Yamaha DBR10 Repair and Review - Spoiler - It's a Great Speaker - But it still failed !

[@ryanybos]

Excellent DBR10 circuit insight John B. Thank You for the upload & useful information.

[@JohnB-2021]

Thank you kind sir, have a great Christmas.

[@Conservator.]

“If you don’t have any component wire, just use the wire of some component” Brilliant! I enjoyed this video. Every 33’48” of it!

[@JohnB-2021]

Thank you kind sir

[@ethanclement9647]

Thank you for your phenomenal video. In this through everything out world we live in this is a breath of fresh air that things can actually be repaired and repaired as good as new or better!

[@JohnB-2021]

Thank you for your kind comments Ethan Clement

[@chrisbircham221]

Hi John. Great videos keep them coming. Re the 6.8 ohm resistor, If you look at the circuit, the relay contacts are across the 6.8 ohm. when the power is turned on the relay is open and the 6.8 is in series with the rectifier. the power supply then starts up and produces the -15v line which turns on the relay , shorting the resistor. A nifty way of producing surge protection. .This is very common in these types of high power amplifiers (the Mackie SWA1801 uses a 22 ohm 20W resistor in this way.) also if you look on the pcb adjacent the fuse holder, the correct fuse rating is printed there for reference.

[@JohnB-2021]

Thank you for your comments but most manufactures use in rush limiters and the 1801 is at least a 15 year old design, I've repaired many.

[@Rojgonz]

Hi John, I love your videos and the way you explain things easily! I’m in the states and a used Yamaha DBR10 brought from Australia is up for sale that I’m considering buying. However, on the back it says 220-240V. Will it still work properly/perform normally on 110V or will some modification be needed? TIA

[@JohnB-2021]

Yes it will work on 110 volts. Thank you for your comments.

[@thehitman5007]

Fixed a DXR12 series recently, no power. Same resistor blown, checked the fets, it was alright. Replaced the resistor, unit turn back on, sound was ok. If you power cycle, the resistor will blow again. Guess what? The culprit was the main capacitor. Replaced it, walla no more blowing resistor. Best part, the capacitor showed normal reading with a capacitor meter. Update: Spoke too soon. It blowed again after using for couple of hours. Now im lost.

[@JohnB-2021]

You need to put a scope on the psu to make sure it is switching correctly.

[@philipdonovan6510]

Thanks for putting this up, will be getting a pair of these soon and being an electronic tech by day and hobby, this is very helpful and insightful to the function of the PS. Nice.

[@JohnB-2021]

Thank you, I'm pleased you found this helpful.

[@diedraak1]

The original 6,8 resistor look alike is actually a resistor with a built in thermistor. It is not a normal ceramic resistor. Made for Yamaha. I usually replace with a 10 ohm thermistor as you did.

[@JohnB-2021]

Thank you for the info, I forgot to have a closer look. Maybe a thermal fuse at 142 Degrees C?

[@JohnB-2021]

Hi, what will pop, the SMPS or the fuse or ?

[@diedraak1]

The 6,8 ohm will pop, usually unnoticed.

[@JohnB-2021]

Thanks for the comment, but if that resistor pops, I'm sure most people will notice because the amp wont start up.

[@homeradio9810]

I was deciding about the purchase between the Mackie and Yamaha and your video made up my mind.

[@JohnB-2021]

Thank you for your comment I think the Yamaha will be more reliable.

[@akdultos]

hello thanks for your videos... how to fix a tweeter??

[@timb2597]

Hello, thanks for your video. My low frequencies have stopped to work from one day to another. And the high frequencies seemed to be kind of filtered. Do you have any idea of what could be the problem ?

[@JohnB-2021]

Sorry no idea, I only got to work on the power supply. Try calling Yamaha, they do have tech support.

[@michae338]

Hi John STF28NM50N has explode in my DBR12 , is it affected by other parts? and why it can explode? i will be waiting for you answer, thank you

[@JohnB-2021]

Hi Michael, Yes it will have blown the resistor (probably) The FET type is probably not the best choice, it's difficult to know if they get too hot or the voltage is going out of the maximum spec somewhere.

[@marulituahutabarat6285]

You can replace the mosfet 28nm50n because their absence in the market by K3683 and modified some resistors.

[@Retrobution]

my dxr 15 died tonight and just trying to do some research on how to repair. when i power it on the protection light and the light below comes on for a split second and that is all that happens 😔 no flashing etc

[@marulituahutabarat6285]

Maybe the pwm ic L6599D defective.

[@yaminhameed1524]

Hi John B, nice video. I just wanted to ask why not having the PFC circuit on the switch mode power supply would be a good thing with active speakers. Thanks

[@JohnB-2021]

Hi, Mackie had a PFC circuit on their 450v2, it boosts the mains from 320 volts dc to 380 volts dc. 8 in 10 failures of that amp will be the pfc circuit. There's nothing wrong with the pfc design, they just don't last with the high voltages and currents involved.

