Reliability of cheap class D amplifiers

[tomtoo]

If we talk about tpa 3255 this chip is well protected.

 

[alfarn]

Please try not to use that term;

Let's Avoid the Term Chi-Fi

I often see the use of the term "Chi Fi" to describe audio products from China. I see the intention and don't think anyone is trying to be racist and what have you. Still, I like us to show the highest respect to products from around the world. As avid readers of this forum know...

www.audiosciencereview.com

JSmith

Good point, noted. My intentions were not to use the term in a derogatory manner, but being new to this topic I was parroting terms I had seen used in similar discussions. I'll avoid it in the future. Unfortunately I can't edit my previous posts anymore.

 

[JSmith]

Good point, noted. My intentions were not to use the term in a derogatory manner, but being new to this topic I was parroting terms I had seen significantly used in similar discussions.

No worries mate, wasn't having a go at you, just pointing it out. We do try and respect all countries here, being an international forum.

Your reply post is most appreciated.

Is there any amplifier that has proven to be more reliable than the rest or do I just have to accept the risk if I buy a cheap class D mini amp?

Cheap is just that... cheap. That said, people tend to comment more if they have had a problem with product than those with positive experiences. I like to balance price with build quality, functionality, aesthetics and measured performance. TI chip amps will be cheap and perform ok for most situations, but may not be as robust for longevity. I think the Ncore and Purify based module amps are better for both performance and reasonable longevity as long as they're not just stuck in a case without any thought in relation to cooling/heatsinks.


JSmith

 

[Palladium]

I use cheapo PC motherboards all the time that have far more complexity than amps and never had one fail, probably because I ran them with PSUs that are decent at least.

 

[Cawafuoshi]

Long time reader, first time poster. I know, I am a bit late to respond, but just for the record: my Fosi BT30D has been going strong without problems for more than 16 months now.

Given, I never used the BT, and the sub needs a bit of a waking up procedure by turning up the volume on the Fosi before dialing it back to my preferred setting, but otherwise I am in love with it.

Of course, I recently have considered something more stylish from the other common brands, but whenever I reconsidered my needs, the Fosi always wins as long as it keeps working.

 

[Alice of Old Vincennes]

Over the past fifteen or twenty years, I’ve owned probably a dozen Class Ds (Tripath, Lepai, multiple Aiyimas - A04s, A07s, Pros, etc., Topping,, Audiophonics, etc.) I’ve never had a single problem with a Class D.

i think a few people who have had problems (like the apparent bad batch of Topping amps) have been very vocal and are giving them all a bad reputation.

Buy a $75 Aiyima AO7, plug it in and enjoy it.

Buy a Crown for reliability. Can also use for self defense to bop a burglar on head.

 

[TheWalkman]

Buy a Crown for reliability. Can also use for self defense to bop a burglar on head.

I actually purchased an Audiophonics Purifi (Class D) last July and it appears to be my end game amp.

(I’m not wasting that jewel on a burglar: I have a double barrel, twelve gauge shotgun that is far better suited for teaching a burglar a painful lesson.)

 

[Angsty]

If anything it feels like the capacitors of computer speakers using class AB amps tend to die faster, and the heat isn't helping.

I have two, beefy 20+ year-old Class AB amps that are likely to last another 20 years. With preventative recaps two years ago, they may be the last power amps I ever buy. However, they are certainly not “computer speaker” amps.

I don’t think Class D amps are inherently less reliable than Class AB (for similar price). I can say I have Class AB amps that have lasted decades, as they were designed for longevity and repairability. Where is the repair manual for those computer speakers, eh?

There are lots of “receivers” in the audio graveyard with Class AB amps for the same reason that there will be Class D amps there; the cost of repair well exceeds the cost of replacement.

The complexity of Class D is what gives me pause about the longevity; the designs may be too difficult to repair when component aging happens. In a more modern design, I’d prefer what Benchmark is doing: Class AB amp with a replaceable switching power supply.

