Well, as the owner of this repair, I can’t tell you how appreciative I am. Not only are you knowledgeable on the subject matter, you explain the problem and solution with ease and with a simplicity that is the mark of a pro. Professionals make complexity and hard work appear easy. Never be fooled. If difficult things look easy, it’s because the presenter works harder than most. If you ask anyone that played sports or worked with the worlds best, they all say one thing. They worked harder than anyone I know. Thank you Ray for what you do and for sharing what you do in a way that benefits the world. Thanks so much!
Thanks so much for the kind words, Larry! I've often said the same thing about Ray Dalio. His video "How the Economic Machine Works" takes a complex topic and makes it easily understandable.
Thanks for posting this, I bought 2 used 1091 mono versions of this amplifier. I really the efficiency and light weight of them. They operate so barely warm. Nice to see an easy fix for this issue 👍
I was grateful that the relays were the only issue since there are no schematics for the power modules. They are a revolutionary design, and despite what audio purists may say, they're excellent performers.
Nice work, Ray. Making the jump over from working on vintage gear to more contemporary stuff has been a bit challenging for me so it's nice to see some of these repairs.
I hear you. I've been watching a lot of Louis Rossmann videos, girding my loins for SMD work. Inevitably I'll have to learn to work with it. Thanks for the kind words!
Ray is a Telecom tech, and I myself being a retired one, knows that, the life in that work field revolves around acronyms, probably as bad as the military if not worse.
Thanks Ian! I realized after I posted the video that I should have mentioned that the ultrasonic products seen on the scope were lower amplitude than they actually are, due to the autoranging on the distortion analyzer.
Class D is actually pretty simple stuff. The first thing to note is that the "D" does not mean Digital... it was simply the next available letter after A, B, AB, C. At no time is the audio input signal digitized. The best analogy is to FM radio ... there you are taking an audio signal and encoding it onto a high powered carrier signal. In FM that is done by changing the frequency of the carrier wave, but In Class D it is done by changing the width of square wave pulses (i.e Pulse Width Modulation) Now in FM receivers you tune into the carrier frequency, then remove the carrier to get the audio back. In Class D you are doing much the same thing... Filter out the PWM carrier and you are left with a greatly amplified copy of the original audio signal. As Ray pointed out, this gives us a light, small and very powerful amplifier. Modern versions are implemented on chips like the TPA3255 and TDA7498. When properly powered and filtered they will produce hundreds of watts from a box that sits in the palm of your hand, with sound quality to rival many of the "audiophile" world's monster amps.
That was so gracious of you to share your expertise with the community. Can you post the part number and where we can purchase them. That would be most appreciated. Thank you and God bless you!
Thank you so much for the kind comments! The original relay numbers are obsolete, but the current one is Omron OZ-SS-112LM1, 200. It appears to be electrically and dimensionally identical. May simply be lead free. In any event, they fit perfectly and worked well. They can be purchased from Mouser or Digikey.
Hi Ray, it's been about five years since I repaired a control board for a friend from his heater and water heater, which had, among other things, a faulty relay for switching the turbo. The original relay is normally available for purchase, but I made a reduction printed circuit board and replaced it with a completely different relay that had a higher load capacity of the contacts when switching the inductive load, if I only replaced the relay with the same type, the fault would repeat itself. So I found another relay of a completely different design with the same current requirement of the coil (so as not to damage the switching transistor), but with a many times greater load on the contacts for switching the inductive load - since the replacement, the defect has not manifested itself. I have no idea if it is the manufacturer's intention that the relay breaks down after a certain period of time and you have to buy a quite expensive control board (authorized repairmen solve this only by replacing the control boards), or it is a bad suggestion from the board manufacturer. Nice day 🙂 Tom
@@raygianelli3612 Well, I don't think so, the original relay costs more than the one I replaced it with, in my opinion it is an intention to limit the service life, or a mistake in the design of the control board.
@@justinnitsuj7041 Well, like so many other things in life, you do need checks and balances. Left to their own devices, engineers would design wonderful devices that no one could afford.
Nice repair!…of an evident design flaw. Both amplifier modules have capacitors to be charged, a soft start with a thermistor and relays would have been the right choice for this amplifier, in my opinion. 500+ watts are a lot! Beautiful distortion analyzer and dummy load that can handle it 👍
Those modules are so popular with pro-audio because they are both power supply and amplifier on one board. The higher powered B&O ICEPower modules include soft start on their own power supply boards.
