the video sir. one of the mos explicit videos on amplifiers explanation. Would apreciate your help. I am trying to repair my subwoofer class d amplifier. I got a green light no proctection light, however there is no output signal voltage. RCA have continuity to the board, i am wondering is the OPAMP are bad and not turning on the output mosfets?

[@proteus1]

Is this any different to a stereo hi fi amplifier? What components make an amplifier sound better than a cheaper version? Would it be the output tansistors ?

[@djhinormas959]

hi mate i bought a q4000 amp and the question i have is when it says • Rated Power: 125 Watts RMS @ 4 ohm x 4) does this mean each of the 4 channels has 125 watts rms at 4 ohms or does it mean it has 125 watts rms between the 4 channels at 4 ohms

[@smetanavichlamanov8103]

Each single channel is driven by 125W RMS output ×4 not 125W across all ×4.

[@djhinormas959]

@@smetanavichlamanov8103 6 years later i got my answer cheers mate , ;)

[@trei2unu]

this is really helpful understanding the basics! I do have a curiosity though, can the amp be powered by an external transformer that has the rail voltage need by the amp, pretty much bypassing the amps power supply and feed it lets say at the power capacitors with a + - 20v ? like in the case I want to use a car amp at home, and don't want to use a 12V high amp p supply

[@bassnatics]

yes you can but then the caps must change

[@radiotek4023]

bassnatics caution you may also 'bypass' any *protection such as dc on the output or over current conditions that the switching supply would shut down in

[@javierlozano4066]

The are a nice video but can you can fix my 1500 zx mono black kicker they kinda burn oje side

[@dl3130]

What usually goes bad in a amp?

[@samsungg1630]

So what happens when you have a rail voltage of 91v on one side and half the voltage on the other side ?

[@basshead9793]

I have a phoenix gold tantrum 1200.1 the amp turns on and I get 0 sound but the sub reaches full Xmas and hums any idea's. I've removed the amp from the car and replaced it with another amp and it works fine. I've tried bench testing the phoenix gold with the result no sound just hum's and the sub goes to full xmax

[@vintagestereobuff7005]

Sounds like you have Direct Current at the amp output which is pushing the cone out and holding it there. It could eventually cook the coil of the sub. But I'm not sure which component is faulty allowing this to happen.

[@joshcassler7252]

I have a memphis pr 1.500 I'm trying to test it with a computer power supply my question is I have power on the amp but can not get signal to come out of the amp I'm using my house equalizer to send signal to the amp do you think the amp is blown or is a power supply not enough to run it? Ps rca's are good

[@TheAmpLab]

A computer power supply is not ideal to power an amplifier. It could very well be bad, but I would still change the power supply. does the amp power on?

[@joshcassler7252]

it's powered on and the cooling fan runs but no sound coming out of it I know the way I have signal going to it won't have volume control but I turned the gain up and down sub sonic filter all that no sound I threw power to the sub with my house amp just to check it's not the speaker

[@TheAmpLab]

+Josh Cassler Could be a ton of things. no way of knowing without seeing it in person and really testing things.

[@joshcassler7252]

if one end of the rca plugs is in the amp and you touch the other end of the rca you should get a hum or a buzz or somthing it's dead not even a crackle it takes pretty big Guage wire to run if it's not getting enough power would it still be able to turn on just not put out sound

[@TheAmpLab]

+Josh Cassler I have seen that, yes.

[@delandgoon]

my gain knob on my amp broke now that channel has no sound . could that be fixed?

[@leopaulevans7573]

hey if one channel out my 2 channel amp not working wat are the stuff i can check to see if fail

[@zavaroudikos1]

Hello, I have an amplifier and it doesnt work. Its lights are ok. Everytime I turn it on with the subwoofer connected 2 small components situated next to each other named C4467 and A1694 get hot. The speakers work fine because I connected them with my house Amp. If I change channel to my subwoofer then another set of these components gets hot equally. Moreover if I coonect only the speakers without the sub then it gets hot but slower. PLEASE help me...!