[@davedrozario9096]

A big thank you, John. Lovely video and truly informative.

[@JohnB-2021]

Thank you too, I'm pleased you liked it.

[@djrickstartv]

Hi thanks for the videos, is yamaha comparable to qsc ? they both offer 7 years warranty but qsc is a little more expensive. i have a pair of qsc k10, but wanted to give yamaha speakers a chance for my next set of speakers.

[@JohnB-2021]

I believe they are both good quality speakers.

[@Jobayori]

Hi man, my DBR10 volume knob is broken, do you know where or how I could replace it? Would appreciate any tips and advice, thanks man

[@JohnB-2021]

Maybe Yamaha can supply spare parts.

[@ralphison]

whats the part number of the class D amplifier board?

[@Noah-gq7pq]

if ya use a variac,,and monitor the current will that keep ya from damage,in case there is a surprise you don't know about?

[@JohnB-2021]

No it won't help. You need to limit the current .

[@Noah-gq7pq]

@@JohnB-2021 got ya ,,you forgot more than i'll ever know,,all i have is a piece of paper with lincoln tech printed on it,,but you do this stuff,you know what your doing,,i guess the variac just brings up the voltage,,but if there's a short it will pull tons of current no matter what the voltage is,, i think

[@JohnB-2021]

@@Noah-gq7pq I think you should power up the power supply control chip with a bench power supply and make sure it is switching correctly. It is what I do on Mackie amps. You do need a scope and external power supply. Or, change the chip and transistors and put a 2 amp quick blow fuse in.

[@bilelbolbolii3502]

hi John i have the same problem how everything i do like you at the video my nothing the power does not turn on help me thank you

[@JohnB-2021]

Have you replaced the resistor and checked the fuse?

[@mikeycbd]

Having a day of electronics today. Even I wouldn't have done that to the resistor, maybe not even using a solder sucker either and overheating both legs and pulling it out. Anyway thanks for another great video JB aka twin.

[@JohnB-2021]

Yes I see the problem often.

[@abeltrujillo8413]

Thanks for your video. I have a pair DBR-12 and only the rca input works . Any idea what could be wrong?

[@JohnB-2021]

If the XLR inputs worked previously, they have been over driven and maybe blown a small resistor or something.

[@abeltrujillo8413]

@@JohnB-2021 thank you! I’ll check the circuit to see if I find it.

[@abeltrujillo8413]

Do you have the circuit schematics by any chance ?

[@JohnB-2021]

@@abeltrujillo8413 there are links in some of the comments below

[@dannyharvey8245]

Hi John, some good insights into Yahaha engineering, thanks! Thinking of replacing my 20yr old wharfedale EVp 12p Speakers (one unit has developed a clipping fault) with Yamaha DBR15s and usefull to know quality of internals, availability of parts, etc.

[@JohnB-2021]

Thank you for your comments, Yamaha DBR15 from EVP 12 lol. Ford Focus to RS

[@jacklazyj]

I have some active speakers Alto TS 315's 2000 watts each only two years old one of the speakers does not power up some days and some days it does.the fuse is good opened it up to check connections after a visual inspection I see nothing wrong,I left it on for a while to see if it would heat up and shut itself down.I have done this twice and brought it to a gig and it would not power on with three different power cables when I get it home it powers on.....please help

[@JohnB-2021]

I have never seen an Alto; and if I had you're asking the impossible. i.e. diagnosis without checking everything with a scope.

[@georgeralston]

Hi John B, good work in both presentation and process. Im a bit mad since when moving from US (120V) to Europe (230V), i thouhg i read tehre was an internal voltage switch. No, not true. Now im thinking best way to resolve. Could buy a new AMP board, but freom where? Or perhaps, cut the two legs off the bridge to change it from full wave to half wave, and perhaps need to change from front end compontents too. Suggestions to mod the front end of the power supply? BTW, i could not find the schematic, to check trafo details. Its all wrapped. Can you share? Great job, many thanks, George

[@JohnB-2021]

Thank you for your comments George. The power supply is rated for 120 and 240, no mods required.

[@georgeralston]

@@JohnB-2021 Thanks for your quick reply John, I dont have the schematic, I thought I read it could be changed, but i seen no switch, and have not come across different board models for the various markets, they all seem to be type YF909. Its safe to go ahead with 230V source? On another note for my CR5 mackies, im looking for a 230V/15/0/-15V 1.5A trafo. You can recommend a source? Thx!!

[@JohnB-2021]

@@georgeralston Farnell, RS Components, Mouser, DigiKey

[@georgeralston]

Hi John, I pulled out my speakers, and decided to go ahead and plug it into 230V. Seems like the power supply is not rated for 240V. Some key changes between the euro version and US version. ell - Bang and lots of smoke. So now im sure its damaged, probably the 1000uF caps. Do you have the schematic you can share? thanks.30/9: Found the schematic, looks like i need to add the jumper to limit the voltage and swap out a few resistors.

