Class D amp long term reliability

[EJ3]

This is why I prefer separate components, versus integrating them!

Me too.
NAD 4300 Tuner (with a 1/2 wave antenna on the 2cnd story chimney, it seems to compare with CD's.
Sony CDR 500 (NOS)
Three NAD 2200's (late 80's NEW)
Two Apt/Holman Preamps (early 80's)
oppo 205 UHD
Yes, when I send something for work, I miss the unit but I have a backup.

EJ3

 

[AdamG]

I'm really surprised that the Hypex has such a short lifespan, as I have been using some IcePower modules on a few systems for as long as 5 years. My main system has a Class AB Power Amplifier that I bought new two decades ago.

Do you have any supportive or supporting data and/or evidence to substantiate your claims that Hypex Amps have such a short lifespan? Please elaborate on your definition of a short lifespan for similar amplifiers?

 

[DonH56]

My son is still using my ca. 2010 Pioneer AVR that has all class-D amplifiers inside. I think that is the oldest class-D thing in the family. I have AB amps that are pushing 50 that still work, but also a number that failed within a (very) few years. Poor reliability comes in all classes.

The fast switching and such of class D amps makes one question their reliability and certainly one can point to early designs failing fairly quickly. OTOH I remember some early SS designs that had a lot of issues as well, and my decade or so as a TV/stereo repairman does not give me a warm fuzzy about tubes, either. For that matter, my ARC equipment was built like a tank from the look of it, and still had a high failure rate (especially the preamp -- they ran the zener bias string waaay too hot). After an initial learning curve, it seems more about the design for reliability than anything specific to the class of operation.

 

[restorer-john]

Do you have any supportive or supporting data and/or evidence to substantiate your claims that Hypex Amps have such a short lifespan? Please elaborate on your definition of a short lifespan for similar amplifiers?

He may be commenting on the Hypex example I showed in post #54.

It is but one sample and should not be extrapolated to all of their products. However, there are some design issues at hand which do not bode well for true long-term reliability.

 

[antennaguru]

Do you have any supportive or supporting data and/or evidence to substantiate your claims that Hypex Amps have such a short lifespan? Please elaborate on your definition of a short lifespan for similar amplifiers?

Yes, the popular Hypex amplifier module that is the basis of this very thread. The forensic engineering pictures of the failure point(s) show that it was never designed to stand the test of time with its little “heat pad” and bunch of burned up parts SMD parts. These things are all made the same by the module manufacturer. That’s the whole concept behind PA modules!

Now you go and install a bunch of these inside the confines of Active Loudspeakers and you have even more trash to take out, including perfectly good loudspeakers that are rendered trash too because of their dependency on the PA modules.

Over the past 15 years I have had 3 powered subwoofers experience blown plate amps, 2 Class D and 1 Class AB. Name Brand plate amps too, from JBL and ElectroVoice. Not one of the manufacturers could provide a replacement amplifier to purchase for these “older models” so I had to buy generic replacement plate amps on the open market from Parts Express. Not one properly fit the hole left behind by the failed plate amp, resulting in me fabricating sheet metal filler plates - I have a metal shop at my disposal. I also had to drill a bunch of new holes in the wood composite cabinet and cover all of that mess with RTV. Anyone else would just experience planned obsolesence of the whole active loudspeaker - but I was able to fix them, including replacing a woofer that one of the class D plate amps took out as well.

I will not be buying active loudspeakers ever again. Make mine passive and independent of the PA.

 

[kchap]

He may be commenting on the Hypex example I showed in post #54.

It is but one sample and should not be extrapolated to all of their products. However, there are some design issues at hand which do not bode well for true long-term reliability.

Still, you've got me a tad worried. I have Purifi amps with the Hypex SMPS. Fingers crossed.

 

[EJ3]

Yes, the popular Hypex amplifier module that is the basis of this very thread. The forensic engineering pictures of the failure point(s) show that it was never designed to stand the test of time with its little “heat pad” and bunch of burned up parts SMD parts. These things are all made the same by the module manufacturer. That’s the whole concept behind PA modules!

Now you go and install a bunch of these inside the confines of Active Loudspeakers and you have even more trash to take out, including perfectly good loudspeakers that are rendered trash too because of their dependency on the PA modules.

I will not be buying active loudspeakers ever again. Make mine passive and independent of the PA.

It's not just planned obsolesce but it is planned for very short life & more trash in the world. It's a damn good thing that SOME PEOPLE are thinking cradle to cradle (to pass on their stuff to the next generation). Maybe one day the planned obsolesce can be minimized & we can quit generating so much physical waste for no good reason.

 

[restorer-john]

It's not just planned obsolesce but it is planned for very short life & more trash in the world. It's a damn good thing that SOME PEOPLE are thinking cradle to cradle (to pass on their stuff to the next generation). Maybe one day the planned obsolesce can be minimized & we can quit generating so much physical waste for no good reason.

