Class D amp long term reliability

[antcollinet]

Agree, but whether Hypex acts is dependent on a identified failure rate or trend.

(Hypex) is not going to take action over one forum post. Will need a few more to take action. For all we know they may have done so. On the other hand, it may not be a major issue or has not hit their radar. We just do not have enough data in my opinion.

Agreed - but not having that data is enough to make me worried were I to purchase an MP module. Problem is it is a potential long term reliability issue. So we don't know if those modules have been in the field for long enough to show a high failure rate. I'd err on the side of my experience and not buy it.

 

[pablolie]

I wouldn't worry too much about longevity - they can all fail at some time, but in practice they seldom do. Otherwise they'd get a very crappy reputation very quickly.

But one thing to keep in mind with integrated amps that incorporate additional functionality and offer -for example- the capability to update firmware, the owner needs to be careful because bricking stuff is easy with such operations. That's pretty universal in electronics though.

 

[RickS]

Agreed - but not having that data is enough to make me worried were I to purchase an MP module. Problem is it is a potential long term reliability issue. So we don't know if those modules have been in the field for long enough to show a high failure rate. I'd err on the side of my experience and not buy it.

I wouldn't worry too much about longevity - they can all fail at some time, but in practice they seldom do. Otherwise they'd get a very crappy reputation very quickly.

But one thing to keep in mind with integrated amps that incorporate additional functionality and offer -for example- the capability to update firmware, the owner needs to be careful because bricking stuff is easy with such operations. That's pretty universal in electronics though.

Thank you both.

Everyone has a level of risk they need to resolve before making a purchase whether it is Hypex or any other vendor.

P.S. Felt I should note that while I respect personal opinions, would need more data to run a quality issue by Hypex.

 

[Marc v E]

@amirm Would it be an idea to have a database on ASR on reliability? I would be very happy to share my experience with various brands.

To keep it simple you could display all info in a graph by brand and type of device (power amp, avr, discplayer, speaker).

One could add type of amp (class AB, D, G) and see what the trends are.

Btw I would expect the failure rates on AVRs and subs to be high because they are relatively complex products that have to deal with a lot of heat and/or mechanicall stress. Disc players and especially streamers should last for years.

Edit: I have had hifi and video equipment serve me well for years, usually more than 1 or 2 decades.

 

[sigbergaudio]

I did a little ad-hoc testing of a Buckeye NC502MP. I ran it continuously at 40 watts and monitored the on-board thermistor. At no time did the temperature exceed 50 degrees or did the module shutdown.

I've done long term testing of temps on our subwoofers, with the Hypex FA501 I don't think I ever saw internal temperatures (three different sensors at different places on the board) above 40C even when driven pretty hard. I also have the impression that Hypex sell A LOT of amps / modules, and I think we would have seen a lot more reported problems if they had a huge issue. They would also likely adjust the design if that were the case.

We're just a small manufacturer obviously and only been using these for a few years, but have had zero failures so far for what it's worth.

 

[Doodski]

I've done long term testing of temps on our subwoofers, with the Hypex FA501 I don't think I ever saw internal temperatures (three different sensors at different places on the board) above 40C even when driven pretty hard. I also have the impression that Hypex sell A LOT of amps / modules, and I think we would have seen a lot more reported problems if they had a huge issue. They would also likely adjust the design if that were the case.

We're just a small manufacturer obviously and only been using these for a few years, but have had zero failures so far for what it's worth.

Class D is ready for prime time!

 

[antcollinet]

Would it be an idea to have a database on ASR on reliability? I would be very happy to share my experience with various brands.

To keep it simple you could display all info in a graph by brand and type of device (power amp, avr, discplayer, speaker).

One could add type of amp (class AB, D, G) and see what the trends are.

Btw I would expect the failure rates on AVRs and subs to be high because they are relatively complex products that have to deal with a lot of heat and/or mechanicall stress. Disc players and especially streamers should last for years.

Edit: I have had hifi and video equipment serve me well for years, usually more than 1 or 2 decades.

Where are you going to get the data from? For certain the manufacturers are not going to supply it.

 

[posvibes]

Anybody know what type of capacitors, resistors, diodes, cabling and wiring etc was used on Voyager 1?

 

[HarmonicTHD]

Anybody know what type of capacitors, resistors, diodes, cabling and wiring etc was used on Voyager 1?

Mundorf for caps to lift the intergalactic veils.

 

[EJ3]

Incandescent bulbs for use in traffic signals came in two power levels; the largest (for the current 12” indication) drew 133 watts. It was rated at 130 volts. Expected life was 8000 hours. The smaller bulbs (for 8” indications) had a life of 10,000 hours.

