Direct DSD256-raw signal input to GaN E-mode HEMT Class-D audio amplifier.

[Bunpei]

Professor Yamasaki of Waseda University and Bunpei tried applying not PWM but PDM (usual DSD) to an evaluation board provided by GaN Systems and preliminarily obtained a prospective results.

Please read this post if you are interested in DSD;

http://www.diyaudio.com/forums/class-d/323714-direct-pdm-input-gan-mode-hemt-class-amplifier.html

[Bunpei]

Hi, jabber!

 

I appreciated your comment!

 

This board is not indicated as “Class-D amplifier” by the manufacturer. They just say “Optimized for Class D Amplifiers”. In this context, you are right.

On the other hand, as for the definition of the “Class D Amplifer”, Wiki says “the amplifying devices (transistors, usually MOSFETs) operate as electronic switches, and not as linear gain devices as in other amplifiers.” I understand an ADC module is not essential. Moreover, I was surprised that there is a member who sticked to an analog input in this forum though it depend on his sense.

 

Professor Yamasaki and I are “full-digital” orienting audiophiles” in a sense.

[Bunpei]

On 6/13/2018 at 7:24 AM, Maldur said:

If I remember correctly, in Japan some entusiast tries that concept in about 2011, with DSD64 input signal. Volume regulation was done via high quality regulated power supply, where increase or decrease of power voltages changes the volume level.

 

Yes, your memory is correct!

I asked Professor Yamasaki about that. He said, “applying GaN E-mode HEMT as a high-power switching device for 1 bit delta-sigma modulated audio signal this time might be the first trial”.  He added, “Realization of such a simple & compact and energy-efficient class D audio amplifier is very valuable”.

[Bunpei]

On 6/13/2018 at 5:51 PM, Miska said:

Sounds similar to what Estelon LYNX speakers are doing... But Estelon has their completely own amplifier.

Thank you very much for the information.

They say just “FET”. I am eager to know whether their device is of Si based or GaN based.