Just got mine last week. After 24 hours of play all I can say is that this is not your father's class D amplifier. There is not one thing about its sound that reminds me of the class D gremlins that I do not like. The low end filled in and now has deep impact, the midrange is the love child of a beautiful tube and clean hybrid amp - just gorgeous. Highs are very clean and extended. Spatial cues are top notch. My system has had some damn good tube and solid state amps in it before and it has never sounded this good. I am blown away with the quality of sound coming from class D amplification at this price point.
Don't expect to get respect from Bruno when he knows what he is talking about and you do not. Hysteresis in the inductor is just yet another form of non linear distortion, like any other distortion. If you apply negative feedback it gets reduced by a compensatory amount, and his amps have a lot of feedback because the can.
The inductor is in the feedback loop, hence any hysteresis distortion is drastically reduced by the feedback.
He is not saying it does not exist at some point in the circuit, he is saying that he effectively eliminates its audible effects, which is self evident from the distortion measurements.
You just learned about hysteresis distortion tonight from the articles I shared. And you're already an expert!
@mivmike -- you didn't even know how to use it 3 days ago, sure your stuff went up ...
Yeah I've only had the unit for 3 years and designed several products with it. But someone who's never used one before knows better. And before I bought one I worked with people who did.
Don't expect to get respect from Bruno when he knows what he is talking about and you do not. Hysteresis in the inductor is just yet another form of non linear distortion, like any other distortion. If you apply negative feedback it gets reduced by a compensatory amount, and his amps have a lot of feedback because the can.
The inductor is in the feedback loop, hence any hysteresis distortion is drastically reduced by the feedback.
He is not saying it does not exist at some point in the circuit, he is saying that he effectively eliminates its audible effects, which is self evident from the distortion measurements.
I told Bruno the only way you would know if you got rid of the hysteresis in a ferrite coil would be to A/B his coil with an air core coil and listen. This is how you know somethng.....by actual listening tests......not by a made up measurement test that has no basis in sound quality.
Measurements are objective, they have no bias. They have a basis in reality, unlike subjective listening that varies from person to person. If there was one best sound, there wouldn’t be so many different and successful amps in the market place. Your idea of good sound is just that, your idea. It has no basis in reality for anyone else. Eye witness testimony has been proven time and again to be unreliable. Your ear witness testimony is flawed for the same reason. At least Bruno delivers an honest product that delivers as advertised, rather than some magic guru fantasy tweak that simply, at best, just adds more noise to the signal.
If Bruno listened to everything he did and was all knowing.....then maybe not. He does not listen to everything he does and is not all knowing.
Bruno produces products that amplify a signal as cleanly as possible. If people like distortion, they can add it themselves in any flavor they prefer. He doesn't push his subjective tastes on others and claim he knows what sounds "best" -he isn't all knowing but he does know that. I can't say the same for you.
So now we are down to my module is better than yours......what are we...children on a playground? "my dady can beat up your dady" What i am always saying....is that there is more. always more. If you gave me your Frankenstein front end circuit....I could mod it and make it better.....so could a whole host of other people. You do not know everything......no one does. There are tons of people who can improve on what I do. What I do is the result of over 40 years of listening tests and making products and modifications. However, it is but a grain of sand in the knowledge of all things audio......plenty of people know more than me......plenty.......but, my overall knowledge is very, very high......and what I do is appreciated by most everyone......I am in service. I love everyone.
The new Purifi module should get delivered in Dec. Warren at VTV has some Beta ones and says they are a noticeable improvment on the baby one. It makes sense....it has more capacitance in the power supply, a larger output coil, more connector pins in parallel for more surface area and lower impedance and has more current capability so will drive lower impedances even better. Even with a simple non low impedance speaker load Warren thinks it just plain sounds more "real" This is a good thing.
I did my homework......in fact, the article you refer to was a retort to an email I sent him. He claims his super feedback gets rid of hyteresis and to prove it he created some test that proves nothing (except a measurement). What do you think?....instead of quoting him.....since he says basically nothing. BTW even all ferrite core coils sound different from each other. If you made the very coil he uses out of purer wire it would sound better.....if you cryoed it....it would sound better. If you use a toroid coil instead of an incased coil it would sound different. So, what is the best? Did you do extensive listening tests to coils to know......or do you believe all coils sound the same? I told Bruno the only way you would know if you got rid of the hysteresis in a ferrite coil would be to A/B his coil with an air core coil and listen. This is how you know somethng.....by actual listening tests......not by a made up measurement test that has no basis in sound quality.
This game is so much more complicated than a simple measurement or a guess. You have to listen to everything you do......to really know if what you "think"...is what is "real"....and what is real in audio.....is what sounds most transparent.....and only the ear can judge that.
It is the peak of stupidity to think that you cannot swap a few parts and improve something Bruno designed. If Bruno listened to everything he did and was all knowing.....then maybe not. He does not listen to everything he does and is not all knowing. It is stupid to think otherwise.
