How do you feel about the proliferation of Class D in high end products?

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Mike B.

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I am seeing more and more very expensive amps and integrated amps with Class D based output stages. The approach seems to be a bigger/better power supply, and a front end of their own design compared to mid fi offering. I might be oversimplifying things by believing this approach is a less demanding design and consruction process.
What is your take on this?
 
Class 'D' is a rapidly developing technology, with everything from hearing aids to TV sets using Class 'D'. But a high quality Class 'D' audio amplifier still takes a highly skilled design engineer. But yes parts costs should be lower and construction process be less demanding.
 
If the amp sounds good then it sounds good

I could care less what operating class it is....
 
If they can make them sound great, I’m all for it. As long as it’s not to the exclusion of other topologies.
 
I use multiple Ncores per side and am quite pleased. Sometimes, however, I do feel like I'm in a class (d) all by myself :-)
 
Kingsrule said:
If the amp sounds good then it sounds good
I could care less what operating class it is....
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Well then, you're obviously not a true subjectivist. One who has to know a mountain of objective metrics like current, op amp, power supply, price, weight, copper purity, sample rates, what grade aluminum, etc, etc, etc.
To then declare, "Its all subjective".

cheers,

AJ
 
I'm perfectly happy with my ATI AT542NC Class D amp in the main system, and just signed up for more in my new theater installation. As for the comment about commanding top tier prices, who cares if they don't? If I can power my system for $3k or $6k instead of $10k+, and it doesn't have any sonic issues to my ears, I'm perfectly happy to pocket the difference. Otherwise it's just spending more so you can say you spent more. And frankly, the top tier Class D amps now objectively measure just as good as, if not better than, the top tier Class A and A/B amps. Maybe some issues with ultra HF switching frequency, but I haven't heard it in the output. And the newest GaN topologies may well put that item to bed too. The Purifi modules and the NC500 and NC1200 modules are definitely worth a listen. Double blind if you can, just to eliminate the expectation bias that might come with a Class D unit in the loop...
 
Personally, if I could get a Class D amp with as much power and that sounded as good as my Pass then I would buy it in a heartbeat. The heat created by the Pass amps in the summer is more than I can handle. However, I love Pass in the winter. :)
 
Mike B. said:
I am seeing more and more very expensive amps and integrated amps with Class D based output stages. The approach seems to be a bigger/better power supply, and a front end of their own design compared to mid fi offering. I might be oversimplifying things by believing this approach is a less demanding design and consruction process.
What is your take on this?
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There will always be manufacturers that want to sell to the very well heeled who demand very costly cases, socketry, power supply etc to justify this high cost. Nothing wrong with that - it happens with all Classes of ss and tube amp. These brands are likely to have incorporated the base Class D module with their own mods to suit their "house sound" or to best match their other products.

Other brands that expect huge sales volumes can do the same at much lower cost because their R&D cost can be spread over thousands rather than dozens of units. Some of us turn up our noses as these "common" brands, but their amps may well be just as good sounding, reliable and well built as the "cottage industry" very costly ones.

What gives Class D a bad reputation are the "cheap" offerings that bung a standard module into a box with minimal quality of other parts of the amp - the sort of thing you'll find offered for a few hundred bucks on Ebay. A GOOD Class D is now as good as any technology and manufacturers can tweak the sound to mimic for example SETs probably better than they could using Class A or A/B circuits.

Overall Class D has the advantage of demanding MUCH LESS power from the AC supply so its power supply doesn't need to be anywhere near as BIG - although it needs to be just as GOOD. This significantly reduces build cost and the smaller space needed and lack of cooling devices, etc can reduce case size and therefore more cost saving. And the owner will reduce his electricity bill over many years so can afford to buy a more costly Class D than Class A or SET for the same long-time cost!