 

[woodpigeon]

I’ve been a reader here for a while researching a desktop system and now just need to pipe up.

So far in my quest for compact desktop audio I’ve (briefly) owned:
- 2x Topping PA5
- 1x Topping MX5
- 1x NAD D 3020 v2

Both PA5s failed within a few weeks. The MX5 was dead out of the box. The NAD is either faulty or just terrible — can barely drive desktop speakers.

Tonight I’ve just given up and resigned myself to having a bulky amplifier on my desk. Plugged in a 20-30 year old second hand Yamaha AX-497. It works flawlessly and sounds much better than any of the cheap class D options I’ve tried so far.

Lesson learned.

 

[TonyJZX]

i sympathise with you however you've basically bought three Range Rovers and come to the conclusion that all SUVs are unreliable.

I have no love for Topping at all, so that's that... and as much as I'm ok with NAD they arent known for reliability.

I think other Chinese units have decent reliability... the A07 everyone seems to have and the SMSL ones seem to be ok too.

 

[woodpigeon]

Right so in your mind Topping and NAD are the issue more so than the amplifier topology or price point. Interesting. I could give Aiyama or SMSL a go but I’ve had enough of spending my lunch breaks at the post office for a while…

 

[Angsty]

It's less about circuit topology (Class D vs. Class AB) than it is about design for longevity and repairability. Audio Research released the DS225 and DS450 amps back in 2010 - 2011 and they represent the "long-lived" approach to Class D. That approach is expensive.

In counterpoint, Hypex and Purifi modules are made in volume to a specific price point, without an explicit notion of repairability. The repair intent likely would be to replace the entire module in a failure versus fixing specific faulty components.

Topping devices don't scream longevity-designed to me, even as I own one. It works perfectly well, until it doesn't.

 

[Ricardus]

I’ve been a reader here for a while researching a desktop system and now just need to pipe up.

So far in my quest for compact desktop audio I’ve (briefly) owned:
- 2x Topping PA5
- 1x Topping MX5
- 1x NAD D 3020 v2

Both PA5s failed within a few weeks. The MX5 was dead out of the box. The NAD is either faulty or just terrible — can barely drive desktop speakers.

Tonight I’ve just given up and resigned myself to having a bulky amplifier on my desk. Plugged in a 20-30 year old second hand Yamaha AX-497. It works flawlessly and sounds much better than any of the cheap class D options I’ve tried so far.

Lesson learned.

Cheesum crimers. That's statistically unlikely, so I'd say it's time to play the lottery and see if you win!

 

[wwenze]

Told u the main problem is the shipping.

 

[CleanSound]

I have the SMSL DA-9. The issue I keep having is that it would freeze up during power on. I would need to unplug it to fix the issue.

I am on my 3rd placement unit. And the issue just happened again and looking at my 4th replacement.

If I have to do it all over again, I will likely not buy it.

 

[grogi.giant]

I have the SMSL DA-9. The issue I keep having is that it would freeze up during power on. I would need to unplug it to fix the issue.

I am on my 3rd placement unit. And the issue just happened again and looking at my 4th replacement.

If I have to do it all over again, I will likely not buy it.

This is the biggest issue with the electronics these days... As soon as the replacement is out, the software is not being fixed up.

While I understand the desire to push new products every year, otherwise they seem old. However, what the companies could do is keep the internals the same and only update the visuals... That way they could keep releasing software updates much longer.

With the DA-9... The AO200 was released and it seems SMSL doesn't care about DA-9 anymore...

 

[woodpigeon]

To be fair to class D, I think the question is mainly around reliability of “cheap” amplifiers in general… the Schiit Gjallarhorn (latest amplifier in an ongoing saga) is a very nice sounding unit but the transformer in it buzzes like a fridge. Schiit support’s advice is basically “yeah they do buzz a bit, nothing to be done”. Back it goes.