[@arvinrebong2990]

Hi can you share the link of schematic diagram of yamaha dbr 10.

[@JohnB-2021]

It’s on google

[@arvinrebong2990]

@@JohnB-2021 its free or paid? I found 1 but its $12

[@JohnB-2021]

@@arvinrebong2990 Hi, It's free. elektrotanya.com/yamaha_dbr10_dbr12_dbr15_sm.pdf/download.html

[@MicrosiMe]

Nice Video, you should have NOT replaced the resistor with that NTC. the reason is that the 6.8OHMS resistor acts like another fuse. and it has another protection purpose on the circuit. That resistor protected the other parts from blowing up. because it blew up due over current. Putting the NTC in place of the resistor will make it impossible to stop the current draw at next failure. and it will keep passing the voltage and current until your fuse blows up. Also as you can see that your FUSE is bending at power up. reason is that the NTC Resistance will decrease with heat. resistor is resistor and it will not change with heat. YAMAHA knows what they are doing. ultimate piece of engineering. good luck

[@JohnB-2021]

Putting a resistor in line is old school. The resistor does not protect anything from blowing up. If something is going to fail, the resistor is not going to stop it. I didn't want another possible resistor failure, that's what fuses are for ! The resistor means the average consumer will have to take it to an engineer or buy another speaker. You should read up on Inrush limiters, they replace old school resistors. At full power, the resistor would be dissipating power needlessly !! One needs to limit the current at switch on and then at no other time. The fuse is bending because of the current surge which is due to the discharged capacitors, not because of the inrush limiter. You're also telling me how the resistor works, I mentioned in the video, the resistance will not change.

[@MicrosiMe]

John B Ok, resistoe doesn't protect? Make your test again and put a resistor make a short circuit at the 340v line. And see if it will blow or not. I think you didn't understand the idea behind it. Only professional companies are using resistor. Using NTC is not the ultimate solution. Put NTC and see what will he happen next time, your PCB will have more damages

[@JohnB-2021]

I understand what you are saying, but if the pcb is designed properly, the fuse will simply pop. Panasonic have thermal fuses under some of their inverter transformers in tv's, they don't want the system to blow up. In many applications, a thermal fuse is maybe a better option. In my opinion, the 6.8 ohm resistor with internal thermal fuse serves no better purpose than a 10 ohm inrush limiter. Let's face it, the system had blown up, so even Yamaha are not world leaders in SMPS design.

[@yaghiyahbrenner8902]

@@JohnB-2021 The Guy makes SMPS's and is active on diysmps.com obviously he know what hes talking about.

[@JohnB-2021]

@@yaghiyahbrenner8902 Maybe he can tell Yamaha why their smps's are blowing the FETs then.

[@vjncreativevisuals2493]

hi I have DBR 10 ,changing both sets and 6.8 resister also, but same issue all bale components are ok am changing L6599 also

[@TROIDX]

So is it a general issue of DBR's? Should i get one DBR 10 or it can sudenlly be defective in a couple of months?

[@JohnB-2021]

Yamaha give a good warranty, pretty sure they don't all fail.

[@TROIDX]

@@JohnB-2021 Thanks!!!

[@sunandir0168]

sir please? I also have a DBR15 Yamaha LED that won't turn on, where should I check it thanks.

[@JohnB-2021]

The smps like the video

[@Daksi001]

Hello. What's your thought on the internal electronics quality of the EV 112p live x speakers?

[@JohnB-2021]

Ok for a few years but nothing like the power or quality of Yamaha or Mackie

[@rogeragullo4344]

Bonjour , comment et ou !!! pourrai-je me procurer le bloc complet électronique de l'enceinte Yamaha DBR 10 merci

[@JohnB-2021]

Yamaha

[@jeremyschuhmann9671]

BTW, it occurred to me that maybe the way the board got damaged in the first place is that when the 3A fuse blew someone replaced it with a 6A fuse that was meant for the North American 115V version of the circuit. Kind of makes you understand why manufacturers aren’t designing products with external fuse holders these days…

[@JohnB-2021]

Thank you for your comments. Some manufactures will send complete boards to end users / general public, others don’t. I’m not sure about Yamaha. If you take a look at an EV speaker, their amp and power supply board was over £200. I repaired the EV for £65. I’m guessing the Yamaha boards would be double the repair price or more. I think you’re right about the fuse, the amps are dual voltage but marked as 110 or 240.

[@jeremyschuhmann9671]

Very interesting video. You obviously have a lot of experience with and understanding of class D amplifier circuits. I’m assuming that you are repairing a unit that is out of warranty and/or was discarded or sold for parts. I can’t imagine that a Yamaha warranty repair person would get down to fixing on the the component level…they’d just replace the whole PS board. Are replacement boards available to the general public, or do you have to be an authorized Yamaha repair person to order them? If so, wouldn’t it be cheaper to fix it that way (assuming that you do this for a living and charge an hourly rate)?