[@aaronjohnson8715]

A quick google says these are your NPN and PNP transistors (they handle the power going through the speaker). They should be attached to a heatsink, but if they are in a 'low power' amplifier, that might not have been necessary in theory. Speakers have different resistances (16, 8, 4 ohm are common) which means that if you use the wrong one, you'll get more volume through it, but much more current will run through the system, heating up components. A simple way to solve this would be to heat sink these, if you must use those speakers. If you'd like to do this, the simplest way would be a drop of super glue and a small piece of metal (preferably with fins) attached to each chip, to help spread the heat (use electrical tape to prevent the metal from touching anything else, and don't let them touch each other. Many transistors/mosfets conduct current through the heat sink). * I take no responsibility for any damage to your equipment, you should look into heat sinking before following this advice.

[@radiotek4023]

Disconnect the speaker and check what the voltage is on the speaker terminal. It should be very low around 20/30 mV or less (0.020/0.30 volts) if it is volt/s you have a offset problem.

[@psycho2soundz]

what causes a amp to play fine up untill it builds heat? i know heat isnt good. but it happens. i use a peizo buzzer to set my gain so im sure im not clipping. ?

[@TheAmpLab]

Sounds like the load impedence is too low for the amplifier. ie a 1-ohm load on a 2-ohm stable amp.

[@psycho2soundz]

+The Amp Lab you would think..but. it did the same thing to me at 2ohm as its doing on .5.. i can play it for 30 min maybe full tilt and it will then go into protect untill i let it cool. i opened the amp and i see no burns or anything funky... i have 4 batteries. and i am constantly monitoring voltage. i just dont get it. amp is a lanzar opti 7k

[@psycho2soundz]

+The Amp Lab also the amp is .5 stable

[@vintagestereobuff7005]

It could be thermal runaway in an output transistor. When the transistor gets overheated, it's junction resistance drops, causing more current to flow, causing even more heat and lower junction resistance, causing even more current to flow and, you get the picture. I diagnosed this problem about 20 years ago on my vintage 1979 fosgate pr250 amp by spraying the transistors with "component cooler". Let the amp run until you start to hear the "noise" then start spraying the suspect outputs. If the cooling action makes the noise disappear, you have found the culprit or one of the culprits. Also, chances are, that if an output is defective there may also be driver transistors and resistors ahead of it that could have been the cause of the output to become defective in the first place. I AM NOT a formally trained technician, just some guy who has tried to fix a few things on his own, sometimes with success, sometimes with failure.

[@psycho2soundz]

vintage stereo buff wow thanks for the response. I will look into it. I need to figure out what Is what

[@anarchist393]

question: I have an alpine pdx m6 and it gave up on me taking my woofer with it the amp powers up; but it is sending DC power to my speaker any idea what may be causing that so i can get an idea if it is worth fixing?

[@smetanavichlamanov8103]

Amps work with dc not ac

[@OldSkoolF]

The BEST explanation and example on KZbin.... Thank you!

[@Headshothorror4488]

I had 3 risistors burn up right by the transistors or 3 prong black square things. Why ? If I replace them will they just burn again.Also it worked and I heard music from a very small speaker,iput on my subs then it fried. Worked before subs butsubs are fine just couldn't handle it I guess. Also how do I replace the resistors and get same ones ? Ones that fried are just like others next to them so how can I test them to see whati need

[@alanmaier]

+Headshothorror4488 Those emitter resistors blow for a reason, and you need to fix the reason. Those rarely blow, so you've got major damage somewhere.

[@Headshothorror4488]

+Alan Maier They are 10 ohm I think , it fried up only one in a set of four but is 10+ yra old. Also worked on a small speaker. New amp , it will get loud and normal then just goes half as loud outa nowhere ? When I press on the amp cover it gets loud again , when I jiggle the RCA connectors same thing. Could a loose RCA cause this as in the amp loose not wired RCA those are new n Memphis. Is the a ground wire in amp ?maybe loose, its a mtx tc300 CEA 2006 rated but old.

[@jodhpurmehsana]

Hi mate are you able to help me out with my home subwoofer amp?

[@johnnymnemonic8487]

I've been looking for a video that explains the basics of a car amplifier. Thanks for the video

[@bigredtruck42]

THANK YOU!!!!!! This was probably more informative than any other video I've watched. I'm trying to repair a RF power 1000 and know how to test individual stuff but never quite knew how the flow went.

[@AlanMedina314]

You made op-amp feed back easier to understand by a brief mention. Cool...

[@robertdenaro3514]

Hi I have a question , can someone change the output capacitors inside a amp put bigger ones to get more dynamic power ? Can a amplifier be modded ?