I have no interest in flavour of the month, short operational lifetime products. There's so much more enjoyment to be had from products that perform faultlessly for decades, like a loyal friend. And when they do get old and need a little attention, I fully restore them back to their original (or better) level of performance, ready to give another 40 years of enjoyment.

Just looking at my current system across the room, the components are all 30 years old. The speakers are 20 years old. There's a 45 year old amplifier sitting on a side table, ready to be listened to, after I confirmed it is working in all respects absolutely perfectly. All the components in it are original. Alongside it, is a modern Yamaha AS-300 integrated, a few years old, with remote etc. I would take the 45 year old amp to the desert island if I had to choose between the two- no contest.

The worm is turning and things are changing, slowly. Soon enough, just like kale salad, beards and fixed gear bikes fell off the hipster radar, anyone owning non-repairable, disposable tech will be shamed, cancelled and ostracised by all their friends.

 

[Snarfie]

I have no interest in flavour of the month, short operational lifetime products. There's so much more enjoyment to be had from products that perform faultlessly for decades, like a loyal friend. And when they do get old and need a little attention, I fully restore them back to their original (or better) level of performance, ready to give another 40 years of enjoyment.

Just looking at my current system across the room, the components are all 30 years old. The speakers are 20 years old. There's a 45 year old amplifier sitting on a side table, ready to be listened to, after I confirmed it is working in all respects absolutely perfectly. All the components in it are original. Alongside it, is a modern Yamaha AS-300 integrated, a few years old, with remote etc. I would take the 45 year old amp to the desert island if I had to choose between the two- no contest.

The worm is turning and things are changing, slowly. Soon enough, just like kale salad, beards and fixed gear bikes fell off the hipster radar, anyone owning non-repairable, disposable tech will be shamed, cancelled and ostracised by all their friends.

Besides a restorer looks like your a audio poet to

 

[boXem]

It's not just planned obsolesce but it is planned for very short life & more trash in the world. It's a damn good thing that SOME PEOPLE are thinking cradle to cradle (to pass on their stuff to the next generation). Maybe one day the planned obsolesce can be minimized & we can quit generating so much physical waste for no good reason.

Planned obsolescence is another conspiracy theory that tends to consider engineers as better than what they are.
It is already hard to design HW to not fail before some time while staying in the target costs. Do one really think that R&D budget will be spent to have stuff failing on purpose after a specified duration?

 

[Gorgonzola]

Anecdote FWIW: My ClassDAudio SDS-258 DIY I completed in 2010 is still going strong. Admittedly there were intervals it it was shelved as a backup amp.

This amp has had three different powers supplies, none of which failed but I replaced more for fun than anything else. The longest used was a Connexelectronic linear supply used from 2012 'till it was replaced this year with a Connexelectronic SMPS.

 

[AdamG]

Yes, the popular Hypex amplifier module that is the basis of this very thread. The forensic engineering pictures of the failure point(s) show that it was never designed to stand the test of time with its little “heat pad” and bunch of burned up parts SMD parts. These things are all made the same by the module manufacturer. That’s the whole concept behind PA modules!

Now you go and install a bunch of these inside the confines of Active Loudspeakers and you have even more trash to take out, including perfectly good loudspeakers that are rendered trash too because of their dependency on the PA modules.

Over the past 15 years I have had 3 powered subwoofers experience blown plate amps, 2 Class D and 1 Class AB. Name Brand plate amps too, from JBL and ElectroVoice. Not one of the manufacturers could provide a replacement amplifier to purchase for these “older models” so I had to buy generic replacement plate amps on the open market from Parts Express. Not one properly fit the hole left behind by the failed plate amp, resulting in me fabricating sheet metal filler plates - I have a metal shop at my disposal. I also had to drill a bunch of new holes in the wood composite cabinet and cover all of that mess with RTV. Anyone else would just experience planned obsolesence of the whole active loudspeaker - but I was able to fix them, including replacing a woofer that one of the class D plate amps took out as well.

I will not be buying active loudspeakers ever again. Make mine passive and independent of the PA.

So, No then you can not substantiate your original claims.

One failed unit described in this thread. And several unfortunate personal failures (that may not even be Hypex Amps. As you included, in your 3 previous class D amp failures, a class “AB amp” just for good measure.)

I do understand your bad experience has left a bad taste in your mouth. And you personally have soured on class d plate amps. But I do not think we have sufficient data to support a condemnation of Hypex class-D amps longevity and/or reliability just yet.

Where is the science, data, sample population, failure rate? Have you or anyone else compared existing failure rate data against other existing Amplifier designs failure rates? Again class D amplification is not really new tech. It’s been around what 50+ years. Many major Audio amplification designers and builders are building and selling Class-D amplification products. Let’s leave the hyperbolic statements of fact to all the other Subjective based Web sites.

