The bridge mode explanation is great. You can calculate from your example that the same current would be drawn by the speaker if it's impedance was halved, or 2 Ohms (14.5A.) This is exactly the reason why it's said that an amp "sees" half the impedance when you bridge. It's because the current is doubled for the same impedance when it's bridged. Love your explanation of this concept that's completely lost on many people.
Hello there happy New years by far the best video I have ever seen in my whole life the way you draw out the amp board circuits and the way you explain what they are and how they work hands down you are the best teacher and I've learned a lot from your videos keep up the good work God bless you
Hip Hip... Huuurrrreeeyyy! 🥳 Amazing video Richard Sir 🙏🏻 kudos to your work and your reverse engineering. I’ve learned a lot from your videos ❤️ many love for you from India 🇮🇳❤️❤️❤️
In my house that is called a "Man Look". "It is NOT in there!"... Reaches in a takes out the thing directly in front of you... This is a "Man Look"... Appreciate the video, The 66309b just turned up. I'll catch the end of this after I swap the fan for something less crazily noisy :) Hope you are well today
great video Richard I especially liked the explanation using the photograph of the circuit then drawing on the photograph with multicoloured lines really helped me to see what you were saying and it was a lot easier to follow and understand. I think this would be a great teaching aid in future videos. as it's more visual. when testing an unknown amplifiers, is it a good thing to check to see if there is any DC on the speaker output terminals before connecting the speakers to the amplifier, this would save blowing the speakers. would just doing a resistance check eliminate the need to check for DC?
You are correct testing for DC offset on the speaker output is a good technique. I didn't do it on this video but really I should have done. I'll remember that for the next one, Re the drawing on the photo, yeah my wife bought me a digitizing tablet/pen for my birthday - so expect to see more of this teaching technique in future
I love your videos, and as a Learner I loved the use of the colored drawing on the video to explain The use of the amplifier sections, It would be great if you use this method in future videos on the amplifiers.
This is a new toy I have, my wife bought me a digitizing pen/tablet for my birthday and I thought it would be a great tool for use in my videos. it seems i was right, so I will definitely be using it more in future 😁
Love these videos and agree with OP that the colour annotations are super helpful in visualising what’s going on. I’d find it really helpful if you did this early on in a video to explain the blocks you “see” on the boards. This is the 250th video of yours I’ve watched and I am starting to recognise the blocks for myself now - thanks so much Rich
i'd love to send you a few blown amplifiers in different classes if you want to open and fault find them. i dont mind if they dont come back but it would be nice to learn about the different scenarios and their solutions.
great great!!! work you are doing, the theory and practical point of view is so excellent, keep up the great work, thanks you for being such a great inspiration in the world of electronics.
I have 1 of them at home here. I was going to the parts inside for other projects but I think il keep it now.(to be honest I completely forgot I had ot until i saw this video) it's working perfectly and I was going to pull it apart just for a few Op-Amps and relays. (Stupid silly me 🤪) glad I saw this video coz I think i'll sell it now. 💶😁🤑🥳
Yeah I did figure on my quick version of how it could be wired up, that it was not really accurate as I mentioned in the video. I did wonder about changing that but then, really I'm trying to teach the technique of reverse engineering unknown circuits and in reality that usually means getting it wrong at first, or kinda knowing what you have is not quite right but realising it is close enough for what you are trying to repair. 😉
Hello! can you help me? I have a problem with one of amplifier, sine wave output is in the noise (noise is 0,520v wthout any signal) (replacing change amps can (but too cant) help for a moment with clean sine wave, but after 1-5 minutes sine is back to noised sine wave. What is causing this problem? RCa input is clean. After my test with third amplifier, for a moment i got better sine wave in second amplifier, The problem: Amp blowing speaker much before distortion output, bass is weak / weird, flexing car but i dont hear and fell presure, Wave sine on out amp is rippling like Phase reverse - back normal - reverse - back normal itp. In warm temperature sound (bass) can be much better for a few minutes only. Or sometimes multipe disconect power wires can help back clear sine wave Which issue fits this problem? Input noise, Resistor noise, Thermal drift. And how to solve this problem. Thanks!