The LED modules that have replaced the bulb and reflector have an expected life (at 50% reduction in output) of 100,000 hours. And they draw one-tenth the power. They are more expensive to buy, but with lower lifecycle costs. Incandescent bulbs are no longer used by anyone to my knowledge.

Class D has the efficiency advantage going in to reduce lifecycle costs. But I turn my amps off when not in use, so idle draw for me is zero. Heat management is often an implementation issue, however. @restorer-john is there anything you would do to a new Hypex amp to minimize heat issues?

Rick “whose AB amps use unobtanium transistors, by the way” Denney

Today I see many of these LED traffic signal bulbs only partially working. It seems that they don't generate enough heat to survive the mild winters and storms around here (Charleston, SC USA). 3 or 4 two to 4 day freezes a winter. And many storms in the late summer an fall with heavy rains & gale+ winds. Lot's of manpower hours and equipment hours budget killing of the government tax revenue going on because of these vastly over rated, over promoted bulbs. And many failures of them in my own home, although my power bill is lower due to the fact that the LED bulbs make less heat & the A?C runs less. But the money I saved has been spent replacing dead LED bulbs that sometimes don't last a year before being tossed out. H'mm these things also cause much driving around to try to find a brand that might last. And time lost that you cannot get back.

 

[restorer-john]

Today I see many of these LED traffic signal bulbs only partially working. It seems that they don't generate enough heat to survive the mild winters and storms around here (Charleston, SC USA). 3 or 4 two to 4 day freezes a winter. And many storms in the late summer an fall with heavy rains & gale+ winds. Lot's of manpower hours and equipment hours budget killing of the government tax revenue going on because of these vastly over rated, over promoted bulbs. And many failures of them in my own home, although my power bill is lower due to the fact that the LED bulbs make less heat & the A?C runs less. But the money I saved has been spent replacing dead LED bulbs that sometimes don't last a year before being tossed out. H'mm these things also cause much driving around to try to find a brand that might last. And time lost that you cannot get back.

In my experience, it is the opposite. Heat is the problem, but not as you think. The LEDs themselves rarely fail, it is the drivers (compact SMPSs) which fail and primarily that is due to two things.

1. Overheating of the primary filter capacitor after the bridge rectifier, resulting in loss of value, ESR increase and heating/venting/failure. Flashing/dimming etc is a giveaway this is about to happen soon. The supplies are buried in the bulb/fixture and simply cannot dissipate heat as they are sealed.
2. Inability to absorb any powerline related transients or surges.

Pretty much all my home/friends lighting LED failures are caused by those two issues. I've done enough autopsies of the damn things to see a real pattern in the last several years.

The traffic light and LED sign failures I've spoken to some of the guys who do rectification work and it's most often the 'entire' module they replace or blocks of LED signs and mostly its the power supplies in those modules.

The last 3 LED light that failed here, all failed after a simple power interruption. Clearly the transient/over voltage as the local network breakers tripped was just too much for the simple SMPS front end to handle inside the bulbs.

 

[EJ3]

In my experience, it is the opposite. Heat is the problem, but not as you think. The LEDs themselves rarely fail, it is the drivers (compact SMPSs) which fail and primarily that is due to two things.

1. Overheating of the primary filter capacitor after the bridge rectifier, resulting in loss of value, ESR increase and heating/venting/failure. Flashing/dimming etc is a giveaway this is about to happen soon. The supplies are buried in the bulb/fixture and simply cannot dissipate heat as they are sealed.
2. Inability to absorb any powerline related transients or surges.

Pretty much all my home/friends lighting LED failures are caused by those two issues. I've done enough autopsies of the damn things to see a real pattern in the last several years.

The traffic light and LED sign failures I've spoken to some of the guys who do rectification work and it's most often the 'entire' module they replace or blocks of LED signs and mostly its the power supplies in those modules.

The last 3 LED light that failed here, all failed after a simple power interruption. Clearly the transient/over voltage as the local network breakers tripped was just too much for the simple SMPS front end to handle inside the bulbs.

Not having even attempted to find out why they failed, I only have what the guys changing working with the guys who are changing them have said. So as to what is really wrong I do not know But their are a lot of them around here and we do not have much in the way of cold weather, which made me wonder about why they are failing. Thank you for the explanation. As to the home ones, I have noticed that some brands of LED lights do better than others in my home. I also have full time voltage monitoring on my UPS's and they are typically showing 117-120 volts (USA 60Cycle). It will be a few years before I can say that any have outlived my incandescent bulbs, though. But I am down to only 2 of the LED bulbs failing since January of last year, so that is a good sign.

 

[Marc v E]

Where are you going to get the data from? For certain the manufacturers are not going to supply it.

The users on this site could provide the data. It's a matter of trust and number of participans. With about 7000 ASR science oriented members, which have on average 10 years of experience, I believe it has a decent chance.