[@smetanavichlamanov8103]

That's what I want to know. Ive been searching the entire internet and can't find a thing on exactly this question 😔

[@chillpill4936]

Hi mate, really enjoyed the video! Just what I wanted to know! Now....I have a 1000 watt boss amp and I'm certain is does not put out 1000. Can I make it a better amp by replacing the caps and MOSFETs with better quality items? Thanks

[@alanmaier]

+howitis howitis No, you can't just install better or higher rated parts. That will improve reliability, but the actual output power is truly designed into the amplifier. When a company builds higher and lower wattage versions of nearly the same amplifier - there are other parts also changed to match the designed output.

[@Dillon1791]

I'm trying to bypass the built in internal amp on a 90s Honda radio, basically converting it from high level out to low level out for a cleaner signal to an external amplifier. Also looking at upgrading the DSP and other preamp chips where possible if anyone has any tips. I have no idea where to find circuit board and chip information if anyone can help.

[@DominicVBASSISLIFE]

why does my amp make the subs pulse and when the subs are not connected the protection light turns on

[@Headshothorror4488]

How do I know what resistor I need ? Some fried so how do I know which to get ? I have a meter but am a Engine guy

[@sanmantech5238]

Can u please tell me how to get only bass from my amplifier

[@sanchezdaniel2007]

My amp goes straight to protect mode what can it be its a 4000.1w spl

[@fatmanquanproductions853]

Where is ur shop

[@sorwis]

thank you. extremely simplified and very informative for someone just learning about audio amplifiers.

[@winebottom6664]

What Amplifire Is That?

[@ericbrandt5690]

ayy bro I have a hifonics zues zx6000 I green power light on powers up fine but no sound what could it be???\

[@TheAmpLab]

A LOT of things. Most likely an open output transistor though. Could be a bad power supply as well. Some amps "poer" lights simply run off the remote turn on and give no real indication whether the amp is working or not.

[@Lord_Dillinger]

I had that same AMP, found out that 1 channel was blown in the amp. GL

[@radiotek4023]

Loss of a pre amp power rail? shorted cap etc..

[@sneakyquiet414]

Wish you could do that for tv mainboard and power supply

[@prestonsmith649]

Yo big dawg u explained this better this anyone else

[@AmplifiedCarAudio]

Hey man awesome video I learned a lot. I have a question though, what would cause an amplifier that's powered on to almost catch on fire without having any RCA's plugged into it?

[@kenteikenjr4551]

What does it do with rcas plugged in? Sounds like you have a dead short somewhere in the pwr supply region.

[@bryanvarin347]

I would like to say that you explained it to the T I had a hard time figuring out what was what but you had the best one thank you

[@jacobleedowney]

@8:19 but I wanted to grind the rails with my skateboard! Also, I've been scouring amplifier vids, and yours is the best. Well done!

[@kskate91]

I worked on a power bd1000.1 a while I almost forgot the four big 100v caps were still charged! Had discharge them

[@ilovetoyotatrucks]

I gotta old massive audio 25.4 I believe it is a 1000.4 it's hudge more than half the size of the competition 1500.2 I had from them awhile ago, it still works great but the rca's input are loose I was gonna just open it up & ca glue it but what might you recommend I have lots of experience soldering but iv only dabbled in motherboards when somthing easy broke or I would bridge the old aux cable mini portable speakers to make them LOUDER but I don't have/own a vacum or anything just basic solder stuff,even 6% silver solder but im all ears

[@motorman92]

Mate, Thats a Terrific Explanation, on how an amplifier works. learnt so much. thank you. really interesting

[@Bassotronics]

Awesome info. Thanks!

[@Llegando_Tarde]

This helps alot thanks for taking time to make this. I am studying components of an amp and this helps tie most of it together

[@AlexTran]

Thank you I kinda a noob when it come to amp and I still don't understand much after but this video help me a lot!

[@Kennynva]

How about an amp that has distortion at any gain..and the head unit is ok...

[@quasidynamic]

Wow. Excellent walk-thru and well articulated! thank you so much for demystifying these magical devices.

[@MechaTronic161]

Impressive explanation but you've pointed on wrong direction @ 9:15.

[@1frankmolina]

I never understood capacitors as dc filter

[@ZenithClarity]

Very nice breakdown. Thank You.

