Atma-Sphere Class D… Amazing

@aw-agd 




 

With all due respect, Silicon Mosfet cannot compete in performance nor on future FOM (Figure of Merit) improvement with GaN based semiconductors, it is not a matter of opinion, it is physics.

Really? Seems to me as a practical matter, silicon mosfet based class d amps by Hypex and Purifi clearly illustrate performance that not only competes with current GaN amps but in nearly all cases I am familiar with beats them handily in most objective parameters. One can argue that GaN devices offer inherent advantages over silicon mosfets, but unless the implementation exploits those advantages, it is all just a marketing scam. To date I have seen many GaN amp's brought to market, few that actualize these theoretical advantages.

@kuribo 

An informative post with alot going on here. First, I admire that you are tackling a pretty complex DIY active three way speaker system. I also admire that you've been a class d amplifier user for over two decades. Especially so given the evolution of class d amplification during that span.

Now that you have communicated you are in the market for six channels of amplification AND that you can afford to purchase anything you want....I'm still not sure that would change Ralph's mind on supplying you the data you require. It might keep him up at night that you might need troubleshooting assistance with your electronic crossover and getting things to sound right.

@kuribo Yes, really. As I said it is physics, not a matter of opinion. However you are absolutely right about the implementation issue. GaN Mosfets are much more challenging to use in order to take full advantage of the intrinsic superior performances. Without a deep knowledge of the device physics and experience with the device package mechanical issues, stray inductance, gate drives and overall layout, any improper implementation can demise terribly the electrical and sonic performances. But that it is also true in general since the same argument applies to the implementation of circuits with Tubes, Bipolar devices, Silicon MOSFET, in ClassA, B, C,D, E, F, G, H amplifiers (all topologies of amplifiers).

Hope my answer is helping in clarifying a bit more the subject.

@ghasley

Not a lot of DIY- speakers are Tympani IVa, so it will be a matter of setting up the dsp crossovers, etc. No doubt it there will be a learning curve. Not sure yet about the amps, obviously. There is a plethora of options as class d has hit it's stride of late...I may look at the new Hypex Nilai500 modules due out soon as preliminary data is quite spectacular. Those would entail a diy build, which I have some experience with so shouldn’t be an issue....

We have Kuribo claiming that only measurements are meaningful and since Hypex and Purifi have the best measurements then they are the best. Then you have Ralph saying it is ONLY certain measurements that are meaningful for sound and his amp has those measurements. Neither one of these people claim that parts and tweak execution are necesarry or important.

Please go to 10 audio.com and read the reviews of the Purifi based amps from NAD and the EVS modified VTV $1000 amp. They both use the same exact module from Purifi......I do some minor mods to the Purifi module.....but it would not measure any different. He describes the sound difference.......quite a bit better with my modded Purifi than the stock implemented NAD. BTW, I am no longer modding amplifiers.....so this is not an advertisement. In fact, you will see all references to modding removed from my website this weekend (I am sure the anti modders are celebrating....he he)

Measurements are great......I think it is better to have lower measured distortion and probably Ralph is correct about the types of distortion. But.....a BIG BUT.......this is just the beginning. I can take any amplifier of any type.....class A, Class A/B, class D.....solid state or tubes and improve the sound in infinite ways that have NOTHING To do with the distortion measurements. I have been doing this for over 40 years. People have sent me their stock digital disc players, DACs, etc. and I have done mods on them and returned them and ALL of them over the years say they now have better sound. It is universal.

If you really want to KNOW anything about what I am saying.....then simply try the transformer mod ON ANY product you have that has a toroidal transformer bolted down with steel hardware. Do you want to be right?.....or do you want to learn something? Do you want the sound you have now or do you want better sound? It will take 20 minutes to take the covers off....remove the steel and place the transformer on a three inch sqaure piece of one quarter inch thick wood. You can even temporarlily use two stacked double thick cardboard pieces Even if you just lay the transfomer down on the chassis the sound would be improved......but it sounds best by getting the transformer away from the grounded chassis.

You could also try an audiophile fuse....(the $200 Quantum yellow for instance). Does it improve the sound.....or will it do nothing as Ralph and Kuribo claim?......Who do you believe? I believe no one. I try things for myself. Do not believe me, do not believe Kuribo, do not believe Ralph......believe what you experience/what you hear. DIRECT experience tells you what is true.....words are just words.....opinions are just opinions.....truth can be known by direct experience only. Are you in LOVE? Do you need someones opinion to know you are in love? Do you need someones opinion to know what something sounds like? I hope not. Be your own Guru.....be your own source of knowledge......A wise man has direct knowledge.....he does not follow others..

We are the infinite light, love, joy and peace of God.....We are also wise and powerful....especially when we let spirit guide our ways of thinking and saying and feeling and doing. May you all create a life filled with the bliss of God.