Strongly agree about a soft start! Even with the "spark killer" capacitors across the relay contacts they didn't make 20 years, when much of the vintage gear I see is twice that age and usually still going strong. Those dummy loads sing under high load, but they're rated at 1,000 watts. Most I've pushed through them is 650.
@@andymouse You're welcome. Distortion always rises somewhat right before clipping, then, of course when it does clip the distortion climb is almost vertical. Considering the amp's age (2005) and the state of Class D at that time, it did pretty well.
As ever, great job done, Ray. I'm in Madrid, Spain, and I'm looking to buy a Levear like yours. It's an execellent piece of gear to have everything toghether, specially THD+PW. Could you tell me or recommend me some place apart from EBay to obtain a good state, second hand unit?. Thanks in advance.
They aren't easy to find outside of Asia. A friend who has a TH-cam channel found his on eBay. There are other measurement systems out there as good or better. Occasionally you can find an Audio Precision unit that won't break the bank. Quant Asylum has an interesting software based system with dedicated hardware that's worth looking at. At the end of the day you need to evaluate your needs and find a solution that best fits those needs.
@@raygianelli3612thanks a lot for your answer. I thought so: Japanese market. I have a friend there (the one from NFM TH-cam channel). He’s living in Japan. Maybe he can find out something. I send you a big hug from Madrid.
Ray, did you check the value of C102 & C103? A failure of those could cause the contacts to arc more than they should on power up & down, shortening the relays life. As I mentioned in a reply to douglas_blake_579, I also wonder if this unit wouldn't benefit from some sort of "AC power soft start" addition to take the stress off of the relay when first powering on.
The capacitors measured OK, but who's to say they're not breaking down at higher voltages? After giving it some thought, I don't think a soft start would help in this case. I believe that the contact arc when they open on amplifier shutdown.
@@raygianelli3612 It would be interesting, but also time consuming , to, do some sort of scope capture of the voltage across the contacts when "powering down" a few times to see what peak surges may be created. One solution may be to parallel that cap with a "Gas Discharge Tube Arrester" , like a Littlefuse AC120LTR, which, will clamp down a DC or AC RMS voltage over 285V, and possibly reduce any arcing peaks causing the contact damage to the relay. That would be a much more "investigative" and time consuming production of a video, so I understand that just replacing the relay as you did and moving on is basically the thing to do, but I am also thankful for you exposing the issue with that particular unit.
@@poormanselectronicsbench2021 You make some interesting points about other types of spark suppression/arrest. While I remember hearing about gas discharge tube arrestors, it never occurred to me for this application. Yeah, at the end of the day the owner got 15 years of service out ot the relays. He's skilled enough to replace them himself, so I advised him to order another set and put them inside the amp's case. At our age, that should cover him for life!
As a general observation, those AC relays look rather underrated for a 1kw amplifier. I would ordinarily expect something like P&B KU series industrial contactors in that situation.
I made an incorrect reply earlier, thinking that the relay Ray was changing was the "output protect" relay, It wasn't. The original relay for the AC power input switching, a OZT-SS-112LM, only has a 5 amp "inductive load" rating @ 120VAC, which is cutting it to its limit if it's switched under full power. I am not sure what the "power on" surge is either, but that could cause a premature failure if it doesn't have some kind of a soft start circuit designed into the unit.
@@poormanselectronicsbench2021 My understanding is that the higher powered ICE modules have soft start in their internal power supplies. But yeah a 5 amp relay in that spot; I'm surprised it lasted as long as it did.
More like which pair of contacts to use is up to you as with Ray cutting of the contacts he didn't want and relays are often used to fire contactors...just sayin :)
@@andymouse The original relays were DPST NO switches Dual Pole Single Throw Normally Open. The replacements were DPDT switches Dual Pole Double Throw. He only needed the normally open side.
Funny story, although it wasn't at the time: I had a Yamaha DSP-1 processor. I used the only amp I had for the rear channels, a Phase Linear 700. I accidentally selected a mode that sent a full volume signal to the rear channels. The woofers on the poor little bookshelf speakers extended out and stayed that way. Lesson learned... you CAN have too much power!