[@THELIFEOFPRICE]

nice video

[@domeezy]

Whoa!! Great job. Never knew an Amp was this complicated

[@speedtoast]

Hi, if this has a PWM. That makes it a class D right? Cheers for the vid buddy!

[@dawnminilla9299]

The pwm "pulse width modulation" is the for the power supply, this is a class ab.

[@dannyboy768]

Something weird happened to me. I bought a used amp. So I connected the ground wire, the power wire and the remote wire. Amp powers on. Then I removed the power wire. Amp still on. And it stayed on for a few minutes until I removed the remote wire. Everything I know is a lie?

[@gotjunkin1401]

YES IT IS 😆😆

[@joshcassler7252]

If it is turning could it be fixed if it won't cost an arm and leg I'll pay you to fix it if it's not outrageous price

[@AthmanJoSam]

Good tutorial bro❤️👍🏻👍🏻

[@thrtyhz]

Great video, haven't seen anything else like it.

[@sc0tte1-416]

Thanks man...you really did a good job of explaining how these amps work, thanks and cheers to you brotha! :)

[@sc0tte1-416]

Also, it looks like the tracers from the transformers or wherever the main voltage is handled looks like it's not the biggest gauge. Would shunt mods work on these or would it just be detrimental? Thanks

[@sawajiri100]

Transformer act like inverter. from battery 12V D.C goes to transformer and mosfet switched in to ground to make secondary voltages A.C example 48V AC. switching speed by control i.c pulse modulation

[@TheSjb1000]

very informative video very easy to understand thank you u answer all of my questions

[@blu101-o3t]

How much well you change to repair my amp ??!?!?!???!?!????!!!!

[@electronicshelpcare]

Well explained...

[@kavindugilshan]

simple and best explanation thanks you very much !!

[@hiphopaddict007]

Great explanation.

[@vaibhavkundalwal5283]

Hey man nice video, i want to start a speaker company. gathering knowledge if you get time let me know want to discuss more over call. Thanks

[@Tewthpaste]

so i have a infiniti G35 coupe with BOSE amp and when i turn the radio on there is no sound at all and everything on that head unit is working and if i press a button to set a radio station i do hear that beep noise on all 4 speaker that let me know that the station has been set. its just no sound from the radio through the speaker and when it does it will usually make a popping and crackling sound and if im lucky then the sound from the speak will work and sometimes it will be stuck on a particular volume level and if i up the volume or down the volume it wont change the actual volume at all and if i do sometimes the sound from the speaker will stop working then i will have to turn the power on and off on and off and crank up the volume with that popping/crackling noise until i can get the sound back on. im sure it is not the speaker because all 4 speaker do work perfectly when there is sound and i open the head unit and check all the wiring and grounding and cant figure out what is the cause. i check the amp by just looking at it and checking the connection and all seems fine. so im not sure does the Amp also control the sound/ volume from the head unit to the speaker?

[@sloppyengineering]

great explanation. thank you

[@Techscrews]

Nice video, thank you!

[@souprchrgd]

Good information . Wish That I could send you all of my blown amps

[@paulknowles653]

Hi, just saw this today. i may have blown two amps :( Basically the first one i connected the ground, but the live to the Live speaker out from the amp. It's smoked a hell of a lot. What could be burned out? 2nd amp I momentarily connected ground and live wrong way around. The connection sparked. However i don't know if this amp was working anyway. Both units a re 2nd hand. Great if you have any input.

[@paulknowles653]

***** I have of course checked the fuses attached to the amps.

[@paulknowles653]

Thanks for the speedy reply 😀 that was back in june/. Amps were OK/ car sold. Cheers

[@SylvainBOSSON-og8fi]

Exactly what i need thanks very much

[@professorjack2099]

It's really annoying how all amplifiers put the positive battery input RIGHT NEXT to the ground to chassy. Just asking for a short to ground.

[@hearthacker2658]

Send pdf file

[@exo571]

very good video.Thank's

[@SANDSHOE]

I have seen in electronics many parts and appliances work indirectly on DC current .AC current works because of their long path journey available otherwise DC wins in every case...

[@jeezee007]

Great information bro!

[@jaroxmuzik8601]

Dude. Thank you! Your awesome!

[@corylemaster8922]

Great video ! Keep it up.

[@hectorortega9131]

Awsome vid. tnks

[@H3YdUD3]

technology is amazing