I recently picked up a new NCore based integrated amp and the matching SACD player. I’ve had all varieties of amplifiers including class A, AB, B, C and D (including tripath by Bel Canto & PS Audio, ICE Gen 1 by Bel Canto & Hypex UcD by Resolution Audio). My favorite amps were my PS Audio BHK 300 followed by the Gamut D200 MK3. My NCore integrated is very close though. It is dead quiet and has vice grips like control over speaker drivers. Admittedly, class D has room for improvement in the area of high frequency response but it is the future.
The analogy I would draw with Class D amps is that of electric vehicles. They too still have a long way to go in development but have attributes which indicate real promise. Premium EVs have great acceleration and a very low center of gravity. Still, faster charging times, lower weight and longer ranges are needed. Premium class D amps are quiet with a very high level of driver control in the form of a very high dampening factor. Still, more range is needed from their upper frequency response.
The Ncore amplifier and SACD player combination have proven to be fantastic together. Wouldn’t have thought the high resolution of DSD would be a good match with class D amplification considering its high frequency response characteristics. They makes beautiful music just the same.
I am inclined to agree with you there. Because of the need to eliminate the switching frequency the signal has to pass through a low pass filter which means that the frequency response starts to roll off shortly before 20Khz. This means that Class D is less effective for digital music at higher sampling rates (although we are not supposed to be able to hear above 20Khz). I suspect that in the future Class D may use even higher switching frequencies, which currently are problematic, and more complex output filters. This would extend their frequency response into the supersonic region.
As the owner of both a fully electric vehicle and a class A Class D digital hybrid amplifier, I think the mistake is comparing them to old technology (class a/b and gasoline). Sophisticated switch mode power supplies have massively higher switching frequencies, it’s just not and issue. What sounds odd at first is that the noise and distortion is so low, and the transient power.
The analogy with cars breaks down because although we use the electric car 90% of the time, we also have a small and cheap petrol car for long trips or when we go in different directions.
If I spun discs, I would go for one of the Marantz combinations like yours. They seem to have a stellar reputation for sound quality and build.
don’t forget class C
more often found in radio transmitters for sure, but Quad’s “current dumping” design is a class A/class C hybrid and still sought after by some.
(happy to be corrected here but looks like it to me )
I used to own Gamut d200mk3 before I bought d250 mk3 monos. I still own them and sound difference going from stereo to mono pairs was huge,totally different amps. So much more detail,ease,bass power, all of it… I still think those Gamut´s are the best amps I ever had.
Confession to make…I also tried Devialet 200 and didn´t like it too much back then,and Tact Lyngdorf Millenium mk iv. Now that Lyngdorf was great. To my surprise it had better top end than my Gamuts.
Oh well,so many class a/ab/d amps went against Gamuts and they ruled always. Still do,though i use BHK250 now If Gamut and BHK were married…perfect ! But so far nothing can touch their speed ,resolution, depth and width of soundstage and tonality. That´s what just one transistor per ± side does,not 32 or whatever and huge transformer and caps. Then why I use BHK? well…I´ve listened Gamuts for close to 15 years or so,time for a change every now and then
I’m on their email list, and they were running some nice specials last summer. I just wish I had
the money to pounce! Be sure to sign up for their email promotions…
I ran across a Peter Lyngdorf You Tube Interview end of 2019 He still believes the Millennium Class D to be the best they produced period of all the companies he is involved with. The power supply is what he was giving accolades. I am still running my bedroom system of a Lyngdorf TDAI 2200 and used it for my main system last May and June while my amps got refreshed. Hard to argue with that amps quality which is quite close to the Millennium. The current is pretty high but not to my big monoblocks abilities. The noise floor let’s one hear everything with the Lyngdorfs and sound stage width, depth, and imaging is really fine. If I had lesser speakers to drive or decided to Triamp the Millennium would be the ticket. Nobody sells them if they own them these days.
My friend bought Millenium mk4 back then, special made model with different impedance characteristics etc. to his own specs to match his speakers. The end result was far better than stock we listened at first. He also had special request for Lyngdorf when they build it and went like this: please make it better than Gamuts Well they succeeded in some areas
My NBS class D amps have Hypex boards with Godzilla power supply features and sound very nice to me. My Class A amp doesn’t diminish my memory of the NBS amps. They are easy enough to hookup when I want to hear them again.
From memory of the 1975 article in Wireless World, the Quad ‘current dumping’ amp was a Class B amplifier with current from the output stage driver transistor being fed forward to the output to compensate for the dead crossover region. A Class C amp only amplifies over half a cycle, and needs a resonant circuit on the output, to provide gain for a single frequency; hence its use in wireless transmission to take advantage of its high efficiency.
The December 1975 paper by Mr P J Walker published in Wireless World is reproduced in the Quad book on pages 195 and 196. Which is fine, if you know the first thing about electronics!
I was lucky to receive this book for a recent birthday -
Lots of interesting techy info and some of the same autthors I see in “Sound Recording Practice”.
Also, I’m now imagining a guitar FX pedal that has a class C amp with a pedal-variable resonant circuit on the output (with appropriate buffers around it) - might make an interesting “Fuzz” and “wah-wah” combined
Where’s the patent office phone number again…?
I got a pair of Mozart socks, but looked the wrong way you could be forgiven they were Father Christmas. Most of my birthdays are an exercise in futility, the wife trying to get me to dress with even a hint of style.
and didn´t like it too much back then,and Tact Lyngdorf Millenium mk iv. Now that Lyngdorf was great. To my surprise it had better top end than my Gamuts.
Well they succeeded in some areas 