[@anayuniarti]

Mr. John B greetings can help to get the schematic for Yamaha DBR 10

[@JohnB-2021]

Have you not tried Google? elektrotanya.com/yamaha_dbr10_dbr12_dbr15_sm.pdf/download.html#dl

[@mikedubz5576]

Is this Amplifier reliable and or any good? Looking to buy a pair of dbr12 used.

[@JohnB-2021]

The clue is in the title.

[@jacousticproaudio]

@John B ... How many series/type of diode D 109

[@JohnB-2021]

What is D109?

[@jacousticproaudio]

@Jhon B . diode D109 short circuit do you know what type of diode. because I don't have the schematic diagram

[@JohnB-2021]

@@jacousticproaudio If you don't have experience to pick your own device, spend 10 seconds looking on Google for the manual. It has the part numbers.

[@caiosousa9754]

Hi John. I have a DBR12 and I turned mine on to 220, but it was switched to 110. Any tips on what it could be?

[@JohnB-2021]

The smps works with 110 or 220, maybe it just failed like the one I repair.

[@bangmadit315]

Hai John, I have a Yamaha DBR15, the total cause of generator is over voltage. I check the fuse is still normal. I ask your help to solve this problem. Thank you

[@JohnB-2021]

Speakers with switch mode power supplies should not be run on generators. Your problem is probably the same as the amp in the video

[@bangmadit315]

John B What are the broken spare parts names like in the video? And there's still hope yamaha dbr I live again or not?

[@djrekklessdmv8757]

Hi John. I saw one of your videos where you changed the amp on a powered speaker and I was wondering how I could get more bass out of my Mackie SRM 1850 sub.

[@JohnB-2021]

Hi, I have not changed any amps, I just repair them. Other than using a mixer, you can't get more than you have without changing the speaker. Try the HD series.

[@djrekklessdmv8757]

@@JohnB-2021 thanks

[@shayanghosh6581]

Hello John, First let me thank you for such informative videos. I have DBR-10, the voltage across the drain of the first MOSFET is okay and the in rush 6.8 Ohm resistor is also okay but my relay isn't clicking. Could you possibly please guide me how can i get this thing running?

[@JohnB-2021]

If both fets are ok, the driver must be faulty.

[@bijunarayananviolinmavelik4427]

I have yamaha dbr 15 ..it goes off as soon as the switch is turned on The light stays on for only a second .would you please tell me what the problem is ?

[@JohnB-2021]

You need someone to test it.

[@soundseal]

Hey John, can you tweek with the dps settings? I want to replace the original speakers with better ones so that I have a lower power compression.Can you tell me what impedance are the woofer and the compression driver?

[@JohnB-2021]

Hi, Only Yamaha can tweek the DSP settings, but they are optimised for the speaker. I believe the woofer is 8 ohm, the tweeter will probably be 6 or 8, doesn't matter too much. It just matters if you're going to reduce the impedance of the woofer below 8 ohms, it will start loading the amp and cause it to get hot, that's if it doesn't cause the power supply to go into current limit.

[@soundseal]

Well, I guess I'll stick to the original drivers in that case, without changing the x-over ,phase and eq settings I will just ruin the sound with other drivers.Thank you for the reply!

[@amalgamate860]

I was wondering could those chokes cause noise that sounds like some interference (like from a bad signal from a wireless mic). I have a yamaha dxr12 that is causing some noise and small hum after the speaker has been on for a good 20 minutes. Anyways I'd rather find the specific cause then the complete amplifier replacement which costs a few hundred less USD. Do you think that could be it

[@JohnB-2021]

Hi, No the chokes would not cause any noise. Does the speaker hum with all inputs disconnected? Is the noise from the tweeter or woofer?

[@Altsouza64]

Hi John. I have a Dbr 10, and unfortunaly my Son conected it in a 220v outlet (the speakers were with 110v seting). The amp broke. Any clue where do I start to fix it??? Thanks

[@JohnB-2021]

The power supply is going to be blown. You'll be lucky if it hasn't done a tonne of damage.

[@Altsouza64]

@@JohnB-2021 Hi, thanks. Any clue where to start in Psu? Thanks

[@JohnB-2021]

@@Altsouza64 did you not watch the video? It has all the clues

[@yopoanguiano3322]

hello good afternoon could you help me in something about the expansion board of. Yamaha DBR since an integrator thundered and I am missing some numbers

[@JohnB-2021]

I'm not sure I can help you, are the numbers not in the schematic?

[@rayflexentertainment1545]

hello, I got this speaker off Amazon. with 110v-120v on it, I don't know if it will work with 220v

[@rayflexentertainment1545]

how do i cherck inside ?

