I'm going to say, up front and on the down low, that this comment is 100% unsolicited by Richard or anyone else but in the interest of Richard and his watchership - all of us - so that we get to enjoy much more of his brilliant content. You (collectively) wouldn't be here if you didn't love Richard's brilliant videos. Naturally, we all hope Richard continues to make them in perpetuity. He does this for our benefit and to some extent, his own too as he's just a small business owner / 1 man content creator show. I'd venture a guess that many of you may be aware that there's a lot that goes on behind the scenes in his videos, as is the case of all quality content YT videos. Richard uses multiple cameras, a scope camera and a cap card, a skill set many may not have (present company included). I'd love to think he's sunny himself on a pristine beach in Gran Canaria, sipping a Jagga Woo Woo while watching belle donne walk the shore (while his wife gives him the evil eye) but in reality, he's got to take a good chunk of his time to put these together. There are multiples way to support LER content: Patreon / donations, sponsors, etc. Another method I found that worked is to purchase a couple motherboards directly from Richard. On one of his 'Car Booty' episodes, Richard came across a, Socket 775 Asus P5E3 Deluxe mb that I'd had my eye on for a some time now. Prior to that, I only saw 1 overzealously priced 1 from China, and a handful of 'Parts Only' ones on eBay. I immediately contacted Richard and we worked out an arrangement that worked for both of use. A similar story goes for an Asus GA-Z77X-UD3H I purchased from him recently; in that case, I could've bought 1 off eBay for a few scheckels less but I saw this one fire up! Sorry this wound up being a 2 volume comment but just a heads up out there for another way to get King Richard to provide more of his brilliant content!
These are my favorite instructional video types .... real world troubleshooting and repair. Rich, your expertise and willingness to pass on your knowledge are greatly appreciated.
Wow this is amazingly informative, thank you! I've got some passive speakers here where the crossover has clearly burned out some resistors in the past. Someone's come along, bypassed the crossover, hot-glued some fat resistors to the horn and wired all that to the main driver. It's very much like the pre-existing repair here. I don't understand it at all yet, but watching your videos I'm gradually working towards having the confidence to start pulling things apart, following the signal path and testing components so I can find and (hopefully) fix the original fault that led to this butchery.
Yes, Mr.Richard I watch yur videos every day.. I like to learn opamp from yu.. You always have different approach in explaining theory with practical stuff.. That is so important , nice to watch ...
Another great video, Richard. I love the systematic approach. Any news on when you plan to do part 2 of the ESR project? I thout your adeas for it were great.
Hi Richard, I suggested some little while ago that you get some means of highlighting you PC cursor for when you are tracing through schematics (and maybe other stuff), so that we can see at a glance where you are looking. It can be very difficult when you refer to "here" & "there" to see the arrow head when motionless and camoflaged against the B&W lines on the page. You seemed to think it was a good idea at the time so hopefully, you will find a solution. Nice big yellow disc please!?! 😁I love listening to you and your thoughts but sight of your thought processes would be even better. TTFN
Yeah you did suggest that, there was some reason why it I couldn't get it to I work at the time but have a different recording setup for windows screen capture using a second PC now so I'll give it another go
Hi Richard. Love the videos and they are a massive help on my learning curve. I have a question. Where is the best place to ask knowledgeable people some specific questions about a repair I’m learning on? I’m a bit stumped around some readings and can’t seem to teach myself out of this hole. I assume there are some good forums etc around?
Heya 5:18 this is what some 1 calls a repair LMBO, yes learned a lot, if it is possible I would like to see some more detailed info about the workings for the differantd upamp's I know by this it's not the fault but I think I still can learn so much from you, but still good stuf loved it
Hi Dicky, can you fix the pointer when doing videos like this, as it’s hard to see where your pointer is on the schematics cheers. Keep up the great work mate 🤙🏼🇦🇺 Joe from Australia 🤙🏼🇦🇺
That previous "repair," obviously done by someone who didn't know anything about amplifiers but could build a makeshift filter, just proves the old Dilbert saying: "A little knowledge is a dangerous thing."
Not so bad, though. This is probably a piezo horn that does not need much of a filter anyway and will be responsive to higher frequencies only (of which there will not be too many due to the separate signal paths). So at least the repair managed to get some noise out of the horn, albeit not as much as desired. And if it is not a piezo, the „filter“ protects it from too much low frequency power. If the LF part had not been filtered, which is a possibility since the LF speaker is its own high pass filter due to its frequency response and the HF could have been diverted to the horn. So it could have worked to some extent if the signal paths had not been separated.