Regarding the PSU section: Can anyone explain to me where the AC voltage to the transformers comes from? Since it's a car amp it would have DC power coming in; We are talking about rectifying the current coming out of the transformers, so how does it become AC in the first place? Thanks!
Yeah I know about Barevids and I'm a subscriber - for the rest of you reading, this barevids guy is something of a guru on car amplifier repair. We never spoke and I doubt he knows of me but I'd be happy to collab with him anytime. Definitely one of the good guys. I'll try to catch hold of him when he does another live stream and see if he's interested. For anyone learning car audio repair I would recommend you check out barevids youtube channel ua-cam.com/users/barevids
Hi, I have a question for you, I have a 1.4 lt diesel fiesta, long story short, it has 4 glow plugs 11v each, they are connected in parallel, the new ones I have, have 1,8 ohms resistance on each, if they're connected in parallel, ie 4x 1.8 ohms what reading should I get with my ohms meter, would it read high or low resistance when measuring all 4 in parallel?
I love the layout of that amp i have never come across one like it. The ones i hate are the ones that come in with the faut wont come out of protection and there are no shorted output or psu power devices . i am shore there is a simple logical way to fault find but i have not found it. i only look at them as a favour for freinds but am considering saying no . i want keep what little hair i have left.
@rob titheridge I actually have a 600W powered mixer on my bench right now (and video in progress) with exactly that problem. I haven't quite got to the bottom of it yet, but I will publish the video next week one way or the other even if I can't fix it.
Hi Richard I think your schematic is wrong. You draw the schematic of a buck converter, but the amp has a boost converter. The difference is, that in a boost converter the current goes into the magnet and then to the switch. But in a buck converter, the current goes in to the switch and then to the magnet. They do not have the same block diagram...
The power supply fet are not drawn correctly and also the rectifiers but because of his first time doing a car amplifier I can understand his mistakes but good attempt still
It's hard to get into the rhythm of your explaining\teaching, when every minute I am confronted by an add block the view of the PC board that you are exploring! Too many ads.
That is nothing to do with me, it is YT who put the ads in my videos as they choose. Try UA-cam Premuim (free trial). Not only do you get the videos ad free, I also get a paid commission for every video of mine you watch. That's kinda win win yeah? ua-cam.com/video/SJ9wr5ctJiA/v-deo.html I didn't actually watch this video so can't vouch for it's usefulness.
39:08
The rectifier diodes are not actually connected in this configuration but it does not affect the overall description of the circuit operation
Am from KENYA 🇰🇪 I really love your videos... I appreciate your understanding in electronics and the way you teach.. Thank you so much
peace.
🇰🇪🇰🇪🇰🇪🇰🇪🇰🇪
You sir, are a dying bread. I love you videos and your logical progression.
I’m from Grenada in the Caribbean. thanks that was some great explanation Man.Would love to see more amplifier repair videos
The bridge mode explanation is great. You can calculate from your example that the same current would be drawn by the speaker if it's impedance was halved, or 2 Ohms (14.5A.) This is exactly the reason why it's said that an amp "sees" half the impedance when you bridge. It's because the current is doubled for the same impedance when it's bridged. Love your explanation of this concept that's completely lost on many people.
Loud & clear ! since I met your channel i learned a lot . Thanks anyways. Keep itup !!
Thanks for sharing the knowledge, one of the best videos i ever seen .
Hello there happy New years by far the best video I have ever seen in my whole life the way you draw out the amp board circuits and the way you explain what they are and how they work hands down you are the best teacher and I've learned a lot from your videos keep up the good work God bless you
Hip Hip... Huuurrrreeeyyy! 🥳 Amazing video Richard Sir 🙏🏻 kudos to your work and your reverse engineering. I’ve learned a lot from your videos ❤️ many love for you from India 🇮🇳❤️❤️❤️
In my house that is called a "Man Look". "It is NOT in there!"... Reaches in a takes out the thing directly in front of you... This is a "Man Look"...
Appreciate the video, The 66309b just turned up. I'll catch the end of this after I swap the fan for something less crazily noisy :) Hope you are well today
I think you mean "ǝᴉɥɔᴉɹ lǝuoᴉ˥ ʎq ƃuᴉlᴉǝɔ ǝɥʇ uo ƃuᴉɔuɐp" ;)
I am new to your videos and am sold. Going to watch many more and hope to learn much.