[@RaaaaaaandyRC]

So i have the bluetooth one, i can get it to power on and hook my phone to it. One day at work all the bass just went out and all you get is highs from the tweeter. What would be causing this? After that day at work i left it sit for 3 months. I just plugged it in last night and it was actually working and sounded great. Today i plugged it in turned it on and turned it up and all the base shut back off and now all i get is high pitch music coming out. Do you know by chance what would be causing this?

[@JohnB-2021]

Sounds like a dry joint around the bass chip.

[@CostaBle]

John B John, what do you mean by “bass chip”? I’m having a similar problem with my active RCF 2-way. The LF woofer cuts out when driven at mid-high volume, quite possibly at peaks of LF content. All is left is the HF. I’d lower the gain and the LF would come back. The speaker itself is fine, had it tested. could it be the processor/crossover failing, thermal cutoff, or transistor/cap failing? Have you encountered this problem? Any help would be appreciated, thanks!

[@JohnB-2021]

@@CostaBle If you watched the video, you would see the bass chip and treble chip drivers. Youn need to make sure your woofer is not burning out, do you have more than one?

[@RaaaaaaandyRC]

@@JohnB-2021 i only have 1. I called bosh and they told me to ship it to them and they would fix it for free. I decided to go that route before opening it up and seeing if I could fix it.

[@JohnB-2021]

Nicholas Hoover-Hill free is great 👍

[@mohdhanafiahkassim7336]

Hi john. I have dxr 15, how to fix my amp failure.. Only tweeter sound, woofer sound slow...

[@JohnB-2021]

If you're in the UK you could try Real Electronics or a guy advertises Mackie repairs on ebay.

[@studioromamusic4757]

great!! can you tell which compression driver you use in it and / or a replacement? I'm from Brazil. thankful.

[@JohnB-2021]

Sorry, no idea, only know what is in the video.

[@manishabaris6456]

Sir plz help i have Yamaha DBR15 2speaker but today program our after High Wallteg electroccity com so my Yamaha DBR15 speaker's not working and not show to light also

[@JohnB-2021]

It will probably have failed in the same way as the repair

[@manishabaris6456]

@@JohnB-2021 ok thanks sir

[@Jacobskate]

I have a Yamaha DBR12 that I don’t use much, but would use it more as a portable speaker. I want to bypass the mains supply, and directly supply 12-16v to run from a lithium battery. Or a car battery.

[@JohnB-2021]

The Yamaha requires too much power to run from a portable power source. There are speakers out there that run on 12 volt batteries.

[@Shaker4x4]

Yamaha amplifiers are very reliable. I'm keen on a pair of DXR15MkII for a small band studio (need the lower frequencies without a sub). They have a 3-way but the price goes very high. I'd also like to have a Yamaha home theatre amp as well. Owned a big class AB Onkyo and what a PoS.

[@JohnB-2021]

Reliable until they stop working.

[@Shaker4x4]

@@JohnB-2021 Then reliable again after being repaired lol.

[@JohnB-2021]

@@Shaker4x4 except for the fact that them blowing up makes them no more reliable than any other amp.

[@JohnB-2021]

Never seen an Onkyo, they have a good name in the hifi circles and would like to try one.

[@Shaker4x4]

@@JohnB-2021 Yeah no Onkyos in PA gear, I own a large Onkyo HT amp and nothing but problems. Going with Yamaha HT next time. But definately keen on the DXR 15" MKii for a music studio. I need bass, but not subs. I need small stage setup, without the excessive gear.

[@UrsNicu]

Hi John, I have an Yamaha DXR12 active speaker in Protection mode, when I turn on the speaker it makes an nasty sound for about 2 sec and it remains in protection mode, what can I look for inside to try and repair it? Thank you.

[@JohnB-2021]

At a guess, maybe one of the output fets is short circuit which would put dc straight to the speaker. Check the amp section.

[@UrsNicu]

@@JohnB-2021 thanks, will do...

[@a.k1311]

Nicu Urs did you solve it? Got the same problem. Only after 10/20 min

[@a.k1311]

John B maybe i can send it to you and you can make a video off it...while repairing 😁

[@rookystevan5493]

Heloo Jhon.. my dbr is 15". The last i use that speaker in about 1 full night. Than finally the woofer no sound anymore but the high can sing. What is the problem?

[@JohnB-2021]

Obviously a bass problem, it could be anything.

[@rookystevan5493]

@@JohnB-2021 which parts of it?

[@matthewfrohbieter1803]

So I’m kinda between getting DBR12’s or the electro-voice zlx12’s. If price were equal it would be easy, but i can get the zlx’s for about $80 less. Any suggestions?

[@JohnB-2021]

The Yamaha are many times more powerful, at $80 difference I would never consider anything less than Yamaha. The Yamaha have 2 500 watt driver chips, the ev has a baby driver chip.

[@matthewfrohbieter1803]

@@JohnB-2021, thank you very much for the response.