Pretty much mirrors my methods exactly, including never trust the fault explanation, always confirm first. combined with logic, what's easiest/most likely, confusion and luck. In college learning fault finding back when they taught such things the half way search or 50% or binary chop search was a key principle but I often used to carefully look at the component side (which was under an acrylic cover) to see what they had done to create the fault, one method was to file or snap a resistor and then hide it with paint which was noticeable, once I knew that I just went through the motions and quickly "found" the fault. One fault they did introduce was a short circuit resistor which I found weird at the time and I don't think I have ever come across a short circuit resistor in over 30 years.
Interesting...but are we sure that the reason for no tweeter signal wasn't the bodged RC filter across the tweeter coil? If it was R=104 ohms in series with C=3.3uF, and that was in parallel with the tweeter coil (8 ohms), isn't that basically a low pass filter that would filter out midrange and above (-3dB is around 500Hz)? Or am I missing something?
I think the crossover filter was pointless here, since the signal for the bass speaker didn't even have any high frequencies. There were low pass filters on the pre-amp board, I think, which separated the two signals way ahead of this crossover. Am I right?
The dangers of copying stuff of the Internet (or maybe a Chat GPT guess). My guess is that the 100 Ohm was across the woofer, then a 3.3uF (crossover about 6kHz) and 4 Ohm in series the tweeter. Nice (not).
No you are not missing something regards the botched RC filter - if this was ever going to work to any extent then they should have at least bypassed the active low pass filter on the input to the bass amp. What you have missed (apparently) is where I show, using the scope, that there no audio signal going into or out of the tweeter amp at 00:22:30, having already proven a few minutes before that the output power amp chip does have +/- power present
What beats me though is why the trimmer would kill the signal if there is no connection between the wiper and the resistor path. The way it is connected at max. it would be 2k in series with 1.5k of the fixed resistor, which should not fully kill the output signal of the op amp. And a trimmer going open circuit between the 2 fixed ends also sound unlikely. 🤔
Hi Alan, yeah emailed my contact at solderstick.com and asked the question, here is a copy paste: Hi K A subscriber asked my what the maximum voltage (insulation rating) of the solderstick connectors is. Hi Richard,Sorry for the delay in my response. The maximum voltage for this product is 220 volts I guess I am speaking with someone in sales, maybe I should rephrase the question in a more specific manner and ask again?
I have a tv/vcr combo by JVC. I’ve had it many years and had just been using it to make some tapes , but now all of the sudden I can’t load a tape. It won’t accept a tape. The television part still works.
I'm not sure I understand the question. I connected the cables as they were originally, by the colour coding on the cables. Of course someone prevoiusly could have connected the cables to the wrong position on the speaker itself
@@LearnElectronicsRepair Ah sorry, I watched again and can see that the cables have a black stripe to indicate polarity. When I watched first time it looked just like two greens and two blues, with no way to tell polarity. I was worried it would be possible to connect them out of phase so that the output of the tweeter cancelled the output of the woofer.
This speaker, and other bi-amp designs, use active high pass/low pass filter circuits in the mixer section to send the low frequencies to the bass amplifier and the high frequencies to the treble amplifier. Therefore they do not need a crossover circuit (resistors, capacitors, inductors) on the speakers themselves
I would have been compelled to twiddle with the trimmer to see what effect it had and see if the dead spot was still present . PS my heart sank when I spotted the insulation tape
@@tonysheerness2427 Which is why I mentioned in the video that these types of components (switch.potentiometer/connector) are ones you should always suspect first with this sort of fault. I guess I still have quite a lot of videos to make 🙂
I WANT TI SUPPORT YOUR VIDS AND ADD 100K SUBS. AND U ASKED IF YOU CAN GET THE BEEP QIETER AND YOU HAVENT YET. CAN YOU PLEASE TRY. JUST TRY TO GET THE BEEP QUIETER. IF NOT I JUST CANT WATCH ITS KILLIKNG US. I WATCH WITH THE 100K PEOPLE WATCHING WITH ME. THANKS
Joey, Do you think you are defeating your own argument regards the apparently excessive volume on my multimeter continuity test by SHOUTING about it in the comments here? I mean just logically thinking about it, that seems counterproductive 😵💫 Is my multimeter too loud compared with other YT channels or meters? Is this an issue with certain viewers audio (listening )setup? Are a lot of you having a big problem with this? Does it just make sure you stay awake during my long videos? And was that a 'Killers' quotation? Oh actually no. That's 'I just Can't Look It's Killing Me' sorry
No issue whatsoever for me regarding the multimeter. Surely it’s an essential part of touching/feeling and hearing during the fault finding process. And sadly people moaning on the comments is just a bore we have to all suffer!