 

[JSmith]

Would it be an idea to have a database on ASR on reliability?

That could be useful, however I think it would require proper evidence of the failure (date stamped photo) rather than just a comment which could be a potential false post with nefarious intentions.


JSmith

 

[antcollinet]

The users on this site could provide the data. It's a matter of trust and number of participans. With about 7000 ASR science oriented members which have on average 10 years of experience, I believe it has a decent chance.

Insufficient numbers and self selection render that futile.

 

[Marc v E]

Insufficient numbers and self selection render that futile.

Well, as @JSmith suggested, we could require a date stamped photo of the damage. That would adress the self selection and malintent. Likewise for owning a device that hasn't failed. A non stock photo should suffice.

With 7000 members you would have meaningfull data within a few years.

It's comparable to amateur scientists who help discover new stars or asteroids: it is very much possible and helpfull but you got to give it a chance to see what works and what doesn't.

 

[Blumlein 88]

In my experience, it is the opposite. Heat is the problem, but not as you think. The LEDs themselves rarely fail, it is the drivers (compact SMPSs) which fail and primarily that is due to two things.

1. Overheating of the primary filter capacitor after the bridge rectifier, resulting in loss of value, ESR increase and heating/venting/failure. Flashing/dimming etc is a giveaway this is about to happen soon. The supplies are buried in the bulb/fixture and simply cannot dissipate heat as they are sealed.
2. Inability to absorb any powerline related transients or surges.

Pretty much all my home/friends lighting LED failures are caused by those two issues. I've done enough autopsies of the damn things to see a real pattern in the last several years.

The traffic light and LED sign failures I've spoken to some of the guys who do rectification work and it's most often the 'entire' module they replace or blocks of LED signs and mostly its the power supplies in those modules.

The last 3 LED light that failed here, all failed after a simple power interruption. Clearly the transient/over voltage as the local network breakers tripped was just too much for the simple SMPS front end to handle inside the bulbs.

In terms of LED home bulbs, I've been using them quite a while now. With one exception the three failures I have came from power blinks, in one case the power cycled on and off 4 times in less than a minute. I suspect it is over-voltage from spikes that got them. All were under warranty and replaced without issue.

I've done tear downs of a handful belonging to other people. Found the same as you primary filter caps and inadequate heat dissipation. I think nearly all of them were people using LED bulbs in a fully enclosed lighting fixture. I took apart two that had not failed, but had started flashing. Same thing evidence of over-heating.

Nonetheless they seem to last more hours than old bulbs on average. You gain in reduced electrical cost and the LEDs are not expensive anymore for the basic bulbs.

 

[Blumlein 88]

Insufficient numbers and self selection render that futile.

Yeah, maybe so. All I can say is my class D amp is 12 years old and no issues yet. Have a 20 year old class D amp that ran my Soundlabs for 10 years which I keep in a spare bedroom system and they still work. Probably not so many hours since becoming a backup amp.

I did have an AVR failure on a unit that was 16 years old. It was not class D.

 

[Blumlein 88]

Anybody know what type of capacitors, resistors, diodes, cabling and wiring etc was used on Voyager 1?

The Brains of the Voyager Spacecraft: Command, Data, and Attitude Control Computers - News

Learn about the computers at the heart of the Voyager spacecraft operations.

www.allaboutcircuits.com

This article is not about Voyager, but goes into how space electronics are made differently.

Space grade electronics: How NASA’s Juno survives near Jupiter

Take a look at how electronics of spacecraft are built to survive the harshness of space environments.

www.planetary.org

 

[antcollinet]

Well, as @JSmith suggested, we could require a date stamped photo of the damage. That would adress the self selection and malintent. Likewise for owning a device that hasn't failed. A non stock photo should suffice.

With 7000 members you would have meaningfull data within a few years.

It's comparable to amateur scientists who help discover new stars or asteroids: it is very much possible and helpfull but you got to give it a chance to see what works and what doesn't.

How does that solve the problem of people naturally being more likely to report a problem than report not having a problem? Look at the topping PA5 thread. There are enough failure reports to indicate there is an issue, but we still have no idea what the failure rate is since anyone with a problem will goolgle for it, find that thread, and post their issue. Even then we are only able to detect a serious problem. If the failure rate was a more typical <2% we'd not have any data on it, other than one or two disgruntled members which could easily be a random distribution variation.

With 7000 people you'd have no meaningful data ever. Product sales life is generally only a few years at the volume end of the market. People are generally not changing their kit every few years, and we are a tiny part of the market. Even if they do change their kit regularly then you get no data on long term reliability.

You can't get any information on reliability without data only the manufacturer has - how many units have been sold - how many have been returned failed.