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GaN-based Class D power amps

The use of GaN-based power transistor tech is now emerging for Class D audio power amplifiers. Seems appropriate to devote a forum thread to this topic. At least 3 companies have commercial class D amps in their books:

Merrill Audio, with their model Element 118 ($36k per monoblock, 400 W into 8 ohms, 800W into 4 ohms), Element 116 ($22k per monoblock, 300 W into 8 ohms, 600W into 4 ohms) and Element 114 (coming soon). 
https://merrillaudio.net

Review of Element 118 at this link:
http://www.enjoythemusic.com/superioraudio/equipment/1018/Merrill_Audio_Element_118_Monoblock_Amplif...

ADG Productions, with their Vivace Class D amp ($15k per monoblock pair, 100W into 4 ohms). (The designer emailed me indicating he has another product in the pipeline.)
http://agdproduction.com
Review of the Vivace Class D moniblocks at this link (warning: link might not work (1/11/2019)):
https://positive-feedback.com/reviews/hardware-reviews/agd-production-vivace-gantube-monoblock-ampli...

Technics SE-R1 Class D stereo amp ($17k per stereo amp, 150WPC into 8 ohms, 300WPC into 4 ohms) 
https://www.technics.com/us/products/r1/se-r1.html
Preliminary review of the Technics SE-R1 at this link:
https://www.stereophile.com/content/technics-se-r1-digital-amplifier
Technics also has a lower priced GaN-based class D integrated amp in their catalog:
https://www.technics.com/us/products/grand-class/stereo-integrated-amplifier-su-g700.html

Anyone listened to or own any of these amps?


128x128Ag insider logo xs@2xcelander
atmasphere's avatar
atmasphere
7,068 posts
 
What it says is that the Technics amp is not a class D amp......it is a digital amp. IE....it takes only a digital signal and then converts the PCM stream to PWM to drive the switching output stage. The "analog" input on the Technics amp goes through a 24/192 A2D converter to change it to PCM so it can then get converted to PWM.
'Digital amp' is a marketing term. The description above describes a class D amplifier with a digitally controlled front end.
twoch
186 posts
 
The Man Said,
 "Not to mention Class D is most efficient and runs cooler so you save on power bills"
   Sounds nice to many
people   But to me i want sound first  
then worry about Bills
and Heat 


rsf507
405 posts
 
@twoch +1
If you afford HEA you can afford electric bills.
ricevs
190 posts
 

It is not clear whether the cheaper Technics is a digital amp or a class D amp.  I will use these terms because it is very clear.  A digital amp takes the analog signal and coverts it to PCM though an A2D converter and then converts it to PWM.  A class D amp takes an analog signal and converts it directly to PWM.  The only way I found out the larger Technics amp was a digital amp was to read the very clear review I linked to.  

Many would not want their analog signal (using their multi thousand $ DAC or phono stage) to go through an A2D converter).

George,  please use your sleuthing capabilities and find out for us if the Technics converts analog to digital first or not.    I just sent Technics an email asking them.  I also asked Technics if the SE-R1 is even sold in the US as it is not listed on the US portion of the website.  It is listed as sold in Japan.

I finally got a response from Soundigital and they said they are $800 and have warehouse stock in Florida.  You would have to contact a Soundigital dealer to buy it.  This amp uses 12 volt power and has rca inputs only.  Someone should buy it and mod the heck out of it.  Would be a fun project.....I am not volunteering.  

georgehifi's avatar
georgehifi
4,966 posts
 
It is not clear whether the cheaper Technics is a digital amp or a class D amp.


Really??, it's Class-D.
If you need proof under "Design" 3rd paragraph down.
https://hometheaterhifi.com/reviews/amplifier/integrated-amplifiers/technics-su-g30-network-audio-am...

I finally got a response from Soundigital and they said they are $800 and have warehouse stock in Florida.
Sounds like a viable re-badging/re-casing project.
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