Obviously, you "only Bruno is God" worshippers think as you do. I think everyone is God.....so I worship everyone. Every thing and every person contributes to the whole. All souls are pure and lovely.....knowledge is vast and infinite....no one person can hold it all. We need each other......Tweakers need engineers....Engineers need tweakers. We are one....most holy ones.
So what in the Purifi module makes it have less hysteresis distortion? The NC500 and the Purifi use the same FERRITE core coils.....and the Purifi have STEEL leads on their output caps. What Bruno claims is that there is so much feedback around the coil that it "gets rid" of the ferrite/steel sound. The Purifi has even more feedback than the NC500. What do you think, oh all knowing one?
I admittedly read the graph wrong, however, you may want to reconsider making libellous statements like this:
Either way Amir should have used that THD+N vs frequency @ 5w test in the Topping review, with the Hypex, Purifi and Benchmark amps overlaid in the background. But that would be poor marketing for his partners at Topping. Which means less commission for Amir from the sales generated by the review.
There’s a 20dB difference in noise and distortion at 5w between 1khz and 15 with the Topping!
But still the 2nd best amp in the world according to your mentors.
@mivmike, there is a 15-16 db difference with the Hypex. 20*log(0.15/0.025) = 15.6db. That is not much different from 20db w.r.t. distortion. Amir does not know nearly enough to be a mentor to me, and there are many on ASR with more knowledge and experience, all of which is meaningless. This is about your posts.
I could be your mentor if you took the time to understand what I am writing. Here is another mentoring for you. The Topping is -75db distortion at 5W, 15KHz. That is 0.017%. That is almost exactly the same as the Hypex at 0.015%. At lower frequencies, the Topping is even better than the Hypex. Of note, the ASR graph is 45KHz BW, so after about 10KHz, the THD will not be audible to anyone, and for most here I expect that will be the case at close to 7-8KHz.
The Hypex graph above is at one power level, 5 watts or about 1% of it’s output. There is about a 15-16db change from 200-20Khz. I don’t know what is happening below 200, seems all over the map. Even at 5W, the Topping only has about a 20db change from 20Hz - 15KHz. That is not much different from the Hypex.
If you test the Topping at 1%, or about 1W, then it has only about 2 or 3db change over 20Hz - 15KHz. That is quite a bit better than the Hypex.
You could choose to stop posting stuff that gets holes blown in it. Or not.
Obviously I understand that one is power vs distortion at multiple frequencies measured individually. And the other is THD+N vs frequency over the entire bandwidth. Which is a very useful test that should have been included in the Topping review. But it wouldn’t have been pretty. There’s a 20dB difference in noise and distortion at 5w between 1khz and 15 with the Topping! Only 20dB? 20dB is loads! with the Hypex it’s flat as a pancake. And thats a 10 year old amp design!
And with the Topping by 50w output its a 35dB spread! Horrible performance!
But the Topping is still the 2nd best amp in the world according to your mentors.
Hypex and Purifi offer quite a bit of performance data on their amp products, much more than most.
They do- and are the exception rather than the rule. Bruno uses a self-oscillating technique where the phase margin of the circuit is exceeded by all the feedback added- and so goes into oscillation. The oscillation is then used as the switching frequency- and the triangle wave derived from it. So that allows for 50dB or more of feedback even at 15KHz. You can see this in the distortion vs frequency curves.
The Hypex graph above is at one power level, 5 watts or about 1% of it’s output. There is about a 15-16db change from 200-20Khz. I don’t know what is happening below 200, seems all over the map. Even at 5W, the Topping only has about a 20db change from 20Hz - 15KHz. That is not much different from the Hypex.
If you test the Topping at 1%, or about 1W, then it has only about 2 or 3db change over 20Hz - 15KHz. That is quite a bit better than the Hypex.
You could choose to stop posting stuff that gets holes blown in it. Or not.
Would there be harmonic distortion from a 15khz tone that humans could hear or a band limited amp would amplify?
@djones51No. The reason that tone is used is to look for intermodulations. Those can be quite a bit lower in frequency depending on what other tones are used in the test. How well it does with this test can say a lot about how relaxed/easy going the amp is to listen to since intermodulation distortion is very audible.
The point of the 15khz tone is to see if the amp struggles with those frequencies. As most amps have a much harder time as the frequency climbs above 1khz.
I seriously doubt any class D amp would 'struggle' with a 15KHz tone. If they are at all competent, the amp would just sit there and do it all day.
I agree with the rest of this quote though- most amps have insufficient feedback owing to insufficient gain bandwidth product to support the feedback at higher frequencies- so the distortion often rises above 1KHz (contributing to harshness and brightness). I think this might be why distortion is often measured at only 100Hz, so as to cover up that issue. I agree that the spec sheets are mostly marketing tools because they almost never tell you any of the more meaningful information, such as you pointed out above ('...THD+N vs power vs frequency over a 20-20k bandwidth'). Such a graph would instantly show who has the gain bandwidth product and who doesn't. Heaven help us if the spec sheets actually showed something useful...
