# Testing the SounDigital SD300.2D GaN-Fet amplifier (and a reveal in the comments!)



## PPI_GUY (Dec 20, 2007)

This is not a review by myself or anyone I know. But, is a battery of scientific tests (and review) by a user in the forum at the Audio Science Review website that was posted on Nov. 6 of 2021. Testing was done by the user named "amirm" (Amir) who is listed as "Founder/Admin" in his avatar. It's a pretty thorough review with testing data that backs up what many have said about this early example of GaN-Fet technology in the car audio environment. Rather than influence your opinions, I'll just provide the link and let you evaluate the test results on your own...









SounDigital SD300.2D Review (Car Amplifier)


This is a review and detailed measurements of the SounDigital SD300.2D stereo car amplifier. It is on kind loan from a member. Apparently only 200 of these were built using GaN transistor technology. Not sure of the original cost ($1,300?). From outside, the SD300 looks plain and and budget...




www.audiosciencereview.com





Now, as interesting as the test results were, there is a comment posted by Diogo Ianaconi, CEO of HKI USA and Export Director for SounDigital USA that I found equally exciting. He posted the following..."We have big plans for 2022 with the release of 4 new GAN amplifiers. From our initial tests, they are *much superior than our original Limited Edition model.*" 
He also provided a link to the corporate website portal for more info but, I couldn't find anything mentioned there regarding these new GaN based amplifiers. Maybe they are waiting for the new calendar year before making any announcements? 
For those of us who have been following the development of GaN, this may be the first shot fired in what will hopefully be a new era of competitive innovation in car audio SQ.


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## Bikey (May 15, 2021)

I saw that as well. Amir has tested a bajillion audio items and appears to be extremely credible (he is essentially the messenger for the various objective tests).
I also couldn't find any more info on other GaN models from them.
Kind of odd that SounDigital produces extremely low end (e.g., SounDigital SD 600.1D Nano Car Amplifier) and extremely high end amps.


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## JohnnyOhh (Feb 19, 2015)

thanks for posting this. do you guys know what's the benefit from using the Gallium Nitride FETs? it sounded like the switching frequency of the switching power supply was much higher than conventional audio amplifier -> 800kHz with Gallium Nitride FETs. does that help with the audio quality... generally speaking?

i generally remember Gallium Nitride FETs were crazy expensive and used in military applications.


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## Thomasluke7899 (Jan 4, 2020)

JohnnyOhh said:


> thanks for posting this. do you guys know what's the benefit from using the Gallium Nitride FETs? it sounded like the switching frequency of the switching power supply was much higher than conventional audio amplifier -> 800kHz with Gallium Nitride FETs. does that help with the audio quality... generally speaking?
> 
> i generally remember Gallium Nitride FETs were crazy expensive and used in military applications.


Th3 goal with the switching frequency is to get it out of the hearing range. 
So the higher the frequency the better. 
I don't think you'll ever hear 800k


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## audiodelic (Jul 23, 2017)

Never could find one, always wanted one to drive midbass with 300w, one did come on sale in the classifieds few years back.


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## PPI_GUY (Dec 20, 2007)

JohnnyOhh said:


> thanks for posting this. do you guys know what's the benefit from using the Gallium Nitride FETs? it sounded like the switching frequency of the switching power supply was much higher than conventional audio amplifier -> 800kHz with Gallium Nitride FETs. does that help with the audio quality... generally speaking?
> 
> i generally remember Gallium Nitride FETs were crazy expensive and used in military applications.


Higher switching speed, better efficiency, incredibly low distortion, high s/n ratio. In theory a GaN Fet based amplifier could approach real class A in terms of resolution. The problem has been the high cost of Gallium Nitride material and the simple fact that car audio isn't very high on anyone's list of markets where the tech could be profitable.
The only category where GaN wouldn't be superior might be transient dynamics or headroom. Look at the tests in the article I linked. There was a noticeable lack of measurable headroom or dynamic capability. However the SouDigital 300.2D is a older design and as mentioned in the comments section on that page, SD promises new models with "superior" performance. They may have solved the headroom problem.


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## audiodelic (Jul 23, 2017)

Heard great things about this amplifier, no gains/no crossover, great sq.
Hope they release these soon and there is enough availability. Im sure a 6 channel will sell like hotcakes with that foot print and sound quality.


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## audiodelic (Jul 23, 2017)

Gan Technology .. Home Audio


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## UNBROKEN (Sep 25, 2009)

Wow. Not sure else to say. It’s better than I expected and they ran into the limitations of my DSP.3 so I’ll be buying an ultra next week then going back for round two.


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