I like My NAD Master Series! Sounds great - sensible price!
 
many years ago on a hi fi forum i used class D amps , some used to chide me and get some proper amps . so another 10 years later of class A , class AB etc we are back to class D here . sounds pretty fine to me and a lot smaller and more convenient than many amps . both are icepower and rather good i might add
 
BlueFox said:
Personally, if I could get a Class D amp with as much power and that sounded as good as my Pass then I would buy it in a heartbeat. The heat created by the Pass amps in the summer is more than I can handle. However, I love Pass in the winter. :)
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Pass amplifiers are engineered to have a very euphonic sound.
For Class 'D' amplifiers, the goal is an accurate sound.
There is no reasonable way for a Class 'D' amplifier to have a Pass like euphonic sound.
 
I owned a pair of Channel Islands D200 amps about 6-8 years back. I had them for summer use. They operated flawlessly and were revealing with powerful bass performance. I think they were based on older Hypex modules? After some time I realized I was listening much less to them. I never got emotionally involved. That probably says more about me and my tastes than about the amps.
 
Mike B. said:
I owned a pair of Channel Islands D200 amps about 6-8 years back. I had them for summer use. They operated flawlessly and were revealing with powerful bass performance. I think they were based on older Hypex modules? After some time I realized I was listening much less to them. I never got emotionally involved. That probably says more about me and my tastes than about the amps.
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Class D has improved massively over those 6-8 years. I had a Red Wine Signature 30-2, a dreadful Tripath amp compared with modern Class D such as DirectDigital, Purifi and others.

Pass Labs and other Class A amps require a nuclear power station to keep them going and (in this day and age) really is a bit of an irresponsible purchase, specially if left running 24/7 if one has any consideration for the environment.
 
My Class A Accuphase amp draws 158 watts at idle or at full power. I wouldn’t call that irresponsible. My electricity costs $.10 per kW, so even if I left it running 24 hours/day the daily cost is under $0.38.
 
Oly said:
My Class A Accuphase amp draws 158 watts at idle or at full power. I wouldn’t call that irresponsible. My electricity costs $.10 per kW, so even if I left it running 24 hours/day the daily cost is under $0.38.
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My Accuphas A36 Class A (the smallest they make) uses 155 watts at idle, but 270 "in accordance with IEC 60065" whatever that is, but I suspect a much more realistic wattage.

The Accuphase is relatively efficient for Class A but it still gets hot. Many Class A owners complain at the heat output in summer (adding to AC requirements) but welcome in winter! EU versions require that they switch into standby (not just idle) after a period of no signal input - a legal EU requirement for environmental reasons.
 
158 watts is what I measure using my inline watt meter not from something printed on a spec sheet.
 
Class D amps still have that negative general perception as to the SQ but slowly the perception is eroding because of new ClassD amps emerging on the bloc. From my point of view I have heard the ATC SCM40 with the ATC SIA2-100 amp (& Dac) at the Bristol HiFi show and was smitten. But I do not have the finance to stretch to an amp costing £2,500.00. So I looked at Nord amps (ClassD) and there is a versatile Dac, namely the Nord One SE INT-C N 252MP Integrated Amp (Class D) 200wts x 8ohms, price £699 and German RME AD1-2 FS Dac & headphone amp price £729. Together I have Amp & Dac for £1,428 that is £1072 less than the ATC amp & Dac, also this Nord amp can give 200wts at 8ohms instead of just 100 wts at 8ohms of the ATC amp which in theory should exploit more deeply the talents of the speakers. Reviews of Nord amps seem positive even sometimes gushing as to SQ, so such as above is the attraction of Class D amp for me. However the hidden snag for me is one buys direct from Nord the amp & dac without any audition, and the 14day return if not satisfied offer from Nord is not really an assurance but more of an hasstle and headache for me, so there is a big element of risk for me. I wish Nord sold amps like AVI use to sell speaker systemsin that they have a thread in forum where users offer to have their amps auditioned in their homes for aspiring new owners. Decisions, decisions!
 
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