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Which Class D Amplifier? PS Audio, Ghent, Nord, Merrill or other???

I’m looking for a new amp & want Class D.

I’ve seen various brands mentioned, such as PS Audio, Ghent, Nord, Merrel to name a few, but I’ve not heard any of them.

Which company is producing the best sounding Class D?
Which models should I be looking to demo?


Thanks



singintheblues
georgehifi's avatar
georgehifi
10,312 posts
 
George, looks like you made my point.

As Steve Colino of GaN (EPC) has said below, there is no need for any heatsink on the GaN transistors if they are used at todays switching speed. Only if you use the option to raise that switching speed to gain the extra sound quality, then there is the need for a heat sink to be mounted to the GaN transistors, as in the Merrill and Technics case.
Once again you twist things, "it’s not a good look" if you try to put s**t on this new technology while your trying to release your own Class-D amps.

Excerpts from Steve Colino’s email to me.

V.P., Strategic Technical Sales

EPC (Efficient Power Conversion Corporation)


"EPC9106 GaN FET we were able to get outstanding sound quality in the amplifier without heatsinking.
Our GaN FETs will give an even higher performance difference compared to MOSFETs in both sound quality and efficiency at 1.536 MHz switching speed.
The eGaNAMO2016 is a GaN FET amplifier platform that is capable of delivering a very high performance 200 W into an 8 Ω speaker load (400 W into 4 Ω) [8]. Its 96% system efficiency without requiring a heatsink.
You can take the value in sound quality and eliminating heatsink assembly costs while delivering your customers increased efficiency is a smaller form factor."


https://www.digikey.com/product-detail/en/epc/EPC9106/917-1090-ND/5036827
" THERMAL CONSIDERATIONS With this high efficiency, the EPC9106 design allows for the complete removal of any classical or historical heat sink requirement. This elimination of the heat sink also reduces the potential contribution to radiated EMI/EMC emissions.


noble100's avatar
noble100
2,419 posts
 
Mapman: " Also I do not hear the issues George claims even at this modest cost."

Reports from those who do hear issues, with class D or T, are scarce. Rumor has it that georgehifi’s real father is an Australian sheep dog, perhaps he can hear dog whistles, too.
I’m still waiting to learn from georgehifi exactly what these supposed class D sonic shortcomings actually sound like. His very rare previous descriptions were so vague that they’re meaningless.
Has anyone else claimed to hear these issues besides him? I don’t recall anyone else chiming in to claim they hear issues with class D. I faintly recall a single poster, who didn’t have a user name of georgehifi, claiming they listened to some D amps stating that ’something was missing’ or ’it lacked soul’ but nothing specific that could be relied upon with any confidence nor even be considered a corroborating anecdotal description since I believe this was claimed only by a single poster.

Tim
michaelgreenaudio's avatar
michaelgreenaudio
1,019 posts
 

Actually not to take sides with anyone, but I have heard the sound that George mentions. However I hear this problem with all classes of amps, who use certain chassis. Chassis can and often do play a role in mid and upper end distortion. So do transformers being to close to caps.

If you take your amp (any amp) apart and spread out the components you will be able to find the distortion cause by component cramping.

Class D amps in their little squeezed boxes have problems, but also problems come with these smaller boards used.

I like Class D a lot, and there are lots of advantages over A and AB as far as mass goes obviously but there are more steps to take in the mechanics of most of these amps that have a ways to go. I'm working on a few of these issues as we speak and can say with almost certainty the amp I will use for our Rev Combo will be Class D, the low end amp already is Class D.

Again a very important thread, minus any absolute opinions. There's good in all but sometimes we over look the simple things when designing.

Michael Green

noble100's avatar
noble100
2,419 posts
 
Hello Michael,,

     Very nice post with some very interesting information and thoughts from a system tuner's perspective.
     As a layman, I think it's an important reminder that designing and engineering a good sounding audio amp, regardless of type, requires making many good smaller decisions (based on one's knowledge, experience and goals) all contributing to the final amp creation's sound.
     Designing very good class D amps seems to be especially difficult since amp designers must make decisions based not only on their acquired experience and knowledge of traditional amp design but also must gain experience and knowledge of how to incorporate the newer and higher performing component parts into their designs.
Thank you,
   Tim
celander's avatar
celander
1,503 posts
 
Tossing arguably superior circuits or eval boards into a box will not likely make for a superior product providing a lasting satisfaction. Designers care about circuit board layout, trying to minimize circuit trace paths from RFI and noise perspectives. And then there are the vibration control and global noise/RFI isolation and reduction issues that come into play.
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