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Design of the power supply is critical to the design of any amplifier of any class. If you mean linear versus switch-mode supplies, there can be good and bad implementations of each.So you want to reduce the output of the Ncores, which make 400 watts into 4 ohms, by using a differently power supply? Unless you are up for experimenting and really know what you are doing, I don't think I'd fuss with different PS implementations. That said, you almost certainly could run the amps with lower voltages -- and I think I recall the designer discussing that issue somewhere in the DIYaudio thread. In my view, though, I don't think it makes a lot of sense unless you're up for an adventure.
Absolutely agree, the rest of the equipment's no good if the power supply isn't up to snuff. My comment was more directed toward the SMPS that are being used with the class D amps in general; there have been a few comments about the switching power supplies introducing artifacts noticeable if the power supply isn't designed well. I haven't settled on a brand yet, just testing the waters right now. From perusing diyaudio.com, I'd seen the threads about the predecessor to the Ncore (UcD?). Now the Ncore stuff is blowing up here. The ClassD audio offerings have caught my eye as well. Nice to find that there are also other vendors that offer kits on Ebay and other sites. Far as up for an adventure, not sure at this point. The first amp I built was an F5 clone, wading through the threads on diyaudio about the various output devices, configurations, etc etc I'm looking forward to something with pre populated boards and onboard Molex connectors.
That easily can go with switching amp supportes as well...your post is not logical...nor accurateThey simply prefer music from an amp that is NOT switching states thousands of times a second...having to filter out all kinds of non acoustic artifacts from the signal.
As an example, a class A amp from Pass Labs does a much cleaner job of reproducing in incoming music signal than any switching amp. No data on HOW the Ncore switching amp has overcome it operational limitaions has yet been posted.
I must admit that I have a grudging admiration for those who only use their turntables and tape machines for musical reproduction, eschewing those horrible switching artifacts spilling from CD players and DACs.My youngest son used to march about demanding of all 'Proob It!!' But he is no longer 4 years old, and does his own research. If you'd do a search either here or on Google on 'Ncore white paper' you'd have found it. [it IS the Ncore that is the proximate cause of this cat fight] For a white paper, it seems short on hyperbole, and actually contains useful information. You could also read Bruno Putzey's AES papers. Actually, given your demonstrated technical expertise, why don't you go over to DiyAudio.com and make your demands directly to Bruno, and tell him why his published specifications (powered by switching supply) couldn't equal or better Nelson's efforts...Personally, I've yet to hear a class D amp that I could live with, which is why I'm looking forward to hearing the Ncores.[EDIT - That being said, I couldn't live with the majority of conventional non-class D amps I've heard, either] My motivation are the comments of a single member of AC, whose system I've heard, and compared notes on components we've both heard in our own systems. Without calibrating respective perceptions, other's evaluations (and cheer leading) are largely meaningless to me.FWIW,Paul
"Not sure any amp design will ever sound as good as a top notch class A setup."Politicians will love that attitude. Nothing like being an ideologue with a closed mind.
I'll use an analogy if I may. About five years ago, I wanted to buy a digital SLR. Working in electronics, I was interested enough to take a closer look at sensor technology so trawled the web. The technical articles at the time concluded that CCD had better dynamic range, hence lower noise than the new-fangled CMOS ones. However, Canon were beginning to use CMOS sensors that were technically inferior but were cheaper to manufacture & faster to read into memory. I re-read these articles then noticed that they were all around five years old & badly out of date. The "inferior" CMOS sensors are now used in most/all mobile phones & DSLRs including so-called professional cameras such as Nikon's new 36MP D800.That EETimes article dates back to Aug 2005. It also goes on about class D as being digital which is plain wrong - they sample the audio band & drive the output devices to be fully on or fully off - all current or all voltage is a useful over-simplification but serves to illustrate how they are as efficient as they are. That MC article is from 2008. I suggest that class D technology has moved forward significantly since then. Having borrowed a recently introduced Primare A34.2 power amplifier driving my nominally 4 Ohm Totem Arros for a week convinces me that class D can not only better class A/B but some day equal class A and use a lot less power into the bargain. The 150 Watt Primare was housed in a non-ventilated case & weighed 10.5kg. Time will tell how reliable this switching technology will be of course. The likes of Leema are also launching class D so I'm far from being in the minority in thinking that class D is not just suitable for "non-critical" portable devices.
....The claims about Ncore being a game changer need to be backed up as to why and how limitations were addressed. So, you no longer question how or why things work? ....
The Ncore papers are pretty straightforward, but really state nothing about overcoming limitations are listed. It just pretty much explains how it works. And, it seems to work pretty well overall. This article explains why switching amps often do not sound as good as they measure;http://www.eetimes.com/design/audio-design/4015267/Why-Class-D-Amplifiers-May-Test-Well-But-Often-Sound-Terrible
Let’s stick to facts about debating operating principals, and leave out the personal nonsense.
Listen Mate, the four year old comment is snarky and uncalled for.
The principal of switching amps has not changed all that much since 2005. Yes, they have advanced, and there are several other classes of switching technologies out there since then as well. The devices used are likely faster, but the principals of operation have not.
However, (almost) all the amps involve reconstructing an input analog waveform. One of the exceptions to this was Sony. Sony had a series of digital switching amps out in the early 2000’s that took a digital input and generated a Pulse Length Modulation (PLM) created analog waveform output. Sony had both a switching and linear power supply setup. These amps actually sounded pretty good for their time.
If you want to learn something, go over to DiyAudio, and ask your questions (nicely) of Bruno Putzeys, and/or others who truly understand the issues.
I haven;t been convinced at this point that class D is any better than tripath or ICE. I think it's probably personal preference. So far, I like the tripath sound a lot. Like all amps, they work better with certain loudspeakers. I don't have one in my main system because my speakers require more current and power. The large CODA amp I use does sound better overall. Of course, that may not be true with a high efficiency speaker design. I suspect so however. I'm sure there are Firstwatt owners that loved their amps, but moved on to accommodate changes in their speakers or preamps. I've only had one ice amp in the house and thought it hard and thin. I'll bet there are others that sound better as well as offering gobs of power.
Concur with your observations. BTW, tripath amps are a variation of Class D. No doubt Class D has a lot to offer in regards to output power and efficiency. The trade off with Class D is achieving overall sound quality that rivals the better conventional amp designs. Given all the switching and filtering involved to re-generate the output analog waveform, it’s not surprising that there is a vigorous debate about the ability of Class D to sound as good as conventional amps. It seems fair to state that the more efficient the amp is, the more challenging it is to get the amp to sound reference quality.