@@raygianelli3612 Indeed ... in fact it's easy to have too much power, these days. Cute story... My "flagship" home theatre system, installed in a friend's basement, is a stack of 3 Crown XLS1002 amps (total 1200 watts) being fed by a home theatre PC (where all the magic happens). The speakers are Fluance Signature series. As we were finishing up the installation and running level checks, my friend's wife was upstairs making supper. I decided to give it one last quick check before eating. So I put on "National Treasure Book Of Secrets". But I neglected to check the volume setting and it started up at full power... Now this is a movie that starts with fireworks, so I makes a mad dive for the keyboard and stopped it about 20 seconds in. That might have been the loudest sound I've ever heard. Then a bunch of yelling and screaming upstairs, someone was full on furious! So my friend and I go upstairs to investigate ... and there's his wife standing over a broken bowl and there is spaghetti literally everywhere in the dining room... I mean everywhere, even hanging from the ceiling! Yep... there actually is such a thing as too much power.
It's unlikely you would draw 15 amps from the wall with this amplifier. 1000w on a 120v service should run around 8 - 9 amps. But when you add in the rest of the system, yeah you might want to have your stereo on a 15a dedicated outlet. Also be realistic ... nobody's gonna listen at 1000w levels... it would be literally painful.
Well, as the owner of this repair, I can’t tell you how appreciative I am. Not only are you knowledgeable on the subject matter, you explain the problem and solution with ease and with a simplicity that is the mark of a pro. Professionals make complexity and hard work appear easy. Never be fooled. If difficult things look easy, it’s because the presenter works harder than most. If you ask anyone that played sports or worked with the worlds best, they all say one thing. They worked harder than anyone I know. Thank you Ray for what you do and for sharing what you do in a way that benefits the world. Thanks so much!
Thanks so much for the kind words, Larry! I've often said the same thing about Ray Dalio. His video "How the Economic Machine Works" takes a complex topic and makes it easily understandable.
That was an easy and economical repair. Bravo for your honesty.
Thanks. All the repairs I do are for myself or friends.
Thanks for posting this, I bought 2 used 1091 mono versions of this amplifier. I really the efficiency and light weight of them. They operate so barely warm. Nice to see an easy fix for this issue 👍
I was grateful that the relays were the only issue since there are no schematics for the power modules.
They are a revolutionary design, and despite what audio purists may say, they're excellent performers.
@@raygianelli3612 Bang and Olufson designed the " ICE POWER MODULES "
Hi good day, GOD bless you for your knowledge
Thank you so much for you kind comment!
Many people generously shared their knowledge with me. Now it's my responsibility to share it with others.
Nice work, Ray. Making the jump over from working on vintage gear to more contemporary stuff has been a bit challenging for me so it's nice to see some of these repairs.
I hear you. I've been watching a lot of Louis Rossmann videos, girding my loins for SMD work. Inevitably I'll have to learn to work with it.
Thanks for the kind words!
Caught that acronym in the beginning. I like it.
😁
Ray is a Telecom tech, and I myself being a retired one, knows that, the life in that work field revolves around acronyms, probably as bad as the military if not worse.
@@poormanselectronicsbench2021 😂 no different than electronics and my other hobby, chemistry. 😂
@@poormanselectronicsbench2021 Truer words were never spoken.
Another super inforative session. Always wanted to know about Class D amp's and their fundamental operation. Nice one Ray......thanks.
Thanks Ian! I realized after I posted the video that I should have mentioned that the ultrasonic products seen on the scope were lower amplitude than they actually are, due to the autoranging on the distortion analyzer.
Class D is actually pretty simple stuff.
The first thing to note is that the "D" does not mean Digital... it was simply the next available letter after A, B, AB, C. At no time is the audio input signal digitized.
The best analogy is to FM radio ... there you are taking an audio signal and encoding it onto a high powered carrier signal. In FM that is done by changing the frequency of the carrier wave, but In Class D it is done by changing the width of square wave pulses (i.e Pulse Width Modulation)
Now in FM receivers you tune into the carrier frequency, then remove the carrier to get the audio back. In Class D you are doing much the same thing... Filter out the PWM carrier and you are left with a greatly amplified copy of the original audio signal.
As Ray pointed out, this gives us a light, small and very powerful amplifier. Modern versions are implemented on chips like the TPA3255 and TDA7498. When properly powered and filtered they will produce hundreds of watts from a box that sits in the palm of your hand, with sound quality to rival many of the "audiophile" world's monster amps.
@@Douglas_Blake_579 Thanks for the detailed reply. Great information.
@@ianmacpherson8385
My pleasure.
That was so gracious of you to share your expertise with the community. Can you post the part number and where we can purchase them. That would be most appreciated. Thank you and God bless you!
Thank you so much for the kind comments!
