Class D amp long term reliability

[Trell]

This discussion is the exact reason I love the beauty and simplicity of the logarithmic scale.
If the overall power consumption difference between ClassAB/ClassD is but <2dB: Yet, the potential for audio signal mayhem by ClassD are orders of magnitude higher; I think I will continue to re-use our live Christmas tree every year and feel only <2dB guilt about buying ClassAB amps in the future.

You are missing the point of the power consumption discussion above as it's about actually used power, and here using a logarithmic scale is not appropriate.

 

[DonH56]

2 dB = 1.585x

I would be unhappy if my electric bill went up 58.5%.

I am also wondering the supporting data for "the potential for audio signal mayhem by ClassD are orders of magnitude higher"?

 

[pjug]

You are missing the point of the power consumption discussion above as it's about actually used power, and here using a logarithmic scale is not appropriate.

I thought the log scale comment was meant as a joke. A way to hide the reality of the situation from yourself. Kind of like me telling you I am 39 years old, in hexadecimal.

 

[antcollinet]

I thought the log scale comment was meant as a joke. A way to hide the reality of the situation from yourself. Kind of like me telling you I am 39 years old, in hexadecimal.

Ha! That makes me 0.3dB older (Or 0.15dB if we associate age with power rather than volts)

 

[pseudoid]

I knew I should have used 'dog-years' for my corollary for the common folk.
Why stop at <2dB? I guess the best solution would be to go totally green and full stop listening audio using electricity [NOT]!
In the interim, it is NOT like ClassD is the only alternative to my ClassA/B preference. Emotiva's (I think it is a near-ClassH - followed by ClassA/B for analog sections) design gives me hope, yet not fully matured.

 

[audio2design]

I currently own a 2000 Nissan Frontier, a 2007 Honda & a 2012 Lexus These vehicles are not out in the elements when they are at home. The 2000 Nissan & the 2007 Honda will likely make 200K. The Lexus currently only has 31K on it & has several computer failures (not fatal to the car yet) but will soon cause it to need a new main computer. At this time, I can still get one. But, based on this ones history (and going by time), I will need another computer for it in 9 years (or less), when the car will likely have 130K on it & the computer will be made of unobtanium at any price. I do not foresee the Lexus making 200K. In addition to that, the annual expense of the maintenance (even though there was less of it) for these three vehicles has been much more than my former USA & German cars. The Lexus is what tipped that away from being about the same as the former vehicles. Hopefully the next vehicle we buy will be a USA or German brand again.

Lexus is a premium brand with premium costs. German brands with the exception of luxury brands, and even then only recently are not known statistically for their reliability. However NA and Europe brands all became much more reliable due to Japanese reliability pressure. They changed consumer expectations.

 

[Koeitje]

In all of my stereo equipment that uses Class AB (2 receivers, 1 integrated amp, 2 preamps and 7 amplifiers). from 1973-Today I have had precisely 1 failure of one amplifier channel and that failure could not be attributed to the amplifier itself but to a home electrical system power surge from an outside source. I still own and use all of the stereo items that I mentioned.

I owned 2 class AB amplifiers, one I bought brand new and had problems after 3 years. This was a €400 amplifier, so not very high-end or anything but from a reputable brand. The second one I bought second hand and that one lasted a bit longer, but at around 15 years it had several issues. It was also a lot more expensive (Converted about €2000 MSRP excl. inflation), but still plenty of issues. My current NC400's I bought second hand and they are about 8 years old by now I think, the guy I bought them from said he bought them not too long after they released. Zero issues.

 

[EJ3]

Lexus is a premium brand with premium costs. German brands with the exception of luxury brands, and even then only recently are not known statistically for their reliability. However NA and Europe brands all became much more reliable due to Japanese reliability pressure. They changed consumer expectations.

My German cars have been a series of air cooled VW Beetles (64, 67, 69, & three 71's all exceeding their original HP & Torque out put ratings by 30 to more than 100% [the 71 Super Beetle was the only one bought new, made the most power {105 HP} & got the best economy) & all made the 200K mark. As did my 1981 Mercedes 300D, 2004 Mercedes E320. American cars: 1968 SS396 Chevelle (low performance 325 HP [more like 375]), 1972 Ford Mustang Grande (351 Cleveland [least expected to go well over 200K did well over 300K], a 78 & a 79 Pontiac Trans/Am (both automatics) & a 79 4 speed manual Trans Am, 1982 Chevrolet Caprice (with a 2004R trans build at 50K, switched to a 700R4 at 80K) & all of the aforementioned did over 200K. Italian cars 71 Alfa Romeo Spyder, 68 Fiat 850 (neither made 150K). Japanese cars 2007 Honda Fit (bought new, sold due to leaving Guam) but still going with 60K on it), 2012 Lexus ES350 (bought new, which is the one with the computer problems, currently at 31K) and a currently owned 2000 Nissan Frontier 2.4 liter (right now 188K, nursing it along, it will need about 3 grand of work to keep going after 200K (body/trans/chassis ok, engine needs head gasket, valve refreshment, timing chain & tensioner kit with the sprockets and heater core) big expense but likely worth it.
The outliers for most overall expense are the Italian stuff, the Lexus & the Nissan Frontier (to be fair, a truck that gets used heavily as a truck).

