Atma-Sphere Class D… Amazing

@docroasty

Thank you, that's good to know. Weird, about the power meter led - it seems to be quite common, although I read somewhere that Carey did fix the issue back in 2018 or thereabouts.

Does the quote above suggest Alberto (AGD) is misleading in his saying his GANFET is made for audio?

No- not in my opinion. IMO it suggests he had a batch made that have low output capacitance. Low output capacitance reduces ringing in the output section (which is also caused by circuit board trace inductances and power supply issues- they can be in parallel with the output capacitance of the device which results in ringing and noise) as it switches and thus helps the devices to run cooler. The ringing can be controlled by a snubber filter but the output devices will still run hotter. So a low output capacitance is desirable.

In practice we found no need for a snubber circuit as there was no detectable ringing. IMO GaNFETs allow for lower noise designs. I think this is very important as switching noise and parasitics can mess with digital equipment even it the amp meets EU emissions directives. So you want to be many dB below the maximum allowed by most government entities. We found that many tube amplifiers radiate more noise than our class D.

Thanks for responding @atmasphere. In a interview, Alberto says he was involved in the initial development of GANfet. I believe he said he bought the stock and patent for the Mosfets he uses. 

A brief history of gallium nitride (GaN) semiconductors

The Class D monos arrived yesterday and are hooked up and have played for nearly 9 hours. System information:

Auralic Aries G1.1 streamer > Bela Canto Dac2.8 AES/EBU input > A-S Class Ds. via XLR input. Interconnects are DH labs (DH-110 and Air Matrix Cryo). Speaker cables Kimber 12TC. Speakers are Totem Forest Signature.

Simply put, this is the best amplifier I have ever had in my system - the only two that come even close are the Pass XA30.8 and the Benchmark AHB2. There is a wholeness that makes it seem trite to analyze the sound spectrally in terms of highs, mids and lows. To use an imperfect analogy, some writers’ prose is so "perfect", that you get a sense that their writing is inevitable and that any change to it can only be for the worse. I am no literary critic, but I recognize it when I see it (Ian McEwan comes to mind, sometimes Paul Auster, always P.G. Wodehouse). To my ears, these amps have a sense of rightness, a wholeness that transcends anything I have ever heard.

Truly, a more fitting name for a brand could not be devised - I’m sure many of you know that the name is a play on the Sanskrit word for soul - Atman or Atma. If these don’t get to the soul of music, I don’t know what else does.

@atmasphere, I only regret that it took me decades to finally stumble into your work - well, I am here and here I intend to stay. This is inspired work on the part of you and your team.