[@JohnB-2021]

@@matthewfrohbieter1803 Something must have changed because Yamaha's DBR range were hundreds of £ / $ more expensive than the Electro Voice ZLX12 & 15 series. Maybe Yamaha have dropped their prices, if EV have put their prices up they are having a laugh. The design between the 2 is like chalk and cheese or day and night. If EV were hundreds cheaper I would still never buy one. I assume you have seen my EV videos? Thanks for your comments

[@irwaniswadi]

Thanks sir...bisakah anda memberi tahu test point di ic L6599Ad? Di point penting seperti HVG LvG Yang menuju Mosfet 28NM60,Supaya aman dari perbaikan nya..

[@JohnB-2021]

Test the Gates.

[@TheRumpydilo]

Hi John , Like your videos but we may have a problem, That 6.8r resistor is very important , It has a thermal fuse built in @ 142 degrees , The idea is if the switching IGBT's are short circuit then the resistor heats up the blow the thermal fuse open.Rather then blowing traces .

[@JohnB-2021]

Hi, You're forgetting about the 3.15 amp fuse

[@ijasuteja2312]

hi mix ... I have active DBR 12 speakers dead ... how do I use the service ... thank you

[@JohnB-2021]

Hi, I'm too busy to take on extra work, if you're in the UK, you could try Real Electronics.

[@loolou]

Hi John, appreciate the video. I have aqcuired a faulty Yamaha MSR400 speaker that turns on but the sound is very low and seems like its all treble and no bass. After having a fiddle the sound went back to normal after increasing the volume but after connecting it to my electronic drums I think I may have thumped in a very high frequency which has put it back to the faulty sound of no bass and very low volume and only treble. Is the speaker repairable? I'm not sure how to troubleshoot this one. Thanks for your time if you read this and all the best.

[@JohnB-2021]

It could be anything. I had a Mackie speaker doing a similar thing, there was a dry joint for the bass power, the treble was fine.

[@loolou]

@@JohnB-2021 cheers mate I have a feeling it's a bad joint but will have to wait for parts to even open the damn thing

[@loolou]

@@JohnB-2021 Had to come back and thank you as it was just a lose connection with one of the bass joints. All sorted and the speaker is working great. Keep up the great stuff.

[@dr.juanmanuelgonzalez6812]

Hi John, I am writing to you from Mexico I have a Yamaha DBR15 speaker with the same circuit that you repaired in the video, the problem is that they connected 220 volts instead of 110 volts when I checked the resistance of 6.8 ohms at 5 watts (R116 ) It was open and the capacitor from 1mf to 400 volts (C154) presented a hole in the upper part, I changed this two components and it worked, put everything together again leave the speaker working and at half an hour an explosion was heard and the capacitor C154 of 1 mf at 400 volts burst and the diode D126 the D1F60 opened, check the Mosfets Q106 and Q107 and they do not mark me in short circuit, the strange thing is that the speaker sounded when I change the resistance and capacitor and now that it explodes the filter on D126 opened but the 6.3 amp fuse and resistance did not burn, which you think it may be. Help.

[@JohnB-2021]

Hi Juan, I believe the speaker is 110 or 240 volts so 240 should not have been a problem. I'm guessing a diode had gone short circuit causing the capacitors to explode. In the schematic, you will see a dotted line, everything to the left is mains potential. You need to spend an hour checking all the components to the left of the dotted line before plugging it in again. Capacitors only explode with wrong polarity or too high a voltage, a short circuit diode will allow the wrong mains polarity to reach the capacitor. If there are 2 capacitors in series and one goes short circuit, the other will have twice the voltage across it and explode.

[@dr.juanmanuelgonzalez6812]

@@JohnB-2021 thanks you John .

[@karmacadabra9944]

same problem here, I think Yamaha messed up. they have put the wrong fuse in this.

[@JohnB-2021]

@@karmacadabra9944 Quote from Andrea Vico, "Fuse is not made to prevent damage to the electronic circuit. It's not the goal of a fuse. So if the electronic fail the fuse is not the culprit"

[@mikedubz5576]

The dbr Amplifier how does it compared to ev zlx Amplifier? Any thoughts before i choose the company i buy speakers from. I would gate to spend my hard earned money on crapy Amplifiers. My 2 choices are yamaha or electro voice. You opinion matters cause you know what they made with/of.

[@JohnB-2021]

It depends on what EV you're looking at. I would never buy an EV product, just read the comments in my EV videos. Half love them & half hate them.

[@mikedubz5576]

@@JohnB-2021 either the ellx112/115 Or the dbr12 /15 Or Dhr10 /15

[@JohnB-2021]

@@mikedubz5576 I have only seen the ZLX amp and some EV sub I repaired. Similarly, I have only seen the DBR range of Yamaha amps so can’t comment on any others.

[@reyrumbera5689]

Hi John, I have a DXR15. It turns on but no sound comes out of the speaker. Do you think it could be the same problem? Please help thank you.

