Class D

https://gansystems.com/wp-content/uploads/2020/05/GS-EVB-AUD-xxx1-GS_Technical-Manual_Rev-200526.pdf

Instead of just posting a link, you may want to actually read it and understand it.  Note the differences between open and closed loop. Note how the closed loop has better performance at low frequencies but the performance degrades quite a bit at high frequencies?  This is a consequence of inadequate design, pretty much as atmasphere has repeatedly stated. Thank you for providing yet another excellent example.

This eval is tech evaluation platform. It is not intended to push the limits of technology or topology. If someone is looking to buy modules and DIY, they would be better served with ncore or purifi modules with significantly better performance.

Please don't be stupid. It is stupid to respond to George.....he is a rock....he will never move from his position.....and he has to have the last word.......so it will always go on and on and on.

@ricevs I get what you are saying, and regret the diversion that this has often caused. Generally speaking, if there is going to be misinformation on any given thread about class D on this website, the chances are very high that it will be coming from George.


Now I could sit back and watch him do that; I have a theory that a rising tide raises all boats. So knowing the truth of the matter should I sit back and do nothing? We've all seen in the past when someone passes misinformation as truth that it is possible that everyone will suffer. OTOH if I do respond, it looks like I have a personal beef with George which I don't - I've never met him. So this has been an on-going dilemma for which I've never felt I've had a good solution.

atmasphere, ricevs:

I don't try to hide that I think a lot of "tweaks" are highly questionable, and as opposed to what many believe, I have had a large group of audiophile friends who over the years have tried them, so I have been exposed first hand to them, and see difference in blind/sighted listening. Some, based purely on the claims, are physically impossible. I know stating that irks someone.  Almost never has anyone ever come back with truly empirical evidence to support their position, even if they resort to "I can trust my ears". I do find leaping from "I trust me ears" to "it must be true" distasteful, almost as much as "I like it", therefore "it must be accurate", however, those argument and conversations play out much differently from this.


We are not "arguing" over likes, or personal impressions. We are discussing hard, factual engineering topics and concepts. These really are effectively black and white topics, and there is an absolute right or wrong.  People who obviously have a deep and accurate understanding of this topic post detailed explanations and why things are the way they are, work the way they are, etc.  We don't sugar coat, of exaggerate.

In the face of that, someone else, with clearly an incomplete and inaccurate understanding of many of the related topics to Class-D repeatedly posts technically erroneous information. This is not even debatable. It really is black or white, right or wrong. They are wrong. Absolutely provably wrong, and they have been. They don't recant, or consider they may be wrong, they double down and repeatedly post false information labelling it as factually correct, even though they cannot describe it in their own words or justify their position.

Last, I find the repeated personal attacks on atmasphere totally uncalled for. It is like he has a personal grudge.

To others that care about these forums.

All we have are manufacturers and their shills, with incessant agenda to get he ball rolling on their latest class-D products, and they use these forums to slyly advertise what they have coming up for sale, and will stop at nothing to counter anything that may effect those future sales.
See the immediate angst cause to them with the professionally ready made diy GaN Class-D kit I put up above, which is probably better than anything they could do.

One here especially put rubbish on the new GaN transistor technology way back when I showed it to all here, and he said it has no advantage over the Class-D technology used.

But now he’s has changed his tune and is actually pro GaN transistors, funny what the mighty $$$$ brings out in people. Like I said they are just here to slyly advertise their goods. You can’t believe them, especially the fusers!

At least companies that use GaN like Orchard Audio, AGD ect don’t come here behaving like them.

Cheers George

Here are some interesting developments....

1. Class D audio (under the Premium Audio name) will soon be releasing their "baby" GaN amp.......stereo, 150 watts a channel into 8 ohms, balanced and unbalanced inputs for a mere $699.  100K input impedance.  You will see a tiny bit of info here....wait for the second slider to load to see the pic

https://premiumaudioproducts.com/


2. Orchard Audio is releasing a higher powered version of their GaN amp module.  You can buy the module fully loaded or you can just buy the board and buy all the parts and stuff it yourself.  This new 250 watt a channel module has higher input impedance (44K balanced) and higher gain then before so makes it more universal.  The unloaded boards can be bought for $100.  The stuffed boards can be purchased for less than $1000 the pair (till the early bird sale goes away).  This would be way better than the eval board put out by the GaN companies.....The Orchard amp measures and sounds very, very good.....800K switching and very very little phase shift. 

https://orchardaudio.com/shop/ols/products/strk-ltr-mdl/v/STRK-LTR-MDL-SSMBLD

The phase response and other measurements of the earlier less powerful module can be seen at the bottom of this page.

https://orchardaudio.com/bosc#58053fe9-04a5-4030-9e69-e310ee3f6b5a