Get Solderstick at 20% OFF with discount code "RICHARD20" at www.solderstick.com/sale
How do you do for don`t have gnd prove attach on you osciloscope? Thanks...
@@skysurfhf he had one probe grounded. The other probe gets grounded via the scope that way. 😎
I'm going to say, up front and on the down low, that this comment is 100% unsolicited by Richard or anyone else but in the interest of Richard and his watchership - all of us - so that we get to enjoy much more of his brilliant content.
You (collectively) wouldn't be here if you didn't love Richard's brilliant videos. Naturally, we all hope Richard continues to make them in perpetuity. He does this for our benefit and to some extent, his own too as he's just a small business owner / 1 man content creator show.
I'd venture a guess that many of you may be aware that there's a lot that goes on behind the scenes in his videos, as is the case of all quality content YT videos. Richard uses multiple cameras, a scope camera and a cap card, a skill set many may not have (present company included). I'd love to think he's sunny himself on a pristine beach in Gran Canaria, sipping a Jagga Woo Woo while watching belle donne walk the shore (while his wife gives him the evil eye) but in reality, he's got to take a good chunk of his time to put these together.
There are multiples way to support LER content: Patreon / donations, sponsors, etc. Another method I found that worked is to purchase a couple motherboards directly from Richard. On one of his 'Car Booty' episodes, Richard came across a, Socket 775 Asus P5E3 Deluxe mb that I'd had my eye on for a some time now. Prior to that, I only saw 1 overzealously priced 1 from China, and a handful of 'Parts Only' ones on eBay. I immediately contacted Richard and we worked out an arrangement that worked for both of use. A similar story goes for an Asus GA-Z77X-UD3H I purchased from him recently; in that case, I could've bought 1 off eBay for a few scheckels less but I saw this one fire up!
Sorry this wound up being a 2 volume comment but just a heads up out there for another way to get King Richard to provide more of his brilliant content!
Agree, thank's for what You're doing for us Richard :)
I'm a patreon, have been since I discovered the channel.
These are my favorite instructional video types .... real world troubleshooting and repair. Rich, your expertise and willingness to pass on your knowledge are greatly appreciated.
Wow this is amazingly informative, thank you! I've got some passive speakers here where the crossover has clearly burned out some resistors in the past. Someone's come along, bypassed the crossover, hot-glued some fat resistors to the horn and wired all that to the main driver. It's very much like the pre-existing repair here. I don't understand it at all yet, but watching your videos I'm gradually working towards having the confidence to start pulling things apart, following the signal path and testing components so I can find and (hopefully) fix the original fault that led to this butchery.
You re great!
Finally Someone who can teach how to faultfinding in real life
thank you
greetings from Italy
....'I'm gonna make a video on Op-amps...'. I look forward to that one too! :)
Sincere thank you for another great addition to your growing, wonderful legacy of passing on knowledge.
Great video - and while I never really work on audio gear your techniques definitely taught me something.
Thank you for your generosity in sharing.
Yes, Mr.Richard I watch yur videos every day.. I like to learn opamp from yu..
You always have different approach in explaining theory with practical stuff..
That is so important , nice to watch ...
Another great video, Richard. I love the systematic approach. Any news on when you plan to do part 2 of the ESR project? I thout your adeas for it were great.
Yeah I've been doing quite a bit of work on that with Detlef, expect to see something soon-ish
It was great seeing you go through your troubleshooting process. Much thanks for making these videos!
HI Richard, Loved the video, very informative. I liked it so much that I subscribed....Keep up the good work.
Hi Richard, I suggested some little while ago that you get some means of highlighting you PC cursor for when you are tracing through schematics (and maybe other stuff), so that we can see at a glance where you are looking. It can be very difficult when you refer to "here" & "there" to see the arrow head when motionless and camoflaged against the B&W lines on the page.
You seemed to think it was a good idea at the time so hopefully, you will find a solution. Nice big yellow disc please!?! 😁I love listening to you and your thoughts but sight of your thought processes would be even better. TTFN
Agree, there are some included markup tools for pdf's, jpg's etc and although some are fiddly to use, they would enrich the learning experience.
