Are Affordable Class D Amps the Great Hope for Audio?

[ronniebear]

I concur that affordable Class D hi-fi amps can potentially attract a few new music lovers into the audio hobby. My bottom-of-the-foodchain new acquisition, the new Lepai LP-2020AD (using a Taiwanese ESMT chip), performs surprisingly well. I'm supposed to lend it out for testing, but have procrastinated because it drives my living room Boston Acoustics Sub/Sat system so nicely. Maybe I've gotten a bit infatuated with it, odd as that may seem. If you are going to play a Telarc recording of orchestral music at full concert level or Bach organ works at full throttle --the humble Lepai can start clipping away, but for the majority of listening so far in our 300 sf living room this unit seems to have fairly quiet electronics, no "turn on" thump and a rather minor "turn off" thump. Other than a definite peak output clipping level, the humble Lepai sounds dynamic and produces very appealing audio output. Using The Economist "Big Mac" index, you can buy the Lepai for the price of four Big Macs. Your Lepai or (moving up the food chain) Aiyima A07 Pro may not last for decades like vintage Marantz/Pioneer/Sansui equipment (which does need periodic servicing and repair) but the value proposition is frigging amazing for what's offered. I do look forward to getting some objective measurements of the LP-2020AD, it just seems better than I had imagined.

 

[Deleted member 58421]

Are inexpensive Class D Amps the Raspberry Pis and future, of the audio industry?

As I've alluded to in other threads, I really appreciate @amirm reviewing the low-end (read affordable) Class D amps like the Aiyima A07, using his finite time doing a lot of these reviews rather than some of the really obscure, boutique stuff, though I appreciate those efforts, as well.

Though I, too, salivate at some of the exotic stuff like the new Genelec 8381 (and have decided some time ago that I no longer need to spend crazy money on, say, a shiny McIntosh behemoth or a Benchmark amp when a Purify or Hypex based amp will out perform it for 75% less money), to me, the cutting edge of our hobby are these affordable, entry level products like Aiyima, SMSL, Fosi and even Topping.

More importantly, these entry level amps - and a pair of $300 bookshelf speakers - are a great way to get new folks into the hobby and ultimately keep the lights on at many of our favorite audio companies as they pursue their quest for the Holy Grail of Audio?

When I was a kid in the 70's, virtually all of my buddies were into stereos, car audio etc. Now, not so much. I expect many ASR folks, like me, are on the other side of 50 and when I talk to friends under 35, very few are interested in anything without earbuds or a low fidelity, Bluetooth connected speaker sitting on the kitchen counter. To them, cares about, "THD", whatever that even means...

Though there are many phenomenally cool high-end products on the market today, without gateway products like these Class Ds to fill the front end of the, "audiophile pipeline," is there enough latent demand to keep the industry viable for the next 25 years? That's the question in my mind.

This, in my mind, is analogous to what we've seen in Britain with the Raspberry Pi. I've read that there was a shortage of IT professionals entering the British market in the early 2000s because the kids had switched from playing with computers (BBC Micros, etc.) to video games. Kids no longer knew or cared, about programming. It's my understanding that one of the motivators behind introducing the Pi was to get a $35, fully functional single board computer into the hands of young folks and capture their interest while in their teens and fill the programming pipeline. I'm not British so I don't have first hand knowledge but based on the current backlog of RPs, something must be working.

Could these cheap, Class D amps be accomplishing the same thing by creating tomorrow's audiophiles today?

No I don’t think so, but they could.

Being of a similar age, I think my inclination to hifi was through my dad listening to music on his system. Unless a young person is musical or influenced through a family member or friend when younger I don’t think they’re interested in better quality audio. Well that’s my experience anyway. I’ve talked to numerous people, young and otherwise, and they don’t seem to be interested, I don’t see the cost of the equipment excluding them from the hobby. However, what I do see is that the equipment you’re referring to does allow those interested in the hobby to hear better sounding music at a cheaper price than your standard hifi equipment. In fact this is the route I have chosen for myself now and I can’t see myself going back…

 

[Deleted member 58421]

No I don’t think so, but they could.

Being of a similar age, I think my inclination to hifi was through my dad listening to music on his system. Unless a young person is musical or influenced through a family member or friend when younger I don’t think they’re interested in better quality audio. Well that’s my experience anyway. I’ve talked to numerous people, young and otherwise, and they don’t seem to be interested, I don’t see the cost of the equipment excluding them from the hobby. However, what I do see is that the equipment you’re referring to does allow those interested in the hobby to hear better sounding music at a cheaper price than your standard hifi equipment. In fact this is the route I have chosen for myself now and I can’t see myself going back…

In fact I went to buy an Smsl dac but mistakenly purchased an amplifier (actually the websites fault imo). I was so annoyed when I received it, but when I used it I was so surprised with how good it sounded…I’m selling it now as I’ve gone with Genelec’s but nonetheless it’s a very very good piece of kit.