Your videos are a wonderful resource for learning electronics… thanks!
great video Richard I especially liked the explanation using the photograph of the circuit then drawing on the photograph with multicoloured lines really helped me to see what you were saying and it was a lot easier to follow and understand. I think this would be a great teaching aid in future videos. as it's more visual.
when testing an unknown amplifiers, is it a good thing to check to see if there is any DC on the speaker output terminals before connecting the speakers to the amplifier, this would save blowing the speakers. would just doing a resistance check eliminate the need to check for DC?
You are correct testing for DC offset on the speaker output is a good technique. I didn't do it on this video but really I should have done. I'll remember that for the next one,
Re the drawing on the photo, yeah my wife bought me a digitizing tablet/pen for my birthday - so expect to see more of this teaching technique in future
Love your videos covering various consumer electronics 👍
I love your videos, and as a Learner I loved the use of the colored drawing on the video to explain The use of the amplifier sections, It would be great if you use this method in future videos on the amplifiers.
This is a new toy I have, my wife bought me a digitizing pen/tablet for my birthday and I thought it would be a great tool for use in my videos. it seems i was right, so I will definitely be using it more in future 😁
Love these videos and agree with OP that the colour annotations are super helpful in visualising what’s going on. I’d find it really helpful if you did this early on in a video to explain the blocks you “see” on the boards. This is the 250th video of yours I’ve watched and I am starting to recognise the blocks for myself now - thanks so much Rich
Great Video, on a subject that's new to my electronics skills, I've build some amplifiers many years ago. Keep up the good work.
i'd love to send you a few blown amplifiers in different classes if you want to open and fault find them. i dont mind if they dont come back but it would be nice to learn about the different scenarios and their solutions.
great great!!! work you are doing, the theory and practical point of view is so excellent, keep up the great work, thanks you for being such a great inspiration in the world of electronics.
I have 1 of them at home here. I was going to the parts inside for other projects but I think il keep it now.(to be honest I completely forgot I had ot until i saw this video) it's working perfectly and I was going to pull it apart just for a few Op-Amps and relays. (Stupid silly me 🤪) glad I saw this video coz I think i'll sell it now. 💶😁🤑🥳
Great job. Greets from germany.
Richard, You are awensome!
Another informative video 👍
Heya oh yes seeing and understanding everything after your explanation thank you so much
Nice video, the PSUs in these are usually push-pull on the primaries
Yeah I did figure on my quick version of how it could be wired up, that it was not really accurate as I mentioned in the video. I did wonder about changing that but then, really I'm trying to teach the technique of reverse engineering unknown circuits and in reality that usually means getting it wrong at first, or kinda knowing what you have is not quite right but realising it is close enough for what you are trying to repair. 😉
another great video, are you planning to do video about using oscilloscope to fix electronics?
I sometimes use oscilloscopes in my videos but when I can I try to teach how to repair items with basic equipment
lovely cover
Love the repair videos, thanks... Can you make a video of repairing inverters since more and more people are switching over to solar installations😆
GOOD VIDEO
Hello! can you help me?
I have a problem with one of amplifier, sine wave output is in the noise (noise is 0,520v wthout any signal) (replacing change amps can (but too cant) help for a moment with clean sine wave, but after 1-5 minutes sine is back to noised sine wave.
What is causing this problem? RCa input is clean. After my test with third amplifier, for a moment i got better sine wave in second amplifier, The problem: Amp blowing speaker much before distortion output, bass is weak / weird, flexing car but i dont hear and fell presure, Wave sine on out amp is rippling like Phase reverse - back normal - reverse - back normal itp. In warm temperature sound (bass) can be much better for a few minutes only. Or sometimes multipe disconect power wires can help back clear sine wave
Which issue fits this problem?
Input noise, Resistor noise, Thermal drift. And how to solve this problem. Thanks!
Regarding the PSU section: Can anyone explain to me where the AC voltage to the transformers comes from? Since it's a car amp it would have DC power coming in; We are talking about rectifying the current coming out of the transformers, so how does it become AC in the first place? Thanks!