 

[restorer-john]

Planned obsolescence is another conspiracy theory that tends to consider engineers as better than what they are.
It is already hard to design HW to not fail before some time while staying in the target costs. Do one really think that R&D budget will be spent to have stuff failing on purpose after a specified duration?

With respect, it is not a conspiracy theory. Planned obsolescence is not just a planned failure on a hardware level, it is also the determined position to use proprietary components and not stock, supply, or allow for future replacements, should they be needed.

Yamaha is doing it now and have been for nearly a decade. Dedicated microcontrollers for their top products deliberately unavailable as spare parts.

 

[pma]

Planned obsolescence is another conspiracy theory that tends to consider engineers as better than what they are.
It is already hard to design HW to not fail before some time while staying in the target costs. Do one really think that R&D budget will be spent to have stuff failing on purpose after a specified duration?

You are right, it is definitely not intentional, however the trend to miniaturization, high component density, high power density and temperature and local heat spots, not using the best components because of their price etc. etc. tend to decrease life time and reliability. Let's agree on the fact that it is the consumer electronics that is mostly discussed here and as such it is not designed to survive decades, though some of us, like @restorer-john and me prefer to own or design/build audio systems the would survive and survive 30+ years. Yes, they are not SOTA and on fashion-wave then, however e.g. in case of amplifiers there has been no progress in 30-40 years re sound quality. The things are smaller, however with new issues.

 

[boXem]

With respect, it is not a conspiracy theory. Planned obsolescence is not just a planned failure on a hardware level, it is also the determined position to use proprietary components and not stock, supply, or allow for future replacements, should they be needed.

Yamaha is doing it now and have been for nearly a decade. Dedicated microcontrollers for their top products deliberately unavailable as spare parts.

My problem is the term "planned". There is no grand plan, just that accountants have taken the power everywhere and that anything having a cost with ROI > 3 years is considered as a burden. This drives also the choice for proprietary components and their lack of stocks.

 

[UniPolar]

Thinking back to a time when things were repairable - or at least temporarily fixable - I can recall my parents having to throw away several tube type televisions. Yes, you could get parts and yes, there were shops close by to ' repair ' these, but the reliability ( and performance ) was just not very good over time IMO....

Things did get better with ' solid state' , but as technology advanced there were still 'failure modes' ( CRT tubes that got dim, heat, dust ) and think about just how LARGE amount of waste was created with just a single TV console going into the dump.

Fast forward to today, and as 'performance' has improved, so has reliability to some extent. Also, large scale IC's are compact and generally reliable - though not 'fixable' or repairable ( speaking of the actual IC chip ).

We can rail about conspiracies but personally I would not want to ever go back. There may have been a 'sweet spot ' somewhere in this cycle of 'better', but electronic equipment for the consumer will continue to move forward with perhaps even less 'repairability' by normal homo sapiens..

To improve our situation, we would need to incur extra cost to disrupt the throw away cycle.. And ultimately, folks will likely continue to purchase the less expensive products, even when given a choice.

So, in some sense, we as consumers helped create some of this disposable society with our extremely price conscious shopping habits. Also, there's really no method for a consumer to judge quality or longevity..

 

[dguillor]

I am an electrical engineer who designed class D power circuits for more than a decade. From my experience capacitors are the big worry for long life, and temperature plays a large role their life. Capacitor life can be cut in half by a ten degree centigrade rise in temperature. I think a class D amp could definitely meet your requirements, but I would buy an amp from a reputable company, with a warranty, that had considerably more power than you typically used and that reviews said ran cool.

 

[TheWalkman]

My problem is the term "planned". There is no grand plan, just that accountants have taken the power everywhere and that anything having a cost with ROI > 3 years is considered as a burden. This drives also the choice for proprietary components and their lack of stocks.

Boxem - I think you're spot on: it's not the engineers who are the evil-doers behind planned obsolescence, it's the bean counters, constantly squeezing the pennies out of designs to meet low price points.

This doesn't apply to the boutique, money-is-no-object, "audiophile" systems but for normal, consumer grade electronics, bingo. (Having spent a career in the tech industry, I saw it first hand. The product managers wielded very sharp spreadsheets.)

 

[caught gesture]

There is also Design for Manufacturing. This does not create the best possible product, but the most cost-effective product when it comes to the manufacturing process (and therefore the most profitable).

 

[LTig]

Planned obsolescence is another conspiracy theory that tends to consider engineers as better than what they are.
It is already hard to design HW to not fail before some time while staying in the target costs. Do one really think that R&D budget will be spent to have stuff failing on purpose after a specified duration?

What about light bulbs? As far as I know there was an illegal agreement between the big makers to limit their life span to 1000 hours. Very long ago...