The original relay numbers are obsolete, but the current one is Omron OZ-SS-112LM1, 200. It appears to be electrically and dimensionally identical. May simply be lead free. In any event, they fit perfectly and worked well. They can be purchased from Mouser or Digikey.
Hi Ray, it's been about five years since I repaired a control board for a friend from his heater and water heater, which had, among other things, a faulty relay for switching the turbo. The original relay is normally available for purchase, but I made a reduction printed circuit board and replaced it with a completely different relay that had a higher load capacity of the contacts when switching the inductive load, if I only replaced the relay with the same type, the fault would repeat itself. So I found another relay of a completely different design with the same current requirement of the coil (so as not to damage the switching transistor), but with a many times greater load on the contacts for switching the inductive load - since the replacement, the defect has not manifested itself. I have no idea if it is the manufacturer's intention that the relay breaks down after a certain period of time and you have to buy a quite expensive control board (authorized repairmen solve this only by replacing the control boards), or it is a bad suggestion from the board manufacturer.
Nice day 🙂 Tom
Hi Tom! I think it was a price constraint mandated by the company's accountants. BTW, nice fix on your friend's heater and water heater!
@@raygianelli3612 Well, I don't think so, the original relay costs more than the one I replaced it with, in my opinion it is an intention to limit the service life, or a mistake in the design of the control board.
@@raygianelli3612 Accountant here!
I promise it comes from the board / those incentivized by profit over mission.
@@justinnitsuj7041 Well, like so many other things in life, you do need checks and balances. Left to their own devices, engineers would design wonderful devices that no one could afford.
Nice repair!…of an evident design flaw. Both amplifier modules have capacitors to be charged, a soft start with a thermistor and relays would have been the right choice for this amplifier, in my opinion. 500+ watts are a lot! Beautiful distortion analyzer and dummy load that can handle it 👍
Those modules are so popular with pro-audio because they are both power supply and amplifier on one board. The higher powered B&O ICEPower modules include soft start on their own power supply boards.
Strongly agree about a soft start! Even with the "spark killer" capacitors across the relay contacts they didn't make 20 years, when much of the vintage gear I see is twice that age and usually still going strong.
Those dummy loads sing under high load, but they're rated at 1,000 watts. Most I've pushed through them is 650.
hey Ray, can you make video about amplifier stages and how to spot them on the circuit without any schematic? thanks, always love watching your video
Annas, depending on the amp that can be tricky. But let me think about it. Maybe I can come up with some general tips for figuring it out.
@@raygianelli3612 thanks Ray, looking forward for your videos
I like the intro and outro
Hi Ray nice repair ! As you upped the power the THD+n didn't look all that good, is this an expensive amp ?....cheers.
Those readings are typical of any high powered amplifier.
Thanks ! :)@@Douglas_Blake_579
@@andymouse
You're welcome. Distortion always rises somewhat right before clipping, then, of course when it does clip the distortion climb is almost vertical. Considering the amp's age (2005) and the state of Class D at that time, it did pretty well.
The rb1092 is an absolute powerhouse amp, but how does it sound ? @@Douglas_Blake_579
@@grogmonster2408
LOUD
As ever, great job done, Ray. I'm in Madrid, Spain, and I'm looking to buy a Levear like yours. It's an execellent piece of gear to have everything toghether, specially THD+PW. Could you tell me or recommend me some place apart from EBay to obtain a good state, second hand unit?. Thanks in advance.
They aren't easy to find outside of Asia. A friend who has a TH-cam channel found his on eBay. There are other measurement systems out there as good or better. Occasionally you can find an Audio Precision unit that won't break the bank. Quant Asylum has an interesting software based system with dedicated hardware that's worth looking at.
At the end of the day you need to evaluate your needs and find a solution that best fits those needs.
@@raygianelli3612thanks a lot for your answer. I thought so: Japanese market. I have a friend there (the one from NFM TH-cam channel). He’s living in Japan. Maybe he can find out something. I send you a big hug from Madrid.
Well done
👍
Ray, did you check the value of C102 & C103? A failure of those could cause the contacts to arc more than they should on power up & down, shortening the relays life. As I mentioned in a reply to douglas_blake_579, I also wonder if this unit wouldn't benefit from some sort of "AC power soft start" addition to take the stress off of the relay when first powering on.
The capacitors measured OK, but who's to say they're not breaking down at higher voltages?
After giving it some thought, I don't think a soft start would help in this case. I believe that the contact arc when they open on amplifier shutdown.