Yeah you did suggest that, there was some reason why it I couldn't get it to I work at the time but have a different recording setup for windows screen capture using a second PC now so I'll give it another go
@@LearnElectronicsRepair Cheers my man!
Ciao for now.
Hi. Could you use a bigger and negatively translucent pointer? It would make it a lot clearer when you're directing our eye around a schematic.
Hi Richard. Love the videos and they are a massive help on my learning curve. I have a question. Where is the best place to ask knowledgeable people some specific questions about a repair I’m learning on? I’m a bit stumped around some readings and can’t seem to teach myself out of this hole. I assume there are some good forums etc around?
I have a class D power amp and boy it has power and is very very efficient and is the best sounding amp i have ever had .....
Heya 5:18 this is what some 1 calls a repair LMBO, yes learned a lot, if it is possible I would like to see some more detailed info about the workings for the differantd upamp's I know by this it's not the fault but I think I still can learn so much from you, but still good stuf loved it
Great video! Thanks!
Hi Richard, please would you do a video explaining how op amps work?
yes please
Awesome video and a great troubleshooting process! Thanks for the video!
Hi Dicky, can you fix the pointer when doing videos like this, as it’s hard to see where your pointer is on the schematics cheers. Keep up the great work mate 🤙🏼🇦🇺
Joe from Australia 🤙🏼🇦🇺
Great video
previous repair attempt was some sort of Sorin style. but great job. these solder sticks are very useful for that kind of repairs
That previous "repair," obviously done by someone who didn't know anything about amplifiers but could build a makeshift filter, just proves the old Dilbert saying: "A little knowledge is a dangerous thing."
Not so bad, though.
This is probably a piezo horn that does not need much of a filter anyway and will be responsive to higher frequencies only (of which there will not be too many due to the separate signal paths). So at least the repair managed to get some noise out of the horn, albeit not as much as desired. And if it is not a piezo, the „filter“ protects it from too much low frequency power.
If the LF part had not been filtered, which is a possibility since the LF speaker is its own high pass filter due to its frequency response and the HF could have been diverted to the horn.
So it could have worked to some extent if the signal paths had not been separated.
Pretty much mirrors my methods exactly, including never trust the fault explanation, always confirm first. combined with logic, what's easiest/most likely, confusion and luck. In college learning fault finding back when they taught such things the half way search or 50% or binary chop search was a key principle but I often used to carefully look at the component side (which was under an acrylic cover) to see what they had done to create the fault, one method was to file or snap a resistor and then hide it with paint which was noticeable, once I knew that I just went through the motions and quickly "found" the fault. One fault they did introduce was a short circuit resistor which I found weird at the time and I don't think I have ever come across a short circuit resistor in over 30 years.
Good job
Interesting...but are we sure that the reason for no tweeter signal wasn't the bodged RC filter across the tweeter coil? If it was R=104 ohms in series with C=3.3uF, and that was in parallel with the tweeter coil (8 ohms), isn't that basically a low pass filter that would filter out midrange and above (-3dB is around 500Hz)? Or am I missing something?
Oh wait, nevermind. The R=104 ohms was also in parallel with the 8 ohm tweeter coil, so the filter really wouldn't have any effect.
I think the crossover filter was pointless here, since the signal for the bass speaker didn't even have any high frequencies. There were low pass filters on the pre-amp board, I think, which separated the two signals way ahead of this crossover. Am I right?
The dangers of copying stuff of the Internet (or maybe a Chat GPT guess). My guess is that the 100 Ohm was across the woofer, then a 3.3uF (crossover about 6kHz) and 4 Ohm in series the tweeter. Nice (not).
No you are not missing something regards the botched RC filter - if this was ever going to work to any extent then they should have at least bypassed the active low pass filter on the input to the bass amp. What you have missed (apparently) is where I show, using the scope, that there no audio signal going into or out of the tweeter amp at 00:22:30, having already proven a few minutes before that the output power amp chip does have +/- power present
@@mik13ST Totally correct 🙂
32:01 Crown! Makes sense because it's the amplifier company of Harman, the parent company of JBL (yes, I know Harman is owned by Samsung nowadays).
What's the model of oscilloscope you used in this?
Great video
What beats me though is why the trimmer would kill the signal if there is no connection between the wiper and the resistor path. The way it is connected at max. it would be 2k in series with 1.5k of the fixed resistor, which should not fully kill the output signal of the op amp.
And a trimmer going open circuit between the 2 fixed ends also sound unlikely.
