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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?


celander
georgehifi's avatar
georgehifi
4,966 posts
 
Measurements mean very little.

I’m sick of ill the informed, saying this, all amp designs, are measured, bench tested and listened to, in that order.

ANY!! amp worth it’s salt is designed using all the EE laws of electronics, and then measured/bench tested and listened to.
If necessary then to change the sound, using EE laws again, modded, re-measured, re-bench tested and to make sure all is fine, then listen to again.

Anyone selling you an amp and saying it wasn’t designed and produced using these, I would walk (no run) away from, as he/she will be a voodooist and or snake oil’er.

singintheblues
29 posts
 
I’m an utter tech dummy.   I have no idea what “Fets” & “Mossfets” do & I have no idea if this GaN technology improves the amplifier side or the switching power supply???

...but I did hear a Marantz PM-10 the other week & thought it was superb.   Powerful sound (200w>8ohm, 400w>4ohm) with real clarity.  It has a toroidal transformer, 

https://www.marantz.co.uk/uk/products/pages/productdetails.aspx?catid=hifi&subcatid=amplifier&am...


Anyone here heard one?

RRP in U.K. is £8k, but they’re going used for £4k.   I’m very tempted to go for it.
celander's avatar
celander OP
1,036 posts
 
Marantz PM-10 is a conventional integrated amp. It does not appear to include a class D amp section, let alone a GaN-based class D amp section. So this post is misplaced. This forum thread is focused on GaN-based class D amps.

The GaN-based technology are power FET transistors made of Gallium Nitride. They are used in power output implementations, not in the power supply section.

The benefit of a GaN-based FET power transistor over silicon-based MOSFET power transistors is how well the GaN-based FET transistors track the input signal on square wave measurements. One needs to see a picture of such a measurement to understand this point. The upshot of all of this is that deadtime is reduced, overall negative feedback in the amplifier circuit is dramatically reduced or altogether eliminated, among other things.
ricevs
190 posts
 

George,

If voodoo means listening to things and using the best sounding things then certainly I am a super voodoo lover.

Everything sounds different.  Most things that make a difference sonically cannot be measured.  I just did a listening test of three different female xlr input jacks (Neutik, Cardas and Furutech).  All three sounded different.  All three measure the same.  This is the same for solder, wire, capacitors, fuses, resistors, damping, shielding, power supplies, bypass caps, etc. etc.   All these things make the sound different and yet they all measure the same.  This is from my direct experience of over 40 years of listening tests.  This is why every single amp from every single manufacturer will always sound different.  Believe it or not!  It is not my belief.....it is my BE LIVE......for experience is the direct truth......you have to listen to know!

tweak1
870 posts
 
Perhaps good news for GaN prices. I stumbled across this YT video from CES regarding GaN amp from CREE of all companies. 

https://www.youtube.com/watch?v=gYHY_XKv5tY
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