And the only thing ASR sycophants care about is 1khz SINAD.
Try as I might, I can’t fathom why you come to this forum to piss and moan about what is going on at a different forum. If you have an issue with ASR and the owner, why aren’t you over there ranting? I don’t, and I am pretty sure most others don’t, care about your issues with ASR.
Just noticed that Amir deleted most of my likes from my old ASR profile. He was so jealous when I had more than he did.
I was one of the original members back when the forum was dead. It was me who told him how to increase the traffic to the forum. It was only because he took my advice that the forum is where it’s at today. But when I seen his true motives, I had enough.
I’ve known Amir for 6 years. Long before he started ASR. He made me my own section on his previous forum "what’s best forum". Because I quadrupled the amount of traffic with my posts. But then he got banned from his own forum from his own partner!
I was one of the original members back when the forum was dead. It was me who told him how to increase the traffic to the forum. It was only because he took my advice that the forum is where it’s at today. But when I seen his true motives, I had enough.
@mivmikeare you just upset they kicked you out? I read that thread, it looks like this is the 3rd of 4th time. It seems you get no love from the people there.
The sychophants, will often do further analysis on the data posted, compare to others, etc. If your attention span is one graph, you should not get angry at others, but look to yourself.
And the only thing ASR sycophants care about is 1khz SINAD. Here’s the holy grail for them. The best way to land sales is to keep the consumer dumbed down to only needing to understand 1 number.
If Amir really wanted to educate people. this chart would be of THD+N vs power vs frequency over a 20-20k bandwidth. But his Chinese partners would have a harder time winning that game.
In case anyone cares, since Mike is too lazy to read the full test or understand the measurements, here is what is in it:
SINAD at 1KHZ
SNR - 20Khz (for these two, it s noted that the gain is only 19db which improves the result)
32 tone multi-tone IMD, far harder than 1KHz + 15KhZ. This spans from 20Hz to 20KHz, and if you know how to read it, you can see the impact of harmonics from multiple tones.
FR into 4/8 ohms
High frequency unattenuated switching noise
1K-20KHz crosstalk
THD+N from 50mW to 100W at 1KHz, 4 and 8 ohm, 45KHz at 20Hz, 500Hz, 1KHz, 5KHz, 10Khz, 15KHz.
Has @mivmikenever read past the first page or does he not understand the rest of the measurements?
I would be really interested if you could show that they make even a 10th of a dB difference to the noise floor. In practice that seems difficult at best since you'd need an anechoic chamber to prove it.
Why would an anechoic chamber be required? The proper way to measure the noise and distortion of the system before the drivers is an audio analyzer. Would you measure an amplifier though a speaker in an anechoic chamber?
The point of the 15khz tone is to see if the amp struggles with those frequencies. As most amps have a much harder time as the frequency climbs above 1khz. And there’s meaningful content in music above 1khz.
Most audio specs aren’t to prove how good the gear handles music. They’re simply for marketing purposes. And when the consumer doesn’t understand what actually matters, 1khz is enough to get the job done. ASR is a great example. The quality chart that everyone buys gear based on is all of a 1khz THD+N spec. So Amir's partners (Topping for example), just need to design gear that maximizes that spec (sound quality with music irrelevant), and the commissions come rolling in from the frenzy of sales.
Because performance within the audible band is what audiophiles care about. But some folks must only listen to music where all the tones are at 1khz. So this test would be meaningless for them.
1khz is within the audible band. I’m guessing 1 khz is chosen because its harmonics are within a reasonable range. Perhaps a sweet spot. Not sure.
Some people may actually wish to listen to a 1khz tone, but there are probably other meaningful therapeutic influences in play should they wish to do so..
You may wish to listen to a 15khz tone by what you have said. A most interesting anomaly. I don't think it would be very pleasant.
"I guess if a tree falls in the forest it really doesn’t make a sound. That is, only if you don't have the ears or equipment to hear it. "
As I noted previously, there isn't much sense to respond to someone without the appropriate experience to comment on a matter (no matter what field, audio or otherwise) - e.g.
I guess if a tree falls in the forest it really doesn’t make a sound. That is, only if you don’t have the ears to hear it, or the equipment to detect it.
but that measured distortion numbers and signal to noise, etc.....have any correlation to sound?......show me. show me the test results that prove it.
Isn’t it obvious that any audio device which injects spurious noise into the input signal which is measured at the output is not true to the source? If you like distortion, that’s fine, enjoy. But it’s called "hi-fi" not "hi-di".
This GaN amp is like the old tripath class d amp of 20 years ago- output dependent on the load. It may play nicely with some speakers but not with others. You can add or change the distortion all you want, it still isn’t state of the art and a second class implementation in comparison to other class d amps available for much less money. You can't make a silk purse from a sow's ear, so they say.
To be clear, the conclusion isn’t supported by the opening statement. You don’t know anything about me
This isn’t about you. It’s about the specs of the analyzer you claim to own. Unless the manufacturer is lying. There's been some innovations in this field since 1982.
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