GaN Amps - Anyone heard one?

[Rexp]

This guy mods classe D amps to good effect apparently:

http://tweakaudio.com/

 

[Sam Lord]

On 7/16/2021 at 7:36 PM, John Hughes said:

I got my Starkrimson today.  

 

I did some volume matching in my room with my VTV Purifi amp using white noise and Roon EQ levels so that everything should be matched within 1 db.  I used White noise and a SPL meter.  The level between the two amps was only about a DB anyways. Using balanced connections.

 

1dB sounds different and for the higher level nearly always gives an advantage when the amps are well below clipping.  If the amps have a pretty even low frequency response in the audio band and somewhat below (not a given), that's an acoustic energy difference of over 20%.  It's really better to use a DMM to measure AC voltage across the speaker inputs, where getting a >0.1 dB match is easy.  But thank you for posting your impressions.

[RichardSF]

On 6/11/2022 at 1:39 PM, John Hughes said:

I have ordered the Atma-Sphere Class D Monoblock Amps.

What is the availability and lead time? I assume that you're still waiting for them. I have seen Ralph Karsten's posts on forums over the years and he has very sensible views about harmonics in amplifiers. He built his business on tube components but now believes that class D and solid state are the future.

[John Hughes]

12 hours ago, RichardSF said:

What is the availability and lead time? I assume that you're still waiting for them. I have seen Ralph Karsten's posts on forums over the years and he has very sensible views about harmonics in amplifiers. He built his business on tube components but now believes that class D and solid state are the future.

I am still waiting, its the transformers that are being held up on supply chain issues.  I suspect once he gets that stock in there won't be much of a wait on new orders.  He does make them when ordered but that normally takes about a week from what I've gathered, its not a complicated build. 

[John Hughes]

On 8/5/2022 at 10:13 AM, John Hughes said:

I am still waiting, its the transformers that are being held up on supply chain issues.  I suspect once he gets that stock in there won't be much of a wait on new orders.  He does make them when ordered but that normally takes about a week from what I've gathered, its not a complicated build. 

I've heard that they have gotten in the transformers, so shipping sometime in the next week. 

[John Hughes]

I received the amps this week, and they are burning in on my system.  I'll comment more after I hit about the 200 hour mark.  But cold from box, I can tell there is some transparency and finesse.  Also, they don't sound rough and glare-y like so many Solid State amps do before they break in. 

[Mike Rubin]

As long as we are on the topic of GaN amps, is there a reason why there are so few integrated amps with GaN modules?  I know of two:  The Orchard Ultra, with only one input, or the Technics at $10k.  I don’t need a DAC built in, necessarily, but I could use a product with more flexibility than the Orchard and less MSRP than the Technics.  Are there others out there that I am overlooking?  If no one is making such a unit, is it due to technology barriers or a perceived lack of need in the marketplace?

[firedog]

7 hours ago, Mike Rubin said:

As long as we are on the topic of GaN amps, is there a reason why there are so few integrated amps with GaN modules?  I know of two:  The Orchard Ultra, with only one input, or the Technics at $10k.  I don’t need a DAC built in, necessarily, but I could use a product with more flexibility than the Orchard and less MSRP than the Technics.  Are there others out there that I am overlooking?  If no one is making such a unit, is it due to technology barriers or a perceived lack of need in the marketplace?

A) I think the chips  are less available and in fewer models for OEM; manufacturers are also more likely to go with what they know, and few know GaN.

B) In spite of the claims, it isn't a given they are intrinsically better than other class D. In an interview here the Purify people explained the pros and cons of GaN vs other types of Class D, and explained why they decided not to use GaN. It's a design choice, like anything else.

As with everything audiophile, marketing claims often try to make it sound like such design choices are intrinsically better, when they may not be. 

[Mike Rubin]

8 minutes ago, firedog said:

A) I think the chips  are less available and in fewer models for OEM; manufacturers are also more likely to go with what they know, and few know GaN.

B) In spite of the claims, it isn't a given they are intrinsically better than other class D. In an interview here the Purify people explained the pros and cons of GaN vs other types of Class D, and explained why they decided not to use GaN. It's a design choice, like anything else.

As with everything audiophile, marketing claims often try to make it sound like such design choices are intrinsically better, when they may not be. 

Thanks for this take.  That makes sense.