Excellent explication!!!!!!
Thanks!!
We need some BAREVIDS and LEP collabs! Both in the UK and both very smart guys!
Yeah I know about Barevids and I'm a subscriber - for the rest of you reading, this barevids guy is something of a guru on car amplifier repair. We never spoke and I doubt he knows of me but I'd be happy to collab with him anytime. Definitely one of the good guys. I'll try to catch hold of him when he does another live stream and see if he's interested.
For anyone learning car audio repair I would recommend you check out barevids youtube channel
ua-cam.com/users/barevids
That old school Hertz looks similar to Earthquake's PowerHouse series.
(the green color ones)
very informative........😍
Hi, I have a question for you, I have a 1.4 lt diesel fiesta, long story short, it has 4 glow plugs 11v each, they are connected in parallel, the new ones I have, have 1,8 ohms resistance on each, if they're connected in parallel, ie 4x 1.8 ohms what reading should I get with my ohms meter, would it read high or low resistance when measuring all 4 in parallel?
should read lower in parallel
The only thing I can add right now is that normally multi channel amplifiers are normally A/B with the D class normally single channel for subwoofers.
What you just stated WAS accurate. But that's not the case any more.
Not even close.
Do one on the old Carver car amp.
These are the big stinky boxes that wake you up at 3am going buuuuuuu buuuuuhhhhh bbbbbooooo buuuuuhhhh a block away
30:41 - could you have used an octopus and lizard juice patterns to understand these connections sooner?
43:29 7915 and 7815 directly from the transformer windings (AC)? I think you forgot the diodes.
Most of them I have repaired had trouble in the PSU. Often they were installed with power or ground wires too small.
I have a pdx alpine 1100 amplifier as I installed it cuts in and out , anyone know how to get it fixed I’m in canada thanks
New Video... Woohoo! let's Go!
Oh for sure I think you are gonna like this one!!
How to trace a fault if everything is good except one channel doesn't work ?
Do You have a yt music playlist with the music You use for testing amplifiers?
I don't
But it sounds like a good idea - I'll do it 😁
sounds like a earth hum on that amp . Could that be a power supply problem or just my old ears?
I love the layout of that amp i have never come across one like it.
The ones i hate are the ones that come in with the faut wont come out of protection and there are no shorted output or psu power devices . i am shore there is a simple logical way to fault find but i have not found it.
i only look at them as a favour for freinds but am considering saying no . i want keep what little hair i have left.
@rob titheridge
I actually have a 600W powered mixer on my bench right now (and video in progress) with exactly that problem. I haven't quite got to the bottom of it yet, but I will publish the video next week one way or the other even if I can't fix it.
Hi Richard I think your schematic is wrong. You draw the schematic of a buck converter, but the amp has a boost converter. The difference is, that in a boost converter the current goes into the magnet and then to the switch. But in a buck converter, the current goes in to the switch and then to the magnet. They do not have the same block diagram...
The power supply fet are not drawn correctly and also the rectifiers but because of his first time doing a car amplifier I can understand his mistakes but good attempt still
If you are not using it any more can you please send it to . Please and thanks.
Hertz is actually a very good brand of amp. Very pricy. You got a great deal at 15 Euros.
Any chance you can fix your microphone next 😀🎤
HEY mate! Do you want to sell this Amplifier?
It's hard to get into the rhythm of your explaining\teaching, when every minute I am confronted by an add block the view of the PC board that you are exploring! Too many ads.
That is nothing to do with me, it is YT who put the ads in my videos as they choose. Try UA-cam Premuim (free trial). Not only do you get the videos ad free, I also get a paid commission for every video of mine you watch. That's kinda win win yeah?
ua-cam.com/video/SJ9wr5ctJiA/v-deo.html
I didn't actually watch this video so can't vouch for it's usefulness.
I thought queer electrons blow all the fuse's? lol
You will just have to pay more next time and get a broken one. 😁
I'm going to try again tomorrow at the car boot sale! 😆
@@LearnElectronicsRepair You don't want a car boot sale - you want a broken car boot sale !