@@raygianelli3612 It would be interesting, but also time consuming , to, do some sort of scope capture of the voltage across the contacts when "powering down" a few times to see what peak surges may be created. One solution may be to parallel that cap with a "Gas Discharge Tube Arrester" , like a Littlefuse AC120LTR, which, will clamp down a DC or AC RMS voltage over 285V, and possibly reduce any arcing peaks causing the contact damage to the relay. That would be a much more "investigative" and time consuming production of a video, so I understand that just replacing the relay as you did and moving on is basically the thing to do, but I am also thankful for you exposing the issue with that particular unit.
@@poormanselectronicsbench2021 You make some interesting points about other types of spark suppression/arrest. While I remember hearing about gas discharge tube arrestors, it never occurred to me for this application.
Yeah, at the end of the day the owner got 15 years of service out ot the relays. He's skilled enough to replace them himself, so I advised him to order another set and put them inside the amp's case. At our age, that should cover him for life!
As a general observation, those AC relays look rather underrated for a 1kw amplifier. I would ordinarily expect something like P&B KU series industrial contactors in that situation.
You're probably right. But in a fight, the bean counters always win!
Agreed, if this was my amplifier, I would probably modify that board to accept a slightly more skookum relay.
I made an incorrect reply earlier, thinking that the relay Ray was changing was the "output protect" relay, It wasn't. The original relay for the AC power input switching, a OZT-SS-112LM, only has a 5 amp "inductive load" rating @ 120VAC, which is cutting it to its limit if it's switched under full power. I am not sure what the "power on" surge is either, but that could cause a premature failure if it doesn't have some kind of a soft start circuit designed into the unit.
@@poormanselectronicsbench2021
My understanding is that the higher powered ICE modules have soft start in their internal power supplies. But yeah a 5 amp relay in that spot; I'm surprised it lasted as long as it did.
i think relays can be either NO or NC in the off state depending on which ones you buy !
Yes they can.
NO == Normally Open, closed when energized.
NC == Normally Closed, open when energized.
More like which pair of contacts to use is up to you as with Ray cutting of the contacts he didn't want and relays are often used to fire contactors...just sayin :)
@@andymouse
The original relays were DPST NO switches
Dual Pole Single Throw Normally Open.
The replacements were DPDT switches
Dual Pole Double Throw.
He only needed the normally open side.
Well, anyone who knows me can confirm I have no idea what normal is! 😁
@@raygianelli3612 that make 2 of us, good vid :)
Fairly easy fix! 500 watts, woofer stretch marks... lol
Funny story, although it wasn't at the time: I had a Yamaha DSP-1 processor. I used the only amp I had for the rear channels, a Phase Linear 700. I accidentally selected a mode that sent a full volume signal to the rear channels. The woofers on the poor little bookshelf speakers extended out and stayed that way. Lesson learned... you CAN have too much power!
@@raygianelli3612
Indeed ... in fact it's easy to have too much power, these days.
Cute story...
My "flagship" home theatre system, installed in a friend's basement, is a stack of 3 Crown XLS1002 amps (total 1200 watts) being fed by a home theatre PC (where all the magic happens). The speakers are Fluance Signature series.
As we were finishing up the installation and running level checks, my friend's wife was upstairs making supper.
I decided to give it one last quick check before eating. So I put on "National Treasure Book Of Secrets". But I neglected to check the volume setting and it started up at full power...
Now this is a movie that starts with fireworks, so I makes a mad dive for the keyboard and stopped it about 20 seconds in. That might have been the loudest sound I've ever heard.
Then a bunch of yelling and screaming upstairs, someone was full on furious! So my friend and I go upstairs to investigate ... and there's his wife standing over a broken bowl and there is spaghetti literally everywhere in the dining room... I mean everywhere, even hanging from the ceiling!
Yep... there actually is such a thing as too much power.
It's 500 watts into 8 ohms. I'd love to see what it does into 4 ohm speakers.
Would a 15 amp circuit be necessary or recommended for owners of this amp ?
It's unlikely you would draw 15 amps from the wall with this amplifier. 1000w on a 120v service should run around 8 - 9 amps. But when you add in the rest of the system, yeah you might want to have your stereo on a 15a dedicated outlet.
Also be realistic ... nobody's gonna listen at 1000w levels... it would be literally painful.
That looks just like the one that I have.
If you do in fact have the RB1092 amp, how does it sound, any good ?
Promo SM 🎊