[@JohnB-2021]

Hi, No this amp I repaired, and never got paid, was totally dead. Sounds like a loss of input if you have no bass or treble.

[@RetroglowSystems]

Hi John, Iam willing to spend around 900 euro`s for a pa speaker system. I wanted to buy the EV zlx-12p but after your video i decided to look for other speakers. Would you recommend the yamaha DBR series? Or should i look for other speakers.

[@letterbase3492]

The dbr are better,also has a high SPL than zlx

[@JohnB-2021]

Yes I think the Yamaha DBR series are great speakers

[@RetroglowSystems]

@@JohnB-2021 Thank you guys for the quick response, i will be saving up for the DBR 12 then. Have a nice day!

[@puskesmaskalideres7165]

Yamaha DBR Are superior than ev ZLX,iam user yamaha DBR...

[@JohnB-2021]

@@puskesmaskalideres7165 Excellent

[@yendizof5309]

Using how many transistor bro ?

[@JohnB-2021]

2

[@adrianahumada7385]

I have an amp like that for a dxr15 that doesn’t power up but if I hit the speaker on a side it turns on sounds like a relay not kicking in but when I hit it sounds like it kicks in and powers up. Any idea what I can check to find my issue?

[@JohnB-2021]

no idea

[@djzak2978]

HI JOHN I have Yamaha Dxr15 it's not turned on

[@JohnB-2021]

Are the Dxr the same as DBR? I assume you mean it’s not turning on. You need an engineer to look at it.

[@djzak2978]

Thanks JOHN BUT HER IN MOROCCO NO ENGINEER TO REPAIR DXR

[@djleonoise2054]

Hello John B, how are you? I don't understand English very much, but I can translate it here on google. I have the following problem in this box dbr15 was replaced the ic101 L6599 the transistors 28NM50 the resistor R 116 of 6.8 ohms. Still the box does not turn on! the rest seems all ok! what to do ? help me please!

[@JohnB-2021]

Impossible to diagnose without seeing it.

[@tiaguinhosanfoneiro8514]

Irmão tô com uma DBR15 queimada, liguei no 220 sem querer e queimou, o mais foda foi que o fusível não protegeu a placa, tô perdido, as assistências não mexem nessa caixa aqui em Salvador.

[@JohnB-2021]

@@tiaguinhosanfoneiro8514 Você precisa de encontrar uma companhia do reparo nos E.U. talvez, o transporte ao Reino Unido custaria uma fortuna. O orador deveria ter trabalhado bem em 220v

[@nilrosewilliam]

@@tiaguinhosanfoneiro8514 ,estou trabalhando em uma que queimou a fonte em 220. estou em Contagem, MG.

[@morritox]

Do you know that audio mosfet use these equipment? regards!

[@JohnB-2021]

IRS2092S & STF19NF20

[@morritox]

@@JohnB-2021 So this does not use transistors for audio power anymore?

[@JohnB-2021]

@@morritox It's a class D, it uses FETs

[@thereflexmobiledisco6700]

My dbr12 just went pop buddy. Are you still repairing these?

[@JohnB-2021]

Sorry, no.

[@loneliboy1234]

I have a yamaha dbr 12, no sound but only some hiss coming from the small speaker, why is that so :(

[@JohnB-2021]

Sounds like the bass is blown up

[@loneliboy1234]

@@JohnB-2021 What can I do to fix this :( it is the same since the day it arrived. I didn't realize this because a decent sound is already coming from the 12" speaker. I didn't even know there were two speakers

[@JohnB-2021]

@@loneliboy1234 I am lost, you said hiss coming from the small speaker and now decent sound coming from the 12" speaker. I would get it checked by someone else first. There is a tweeter and a woofer.

[@loneliboy1234]

@@JohnB-2021 Hi, sorry for misguiding. When ı play something, no mucis is coming from the tweeter. Tweeter only makes some hissy noise. But the woofer work just okay (no hiss whatsoever). The decent sound coming from the woofer unabled me to realize no sound coming from tweeter. Thanks a lot for the help btw :)

[@mattmoreira210]

28:25 "why pick a 105°C there?" BOM reuse? Hard to tell. (Edited, because I didn't like my tone. Came across as a show-off)

[@JohnB-2021]

But all the others are standard temperature caps so there goes your BOM. I build pcbs so I know about BOM and re-using existing parts.

[@quinnvangaalen8654]

Hey John! Thanks for the informative video! I recently dropped one of my Yamaha dbr speakers 🙄😡 now on the low end there is feedback. I have checked all external screws so I believe it's coming through the speaker itself. What should I do/check next? Hope you can help, thanks!

[@JohnB-2021]

You may have caused one of the heavier components on the pcb to become detached or maybe the pcb itself is damaged.

[@RobinHow]

Hi John. I have a DXR12 with a very similar circuit (at least visually it looks so) and the same symptoms - no power, relay doesn't click, 6.15A slow blow fuse intact etc. I've got to the limits of my competence and rather than start faffing about with things I don't fully understand, I'd like to use your services! How do I get hold of you? Cheers.