 

[antennaguru]

I owned 2 class AB amplifiers, one I bought brand new and had problems after 3 years. This was a €400 amplifier, so not very high-end or anything but from a reputable brand. The second one I bought second hand and that one lasted a bit longer, but at around 15 years it had several issues. It was also a lot more expensive (Converted about €2000 MSRP excl. inflation), but still plenty of issues. My current NC400's I bought second hand and they are about 8 years old by now I think, the guy I bought them from said he bought them not too long after they released. Zero issues.

I have a Hafler DH-220 Class AB amplifier (kit version) I built on my kitchen table back in 1984 when I lived in an apartment, and it was then my main amplifier for well over a decade, when I then started loaning it out to other people whose amplifiers I was repairing, so they could still listen to music while I repaired their amplifier, and today that DH-220 (kit) still works perfectly after 37 years of continuous operation - including driving some crazy loads over the years including electrostatics. The only thing wrong with it was that one of my customers used it in a damp basement and the chassis got a little surface rust on it, so I sanded that off and re-painted it with Krylon spray paint. I have fixed nothing inside for 37 years and it still plays music fine. I have a bunch of other Class AB amplifiers that work fine at 20+ years of age. In fact, my main reference system has an Ayre Class AB amplifier that is 25 years old that I bought new and still beats the living $hiiiit out of other amps I have had here including an NAD C298 (Purifi modules inside) sound-wise, and it still performs and sounds fantastic today. I have done numerous swap comparisons and it just wasn't fair to the other amps. We all laughed that people actually like the NAD C298 - what a horrible sounding POS!

 

[Larry B. Larabee]

Have any Japanese receivers failed in the last 40 yrs. I don't think so.

 

[Trell]

Have any Japanese receivers failed in the last 40 yrs. I don't think so.

Of course there are those that have failed and claiming otherwise is just

 

[Larry B. Larabee]

Of course there are those that have failed and claiming otherwise is just

Few and far between. The only one familiar is the Onkyo HDMI debacle.

 

[Trell]

Few and far between. The only one familiar is the Onkyo HDMI debacle.

That is not what you claimed in your post that I replied to. You are moving the goal post.

All manufacturers have devices that fails prematurely for various reasons, but some more than others.

Customer support when this happens, and it will, is what separates the good from the bad. An example not to follow is Starke that had an amplifier reviewed this autumn, dragging down even the reputation of Audioholics.

 

[wwenze]

My Yulong TA2024 is 15 years old already, wow.

 

[jhaider]

To add a single data point to the discussion of Class D amp reliability, we've used a Hypex UcD180-based amplifier (Pro-Ject Amp Box SE) in various secondary systems for 16 years or so. This amp crams two UcD180 modules and a 12V trigger circuit into a small box (Pro-Ject's standard double-height enclosure) but has the PS on a wall wart. It has yet to skip a beat.

 

[EJ3]

To add a single data point to the discussion of Class D amp reliability, we've used a Hypex UcD180-based amplifier (Pro-Ject Amp Box SE) in various secondary systems for 16 years or so. This amp crams two UcD180 modules and a 12V trigger circuit into a small box (Pro-Ject's standard double-height enclosure) but has the PS on a wall wart. It has yet to skip a beat.

This is something that I like to hear. So it is possible that somehow a CLASS D implementation will work long term. Even though it does not seem to be the norm, it raises the hope that there are some who have reliability of more than a few years (inadvertently or not). Based on what I have seen & heard, other CLASS D manufacturers would do themselves a favor if they would find out why some implementations are much more reliable than others (and implement those protocols, whatever they are. Because, for me (and I suspect many others) I am not even going to look at what the other factors are if it doesn't have reliability.

 

[DonH56]

Have any Japanese receivers failed in the last 40 yrs. I don't think so.

I used to be a tech and plenty of Denon, Kenwood, Marantz, Nakamichi, Pioneer, Sansui, Sony, etc. products needed servicing. And a skim of various audio fora today will highlight issues with them today as well. Maybe they have a lower failure rate but it certainly ain't zero.

 

[pseudoid]

Have any Japanese receivers failed in the last 40 yrs. I don't think so.

...but you'll have second thoughts about going dumpster-diving for any old Japanese audio hw that people throw out.

 

[SIY]

I have a Hafler DH-220 Class AB amplifier (kit version) I built on my kitchen table back in 1984 when I lived in an apartment, and it was then my main amplifier for well over a decade, when I then started loaning it out to other people whose amplifiers I was repairing, so they could still listen to music while I repaired their amplifier, and today that DH-220 (kit) still works perfectly after 37 years of continuous operation - including driving some crazy loads over the years including electrostatics. The only thing wrong with it was that one of my customers used it in a damp basement and the chassis got a little surface rust on it, so I sanded that off and re-painted it with Krylon spray paint. I have fixed nothing inside for 37 years and it still plays music fine. I have a bunch of other Class AB amplifiers that work fine at 20+ years of age. In fact, my main reference system has an Ayre Class AB amplifier that is 25 years old that I bought new and still beats the living $hiiiit out of other amps I have had here including an NAD C298 (Purifi modules inside) sound-wise, and it still performs and sounds fantastic today. I have done numerous swap comparisons and it just wasn't fair to the other amps. We all laughed that people actually like the NAD C298 - what a horrible sounding POS!

Cool story, bro.

 

[BoredErica]

Have any Japanese receivers failed in the last 40 yrs. I don't think so.

Few and far between. The only one familiar is the Onkyo HDMI debacle.

You've been defeated by your own post. Congrats.