🤔
Hi Richard, did you manage to establish the rated voltage grade of the solderstick insulation material
? 😁
Hi Alan, yeah emailed my contact at solderstick.com and asked the question, here is a copy paste:
Hi K
A subscriber asked my what the maximum voltage (insulation rating) of the solderstick connectors is.
Hi Richard,Sorry for the delay in my response. The maximum voltage for this product is 220 volts I guess
I am speaking with someone in sales, maybe I should rephrase the question in a more specific manner and ask again?
@@LearnElectronicsRepair I'm guessing it's much higher than that, at least 10 times that, has to be.
What oscilloscope is that?
This one was a simple problem, requiring a thorough check.
I have a tv/vcr combo by JVC. I’ve had it many years and had just been using it to make some tapes , but now all of the sudden I can’t load a tape. It won’t accept a tape. The television part still works.
Just curious. 1:03:00. Don't you have to take care that woofer and tweeter cables are in phase? The colour-coding doesn't seem to help with that.
I'm not sure I understand the question. I connected the cables as they were originally, by the colour coding on the cables. Of course someone prevoiusly could have connected the cables to the wrong position on the speaker itself
@@LearnElectronicsRepair Ah sorry, I watched again and can see that the cables have a black stripe to indicate polarity. When I watched first time it looked just like two greens and two blues, with no way to tell polarity. I was worried it would be possible to connect them out of phase so that the output of the tweeter cancelled the output of the woofer.
@@robjordan63 I was thinking exactly the same!
I would like to see an SD card electronics repair(video). One SD card that is not recognized any more in computer.
I just wonder if the tweeter would be blown by not having a capacitor to block out the low frequency signals.
This speaker, and other bi-amp designs, use active high pass/low pass filter circuits in the mixer section to send the low frequencies to the bass amplifier and the high frequencies to the treble amplifier. Therefore they do not need a crossover circuit (resistors, capacitors, inductors) on the speakers themselves
My ex was really good at methodical fault-finding.
Could Be the TDA package
I would have been compelled to twiddle with the trimmer to see what effect it had and see if the dead spot was still present .
PS my heart sank when I spotted the insulation tape
VR1 is missing too
Disconnect the tweeter first to determine whether the tweeter or the woofer is kaput
Had that problem was a open voice coil tweeter. There is always some asswhole out modifying equipment keeps real Techs working
PSU all Ok - Work from in to out OR Out to in You will soon find the OC point.
😊
Northern Soul? You a shuffle dancer then?
I've had my moments 😉
Send lower freq to tweeter will damage the tweeter in my experience
That's why the capacitor was fitted.
If the speakers were used as they should the only things that could go wrong are mechanical devices like the trimmer pot.
Yeah pretty much that. Switches, potentiometers (and connectors) are the most likely culprits in this sort of fault scenario
@@LearnElectronicsRepair Well done, however learning to do what you do takes decades. Looking at circuits and how they work is not easy.
@@tonysheerness2427 Which is why I mentioned in the video that these types of components (switch.potentiometer/connector) are ones you should always suspect first with this sort of fault. I guess I still have quite a lot of videos to make 🙂
the customer must have been pranking you...
Unfortunately not, this sort of 'repair job' is common here
Tweeter amp is my guess without watching the vid....
Comment for the gods
Can't get by the dialect. Ugh.
I WANT TI SUPPORT YOUR VIDS AND ADD 100K SUBS. AND U ASKED IF YOU CAN GET THE BEEP QIETER AND YOU HAVENT YET. CAN YOU PLEASE TRY. JUST TRY TO GET THE BEEP QUIETER. IF NOT I JUST CANT WATCH ITS KILLIKNG US. I WATCH WITH THE 100K PEOPLE WATCHING WITH ME. THANKS
Joey, Do you think you are defeating your own argument regards the apparently excessive volume on my multimeter continuity test by SHOUTING about it in the comments here? I mean just logically thinking about it, that seems counterproductive 😵💫
Is my multimeter too loud compared with other YT channels or meters?
Is this an issue with certain viewers audio (listening )setup?
Are a lot of you having a big problem with this?
Does it just make sure you stay awake during my long videos?
And was that a 'Killers' quotation? Oh actually no. That's 'I just Can't Look It's Killing Me' sorry
RIP Calculon.
No issue whatsoever for me regarding the multimeter. Surely it’s an essential part of touching/feeling and hearing during the fault finding process. And sadly people moaning on the comments is just a bore we have to all suffer!