Class D is just Dandy!

@georgehifi

And no one is more invested in making sure they know you don't like Class D than you are.

Best,

Erik

10 years ago class D had already been around for a while, but back then they weren't bringing home the bacon against the prior art. But it was obvious even ten years ago that it was a rising star.

In the last few years though its become a technology to be taken seriously. So about a year ago we began working on our own design.

Despite this, I can't call it a mature technology, a since price/performance curves define what is mature, and the technology is still improving at a rapid rate.

The major problem, as George points out, is the switching speed, but in recent years that is a problem that is fading. Part of the issue of switching speed has to do with the introduction of dead time, which makes distortion. But there have been a lot of advances in relatively cheap semiconductors recently, and the result has been that for a given switching speed, there is less dead time required because the newer devices are so much faster.

This means also that higher switching speeds are showing up.

Somewhere in this, a threshold is being crossed. We see this with the many responses on this thread. Class D, while like any other technology that has its better and worse executions, has arrived.

Its my opinion that any amp manufacturer that ignores the implications of class D is doing so at their own peril.

Looks like our first patent in the field will be filed soon...

Nice summary of benefits of GaN for class D implementations:
https://www.eeweb.com/profile/alex-lidow/articles/how-to-gan-egan-fets-in-high-performance-class-d-audio-amplifiers

Class D clearly has even more potential although given the article was written in 2014 I struggle to understand why this tech isn’t more prevalent today. Am curious to open my amps and check the components but given the heatsinks present I suspect it’s not based on GaN tech. In any case I smell the roses and class D has come of age.

Cheers
Phil

tweakjunky
I struggle to understand why this tech isn’t more prevalent today.

Because mainstream semiconductor manufacturers like Motorola, Hitachi, Sanken ect, haven’t tooled up for it yet, probably because the inventors of the GaN devices EPC (a small company in comparison) I would say have a provisional patent on it, who were if you dig deeper from what I’ve found maybe also the inventors of the Power Mosfet transistor as well way back.
And are now maybe waiting for the best offers from the big boys above. Till then they are probably happily supplying in small numbers to Technics for their SE-R1 poweramps.

tweakjunky
Am curious to open my amps and check the components but given the heatsinks present I suspect it’s not based on GaN tech.

Only the $20k Technics SE-R1 has them so far, and you need connections to get one.

PS: Just dug up the link to EPC being the co-inventors of the HEXFET power MOSFET back in the day.
https://epc-co.com/epc/AboutEPC/Team.aspx


Cheers George

I have tried a several Class D amps over the past 18 months.  I have owned a PS Audio HCA-2, Classe Sigma 2200i, Lyngdorf TDAI 2170, and now have an Esoteric I-03 integrated.  

My ranking in in order of preference is:
Esoteric I-03
Classe Sigma 2200i
PS Audio HCA-2
Lyngdorf TDAI-2170

I can’t imagine ever imagine getting rid of the Esoteric!  Wonderful imaging, dead silent, and tons of power.  This 68 pound tank blew me away compared to the other three Class D amps I’ve owned, or any of the other amplifiers I have auditioned/owned for that matter.