Class D amp long term reliability

[ahofer]

Age? (not yours, the amps).

NAD c298- 2020, March Audio p252 - 2018

 

[EJ3]

Have you thought of using a heat lamp with infrared bulbs? I use them in a pump room. They only come on when necessary using a sensor to detect the temperature drop.

I had not thought about that yet. Thanks, I'll look into it. Seems like a great idea. I have all summer & part of winter to do something about it.

 

[DVDdoug]

Using incandescent lights for heating seems to be the most inefficient technology.

Ummm... 100% of the electrical energy is normally converted to heat. They aren't as efficient at converting to light. The small percentage of energy that's converted to light gets converted to heat when it's absorbed by a surface. Any light that's not contained and gets-out through openings or windows. Most of that escaping light is absorbed and converted to heat in the atmosphere, but we can consider that lost.... Except for it's contribution to global warming. You'll lose more heat from imperfect insulation than from light.

 

[EJ3]

A simple heater with thermostat should work. It’s not the wattage of the heater that’s important, but whether it’s on for the minimum required time.

There is a level of complexity and cost involved & chances of failure. When you do it when you park the car between the pump house & the main house, you can see that the lights came on through the louvers & that, if they are dim, one needs to be replaced. (Which takes about 2 minutes, at most).
Thermostats, heaters, wiring it for more current, etc.
Since 1964 it only needed to be wired for two 100 watt bulbs.
It requires removing the pump house & building another (if one does it, may as well use new stuff).
And it will need to be made out of something that wont burn, as it is next to the car (one car width away from the house.
And their are new codes to meet because there will be more power used at once.
Nice idea but the implementation is complex & costly, compared to very simple & works very well for a $1000 (at least) less.
Helping the environment by destroying what works simply, inexpensively & replacing it with new, complex systems & materials.
Whoo Hoo! Lets do it!

 

[EJ3]

Thought we had a thread on LED bulbs (or maybe we need one)? Btw @EJ3, recall an initial ban attempt, but plenty of incandescent bulbs still on the market.

They are talking about Europe, where I also have family farm property & relatives in Austria. I was born there.

 

[EJ3]

Have you thought of using a heat lamp with infrared bulbs? I use them in a pump room. They only come on when necessary using a sensor to detect the temperature drop.

In a pair (one for back up). They would cycle on & of separately & unlikely for both go out simultaneously if they are on separate circuits. Some great ideas here.

 

[EJ3]

NAD c298- 2020, March Audio p252 - 2018

Mine are from 1984 , Nothing has ever just failed but one had some stuff go out when a power pole transformer detonated.
Everything was repairable, though.

 

[Roland68]

I have noticed a real difference between domestic LED lights from reputable manufacturers like Philips and Osram, and cheap no name lights. As ever, don't waste your money on cheap junk, and don't blame the type for the bad examples. For me, LED lights have many benefits, and longevity is certainly one of them. Our house has a large central hall with a 20 feet high ceiling, and I am so glad I no longer have to change the bulbs of the ceiling lights. Technological innovation is great. Anyway, here in Europe incandescent lights have been banned for just about all applications, and rightly so, given their far lower energy consumption precisely during the dark hours when our solar panels have no output..

We use various types of LED lighting in our company, and the lighting times can be tracked very well. Neither the LED lights from brand manufacturers such as Osram or Philips, nor from other brand manufacturers, achieved the stated lighting times, often not even 50% of them.
We now also use products that are many times cheaper. Most of them have now achieved lighting times that offer a significantly better price/performance ratio.

 

[ahofer]

Mine are from 1984 , Nothing has ever just failed but one had some stuff go out when a power pole transformer detonated.
Everything was repairable, though.

Before my Class Ds, I had Bryston and Adcom amps of that vintage (more like 1987 and 1990, I think). The Adcom ran too hot and had to be re-capped.

 

[Petrushka]

As long as reliability is being discussed, I’d like to know why inexpensive class D amps are automatically assumed to be less reliable than expensive AB amps.

I can think of only two controllable factors that would affect reliability. One is quality of parts like capacitors that can age. The other is operating components too close to their power rating. I have seen cheap power supplies fail due to surges or brownouts.

 

[rdenney]

As long as reliability is being discussed, I’d like to know why inexpensive class D amps are automatically assumed to be less reliable than expensive AB amps.

I can think of only two controllable factors that would affect reliability. One is quality of parts like capacitors that can age. The other is operating components too close to their power rating. I have seen cheap power supplies fail due to surges or brownouts.

In some cases the issue has been thermal management of the module, at least in the case where power supplies and audio modules have shared the same board.

But my Class D amps work fine while my history has presented several examples of failed AB amps. I suspect it’s much more about design execution than concept.

Rick “anything can fail” Denney

 

[Petrushka]

In some cases the issue has been thermal management of the module, at least in the case where power supplies and audio modules have shared the same board.

But my Class D amps work fine while my history has presented several examples of failed AB amps. I suspect it’s much more about design execution than concept.

Rick “anything can fail” Denney

I have a WIIM Amp, a Sonos amp, and an $80 Aiyima amp. The Aiyima replaced a Fosi amp that failed during a power outage.
None of them get more than lukewarm in normal usage. I do not expect them to last 50 years, or to be repairable. Ten years would be nice.

 

[kelesh]

Sony STR-DA3000ES
One of the first fully digital receivers on the market.
Named S-Master Pro circuit by Sony.
Is from 2003 and therefore 22 years old.
Never been repaired and works perfectly.