 

[JCAS]

I think streaming will get bigger and bigger. In and of its self will reduce the hardware purchased. There will always be some people that cherish
owning a rack of electronics and some whopping speakers. The young kids want everything at their fingertips streaming into their earphones.
Lots of equipment just isn't in the mix for them. The industry will be forced to make things smaller and smaller or they won't buy it. The only
thing getting bigger now is TV's but that's getting to the end.

 

[killdozzer]

I guess I could ask here since it says 'audio' and not 'home audio'.

Is there a difference for PA systems and professional equipment? Like putting up a sound system in a Discotheque with Class D amps?

My guess would be there's no difference, but I wanted to get some pro's confirmation.

There has been enough talk about the subject and my guess is that it's just as good. Still, we mainly talk about home audio and yesterday I had a friend showing me measurements graphs for some Class D professional amps he considered for a disco club and it had the same distortion in the upper freq-band like they used to have long time ago.

It got me wondering. Is it, perhaps, still too expensive in this phase and thus maybe not used in professional equipment yet? Did he just choose the bad ones or perhaps set it up poorly? He said he just went for the AB and those graphs were very close to what's been usually praised here as very flat.

 

[fpitas]

I have to think pro amps come down on the side of reliability under heavy use, vs the best FR or distortion. Of course, class D with a switching supply is a back-saver when you haul equipment.

 

[killdozzer]

I have to think pro amps come down on the side of reliability under heavy use, vs the best FR or distortion. Of course, class D with a switching supply is a back-saver when you haul equipment.

Is there an issue with reliability with ClassD?

 

[fpitas]

Is there an issue with reliability with ClassD?

Not if you use good parts and intelligent design. As mentioned in this thread, you have to use capacitors meant for the purpose, and be careful with heat sinking.

 

[Waxx]

Pro amps suffer a lot from the conditions they are used in, even when in a suspended rack. Festivals, concert halls and so are not so friendly enviroments for fragile electronics and the loud music (mainly the bass) beats hard on those amps. So they need to be extra tough build. A toplevel hifi amp would not last long in those conditions. Reliability is way more important than sinad or frequency response for those.

But they are also moving on, the toplevel class D amps of that section of the market of today are way better than those of 20 years ago. Brands like Powersoft, Crown, Lab Gruppen and Full Fat Audio also keep researching and their amps get better. But they are not focussing on low distortion of flat response. They are focussing on high power, reliability and integration in modern digital controlled systems. But it's not that they don't look at Hypex and Purifi and co and learn from them how to do it better...

 

[killdozzer]

Pro amps suffer a lot from the conditions they are used in, even when in a suspended rack. Festivals, concert halls and so are not so friendly enviroments for fragile electronics and the loud music (mainly the bass) beats hard on those amps. So they need to be extra tough build. A toplevel hifi amp would not last long in those conditions. Reliability is way more important than sinad or frequency response for those.

But they are also moving on, the toplevel class D amps of that section of the market of today are way better than those of 20 years ago. Brands like Powersoft, Crown, Lab Gruppen and Full Fat Audio also keep researching and their amps get better. But they are not focussing on low distortion of flat response. They are focussing on high power, reliability and integration in modern digital controlled systems. But it's not that they don't look at Hypex and Purifi and co and learn from them how to do it better...

So it IS possible that pro amps (new models) still don't use the latest tech available and this would make home amps performing much cleaner? He could be right about Class D pro amps, even though there are ones that dealt with the shortcomings?

 

[Waxx]

So it IS possible that pro amps (new models) still don't use the latest tech available and this would make home amps performing much cleaner? He could be right about Class D pro amps, even though there are ones that dealt with the shortcomings?

It's not that they use different or older techniques, it's that the end goal is different than with home audio. Pro audio class D amps are also made largely with discrete components like the higer end hifi amps like Hypex or Purifi (because IC's can't deliver the power needed) and they also use feedback to eliminate distortions, but tuned different for different goals. And Powersoft and the likes are sounding good enough to not matter anymore on the sinad level, even on relative high power. The place where they are searching for improvement is the psu (that often can't deliver the juice for toppower, with sagging as result on max power) and how to integrate them in a bigger digital system with line arrays. It's like comparing heavy trucks with supercars. they use the same tech, but for a different goal.