“One of the difficulties implementing
the ICE module is its hungry demands for a powerful input signal. The 700 watt
ICE module has low impedance (around 8KΩ) which, if not properly buffered, Little bit of obfuscation. A lot of Class D OEM modules have both buffered and unbuffered inputs. It is up to the manufacturer to either use the default, or build something else. This lets you do tweaky things like a tube input buffer, diamond, whatever. My point is, no end user is really ever going to feel or suffer from the low impedance inputs. Best, E |
Eric you've tried numerous threads to get this Class-D "praising thing"
on a roll, never to keep going, because of the "non acceptance" by way
too many for you to counter.
Give it up be happy with yours, that you say you can't hear any problems with it. And let those that can, and have been down that path go the way they want.
It's the other way, George. Every time anyone says they like Class D you jump in with as many posts as you can explaining why they must be wrong, but (based on zero evidence) the next big thing will surely fix it! I think an objective read of my posts, whether about Class D or other will show which of us has a point to prove, and trouble making it. Best, E |
We have achieved a major scientific breakthrough. Audiogon managed to hook this website up to 1982 and found this:
Maybe against backyard junkers.
It’s not yet, only in the bass.
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I find Brunos definitions kind of useless.
Most Class D have no Analog to Digital Conversion (ADC) stage, but do have comparators. Hence the feedback required.
The Technics on the other hand, really does have an ADC, and once calibrated, the output behavior is deterministic.
Best,
E
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Saying Class D is as good as Class A is like those hyping Digital is a
good as Vinyl. Are your ears truly that bad? Does a digital piano sound
as good as an acoustic? No. End of story. Someones feelings are hurt. NO no no. I meant to say that good Class D is better than several Class A amps. Please stop comparing it to such inferior technology better suited for cold climates and drafty hallways. |
Zero-feedback Class D would seem to be a unique twist. It would, since feedback is how the switching is controlled, without feedback, there can be no switching. The Technics model is different though. It uses digital signal processing to compensate for the speaker load, and then is a pure digital amp with no feedback ( I believe ) Best, E |
Maybe the question we really should be asking Kosst and George is this: What, exactly, are the audible effects of switching distortion in a Class D amplifier, and can you give specific examples, with speakers, that you have heard this from? Like all amps, I don't think Class D is right for every speaker, so I am open to the idea that certain speakers will perform worse than others. So, George and Kosst, ball is in your court. Please share with us your experiences. Best, E |
Also, this nonsense about caps burning up early due to the switching
technology is a lame attempt to scare people in an era where fear reigns
supreme. Good electrolytics last a long time. Enough of this fear
mongering.
In the amps or speakers? I think there's been a great deal of improvements in cap technology over the last 20-30 years. Low inductance, and low ESR electrolytics are a lot more common. |
I don’t recall the amp model, but Pass installed a pot on the front of the thing to dial in the distortion character ranging from a few hundredths % positive phase second harmonic to a few hundredths negative phase.
Pass makes the opposite argument you are making. Your argument is: I can see it has more distortion so it’s bad. Pass’ arguments are that MORE distortion is favorable. Further, he’s adding distortion which is in the audible frequency spectrum. Your claims Class-D switching noise (i.e. distortion) are in the RF frequency range. So, we are back to : Is switching distortion from Class D amps audible or meaningful? In fact, none of the claims of sonic inferiority here even point to that. The only counter points I hear are of sterile sounding, or lacking dimension or engagement. Which of these problems do you think come from switching noise and distortion? George insists that high speed is where it's at, based on no particular evidence. I mean, what exactly is high speed? What is too low? What is high enough? You have to buy into the idea that you have an audible problem to begin with. Best, E |
No one has provided a logical, technical counterpoint to kosst's argument regarding class D other than experiential vignettes.