View attachment 455899

Funny, I have the exact same DA3000ES, but it is inscribed "DIGITAL DRIVE" above the access door instead of "S-MASTER PRO". Sony buzzwords?

 

[levimax]

I suspect it’s much more about design execution than concept.

Rick “anything can fail” Denney

No doubt. However there is a big change from historical class AB amps which is that pretty much anyone could design and build a class AB amp with a linear PS so there were a huge variety of different designs, some of which failed quickly and some which last for decades, and everything in between. With class D amps, because they are much harder to design and build, there are only a handful of manufacturers making modules that go into every brand of amplifier. If one of these manufacturers makes a mistake it is going to show up in dozens if not hundreds of different brands. With modern design and quality control these generic modules are going to be designed to last for the warranty period but not much longer. This means high end brands don't really have the same control over their quality as they did in the past.

 

[Roland68]

Funny, I have the exact same DA3000ES, but it is inscribed "DIGITAL DRIVE" above the access door instead of "S-MASTER PRO". Sony buzzwords?

No, unfortunately not.
This stems from the Sony confusion of 2002-2003. These are two different devices.
Sony wanted to distinguish two different lines with "DIGITAL DRIVE" (Silver) and "S-MASTER PRO" (Gold), but realized too late the confusion this caused among customers, retailers, discount stores, and distributors.

Sony even released a special "ES Series Receivers
Technical Background" manual at the time, which made the situation even worse.

The STR-DA3000ES "DIGITAL DRIVE" (Silver) and the STR-DA3000ES "S-MASTER PRO" (Gold) are two different devices. The connection panel on the back is also different.

DIGITAL DRIVE technologies
• Clean Data Cycle
• C-PLM
• S-TACT
• Pulse Height Volume
Control

S-MASTER PRO technologies
• Clean Data Cycle
• C-PLM
• S-TACT
• Pulse Height Volume
Control
• DC Phase Linearizer
• Discrete output
transistor
• Toroidal low pass filter
• Two-Stage Pulse Power
Supply

 

[ahofer]

With modern design and quality control these generic modules are going to be designed to last for the warranty period but not much longer.

I'm not sure how we could know this. Perhaps I'm missing something that you think is inherent in "modern design and quality control"

PS - my first class D amp is long out of warranty (purchased 2018) and working fine.

 

[Petrushka]

I'm not sure how we could know this. Perhaps I'm missing something that you think is inherent in "modern design and quality control"

PS - my first class D amp is long out of warranty (purchased 2018) and working fine.

NASA spent a lot of money trying to determine the reliability of solid state devices, and failed. The best you can do is mean time between failure, and for solid state devices operated within specs, it’s a long time.

For example, in thirty years of doing IT for small companies, I only saw one CPU fail, and it was a hot running server CPU. Any device that runs hot will have a shorter life, even if it’s premium quality.

In my personal experience, some devices are susceptible to power brownouts. I lost a cheap Fosi amp and a TV after a brownout. They were both surge protected, and nothing else was affected. If cheap power supplies fail early, it’s probably due to running them at the edge of their rating.

My wife collected old sewing machines, and many premium, Swiss made machines died due to electrolytic capacitor failure. Same as audio equipment and computers. I’m not convinced paying more assures better capacitor life.

 

[dguillor]

No doubt. However there is a big change from historical class AB amps which is that pretty much anyone could design and build a class AB amp with a linear PS so there were a huge variety of different designs, some of which failed quickly and some which last for decades, and everything in between. With class D amps, because they are much harder to design and build, there are only a handful of manufacturers making modules that go into every brand of amplifier. If one of these manufacturers makes a mistake it is going to show up in dozens if not hundreds of different brands. With modern design and quality control these generic modules are going to be designed to last for the warranty period but not much longer. This means high end brands don't really have the same control over their quality as they did in the past.

I think the modules are probably designed to last ant least until the warranty period is over in the worst case conditions and usage. Which means they will last much longer for most people.

 

[kelesh]

No, unfortunately not.
This stems from the Sony confusion of 2002-2003. These are two different devices.
Sony wanted to distinguish two different lines with "DIGITAL DRIVE" (Silver) and "S-MASTER PRO" (Gold), but realized too late the confusion this caused among customers, retailers, discount stores, and distributors.

Sony even released a special "ES Series Receivers
Technical Background" manual at the time, which made the situation even worse.

The STR-DA3000ES "DIGITAL DRIVE" (Silver) and the STR-DA3000ES "S-MASTER PRO" (Gold) are two different devices. The connection panel on the back is also different.

DIGITAL DRIVE technologies
• Clean Data Cycle
• C-PLM
• S-TACT
• Pulse Height Volume
Control

S-MASTER PRO technologies
• Clean Data Cycle
• C-PLM
• S-TACT
• Pulse Height Volume
Control
• DC Phase Linearizer
• Discrete output
transistor
• Toroidal low pass filter
• Two-Stage Pulse Power
Supply

Thank you, very informative. I also now noticed another difference - the first one is "6CH" while the second (mine) is 7CH. I will never actually need any of this, since I only use simple stereo audio, but it is interesting trivia.

 

[pablolie]

There is absolutely no way Class D designs have inherent and universal issues impacting longevity. As mentioned repeatedly, it's down to individual product design and has nothing to do with being "Class D".