[@RobinHow]

I'm in the UK by the way.

[@JohnB-2021]

Hi, I'm not repairing amplifiers at the moment but there is a guy on ebay that can look at your amp. www.ebay.co.uk/itm/Mackie-SWA1501-SWA1801-SRM450-Thump-series-servicing-and-repair-specialist/153867355114?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

[@ust4ever1]

Hey John, really interesting video. I've got a set of Yamaha Class D amps (P2500S) which have all got slightly different faults. One of them definitely seems repairable but I'd like to send it to someone who knows what they're doing! Where are you based? Is there a way to contact you?

[@JohnB-2021]

The P series have a tonne of parts and most people will not pay over £100 to have them repaired so I don't bother. I don't think they are class D, I believe they are class B.

[@ust4ever1]

@@JohnB-2021 ah okay that’s a pity! Thanks all the same

[@miamichi5]

Hi Mike ? I'm totally stressing myself out..? Do you recommend the Yamaha dxr over the dbr series...or it's basically the same speakers...dxr has fan in the outer back is that better less likely to get hot..I live in hot humid Florida... heat & humidity is a huge problem...or should I stick to none powered speakers like Peaveys BLK widow speakers...great videos! Thank you! God bless you 🙏.

[@JohnB-2021]

Hi, I'm John I'd recommend any powered speaker by Yamaha or Mackie, not seen the dxr series. Thank you

[@eddypurwanto2607]

bos boleh tuhu no ic pwm berapa

[@JohnB-2021]

Because it's in the chip.

[@DewaStudio]

L6599AD

[@bentopalu2463]

@@DewaStudio makasi harganya brpa bli ic pawer nya

[@garyhunkin]

Agreed, good engineering

[@JohnB-2021]

Great amp but it did go wrong.

[@garyhunkin]

Exceeded SOA for switching FETs. SOA monitoring is missing in most power and amplifier designs. Costs money. Needs to be tuned and tested under all environmental conditions.

[@thenhan_ht9945]

Bo bị cháy ic 100 mong giúp đỡ

[@emersonvella]

ST Microelectronics... made a few km away from where I live in Malta. Didn't realise some of the locally produced components could end up in any of the electronics I use. Its a bit surreal.

[@JohnB-2021]

I didn't know ST Microelectronics had a site in Malta. Thank you for the info.

[@tuantranvan4752]

Hello. I am very happy for your sharing. Can you give me a drawing of it, please?

[@JohnB-2021]

Did you not try searching? It's on the first page. elektrotanya.com/yamaha_dbr10_dbr12_dbr15_sm.pdf/download.html

[@tuantranvan4752]

@@JohnB-2021 thank better very much

[@sadinsadin9249]

Boleh minta pdf nya

[@JohnB-2021]

Google it

[@Noah-gq7pq]

great job man,,,you know your shit,,,,,,,,,,,,thankx

[@JohnB-2021]

I appreciate that!

[@milanoid1]

Скотч не скрыл того, что данный аппарат был для русскоязычного рынка)

[@cbraudio3175]

Ada yang tau nilai R137&136

[@stupid6907]

7ohms

[@marulituahutabarat6285]

@ 10 ohm.

[@karmacadabra9944]

If Yamaha knows what they are doing, is something nasty. I apparentely just lost a $600 speaker because the fuse did not break because is not the right fuse. Shame on you YAMAHA!

[@JohnB-2021]

Karma Cadabra , my video was not intended to make consumers believe they have incorrect fuses fitted. If an internal fuse fails, it is due to a blown component. I simply couldn't understand why they would have a specialised resistor fail instead of a fuse. A fuse is cheaper than a resistor and easier to source too. I guess the resistor failing is to stop end users changing an internal fuse when there is an internal failure. i.e. users of the 450v2 Mackie change internal fuses and plug them back into the mains, this is the wrong thing to do since it causes more damage 99% of the time.

[@andreavico6198]

Fuse is not made to prevent damage to the electronic circuit. It's not the goal of a fuse. So if the electronic fail the fuse is not the culprit.

[@JohnB-2021]

@@andreavico6198 Well put

[@mattmoreira210]

Fuses are last-resort protection devices. I like to think of them as a protection for the user, more than a protection for the circuit.

[@ninjatzuuninjazuu8776]

Don't yamaha offer 7 year warranty on their speakers?

[@MC-01]

What a poor heat disapation engneering

[@MicrosiMe]

You mean, what a smart and efficient heat dissipation system.

[@MC-01]

Now you put into that i think yes nice smart heat dissipation system

[@JohnB-2021]

I thought it was good.

[@zepyutzaputra9029]

made in indonesia

[@JohnB-2021]

Yes. Not bad hey?

[@vaidaadrian-ionut6135]

Hello, can i have your email? I whant to send you a yamaha speaker amplifier for repair.