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Congratulations Atmasphere!

I noticed today that Ralph Karsten (whom regular and even occasional participants in this forum will of course recognize as the designer and proprietor of Atma-Sphere Music Systems, as well as a uniquely valuable contributor to the forum) was granted United States patent number 10,469,042 on November 5, 2019. It covers an audio amplification technique he had indicated here that he has been developing, which in simple terms appears to me to basically be a clever combination of an analog-to-pulse train converter (as used in traditional class D amplifiers for example, among other audio-related applications), with an output stage employing circlotron topology (analogous to the topology used in his OTL power amplifiers, but utilizing solid state devices).

Link to the Patent.

Congratulations Ralph!!

Best regards,
--Al


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erik_squires
16,295 posts
 
@almarg Thank you.  So long as we all agree you were being completely unreasonable. :)
audiokinesis
2,749 posts
 
Ralph has a uniquely thorough appreciation and understanding of "what matters to the ear". My mentor Earl Geddes (with Lydia Lee) had a pair of peer-reviewed papers on distortion perception published in the Journal of the Audio Engineering Society. Their findings backed up everything Ralph had been telling me. In fact after writing the papers Earl remarked to me, "now I understand why you and your friends like tube amps".

I think we are extremely fortunate Ralph has chosen to pour himself into designing a switching amplifier that actually works with the characteristics of human hearing instead of against them. We may be about to see switching amps that do not have the traditional drawbacks of switching amps.

Right now I’m really glad I’m a speaker designer instead of an amp designer, because I would hate to compete against what’s coming.

Duke
yeah, I’m also an Atma-Sphere dealer
timlub
2,041 posts
 
You guys know that I've been a speaker builder for many years.  Through my struggles in the amp forums here,  the past couple of years, I have built modified and repaired several amps to improve my knowledge.  My studies on circlotron started with Jim Bongiorno and the old Sumo Nine.  I have a highly modified Nine which is very good.  Then looked at how circlotron worked in tubes and how it was modified to work OTL.  
So,  If I understand what Al has written,  Ralph has created a symmetrical bridged class D tube amplifier.... Of course, I'm guessing, but I'd love to hear more. 

Can Ralph or Al expand on this?  Very interesting indeed. 
almarg's avatar
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almarg OP
9,670 posts
 
@timlub 

Hi Tim,

Thanks for the mention, but of course my knowledge of the design is limited to what is said in the patent. And the Abstract at the beginning, supplemented by the figures (especially the first three) seem to me to present a good concise overview.

Regarding your mention of tubes, the figures depict a circlotron output stage that is FET-based, and I suspect that is what Ralph has been developing. I note, though, that the second of the 20 claims broadens the scope of the patent such that it also encompasses tubes as well bipolar transistors when used in a similar configuration.  

Best regards,
-- Al

terry9
2,353 posts
 
Well done, Ralph. And thanks, Al,
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