No one has proven the measurements Kosst has alluded to are audible on the other side of a speaker. All Kosst has done is noticed 1 measurement. There are plenty of ways in which Class D is as good or better than many SS and Tube Class A, Class A/B amps. Noise and frequency response and low output impedance in the audible band among them. Why don't we count those 3 as better than Kosst's single measurement? Why do you think Stereophile uses an output filter in the first place? Because it is more meaningful that way. What makes Kosst such an authority that he can disregard it? Puhleese. |
@georgehifi
There’s a reason for it, it’s there and real, and if you can’t hear it,
fine. But please, don’t tell others they can’t, when they can, and the
measurements back them up.
George, All you do is tell others they can't be happy with Class D, and that they should be able to hear the same way you do. The measurements you are hell bent don't back up a thing. There is a gap between a number and perception which you and kosst can't seem to grasp, but most can. Best, E |
The evidence of my ears are telling me Class D must do distortion right. Go figure! Exactly. I’ve also heard megabuck class-A amplifiers around the time I got my Class D. Honestly preferred the Class D. I’ve had several audiophiles in my home and no one has ever said "Oh, wow, that hypersonic distortion is killing me, this is class D". In fact usually what happens is when they are getting ready to leave they ask "Oh, by the way, where are your amplifiers??" because they are so small and easy to miss. I’m not asking you to love my amps, but the idea that Class D are not competitive with the best Class A is nonsense. |
Go to Stereophile and look at the last 5 or 6 class D amps they’ve measured. Unless JA applies a low pass filter on the AP the output signals look horrendous. Even with the low pass filter, they all have ringing. I was just looking at the Below Canto Black and that thing isn’t horrible, but .05% of garbage distortion at 200mW!?!?!? That’s ridiculous.
- Kosst The problem is you are "looking" and not listening. We apply the low pass because the distortion analyzer’s numbers would pick out signals no human could hear, not to mention those signals could not make it past the speaker drivers. Without those low pass filters, the distortion numbers loose all meaning for our use. It’s not just enough to have a measurement, but you have to know how to apply it correctly to an application. Blindly accepting a number as true or useful is the root of all evil. I compared Parasound A23 class A/B amps to my Class D. Could not tell the difference even knowing which was which. Tell me please how much of that ultrasonic ringing I should care about. Best, E |
Which measurements, @kosst_amogan for which specific Class D amplifier?
Be specific.
Most Class D amps measure very well, if not superbly, especially compared to some megabuck Class A amplifier.
To write more, it’s not that I am dismissive of specs altogether, but rather that once amps get to a certain level of quality, the specs alone do NOT describe anything useful about the sound.
For instance, I’ve yet to see an amp with 0.01% distortion actually always sound better than another with 0.05% distortion at the same frequency and output power. In fact, below 0.1%, I doubt any amplifier sounds better or worse based on distortion alone.
So, Kost, what specifically and for which specific amplifier are you claiming a spec is significantly worse??
Best,
E
|
Sorry, but we wouldn't even be having this discussion if great class D amps had been around for ages.
Judging by the measurements I keep seeing, great class D amps still haven't arrived.
That's the first mistake. Look, I use technology a lot. A LOT! I believe in it, but I also know the limitations. It is one thing to measure distortion given our most common measures: TIM and THD+N They may tell us very little about how this is perceived or how it affects music reproduction to the human ear/brain/pleasure centers. I can critique practically ANY amplifier to death. And also, take a look at some of the most highly touted amps out there. They aren't exactly stellar spec performers. My point: Human beings perceive sound differently than pure specmanship. If you want to go "by spec alone" then you really can't make any claims at all. I'd argue that based on the literature, some Class D are excellent amps and no one can hear better. My point? Your own ears are FAR better judges of quality and pleasure. Find me a measure that compares pleasure to transistor speed and I'll be really interested, but claiming that there's X parameter that Class D amps have to overcome before you admit they are excellent is hard for me to accept. Do you know what I cannot argue against? People saying "I heard Class D amps by X manufacturer, and I did not like them because they sounded like ..." That's fine. But me? I've heard great Class A amps from highly touted makers and I preferred Class D. And here we are back to my overall thesis: Buy what you like listening to, specs and other people's opinions be damned. It's your wallet, and your time on earth that is important. No specs, no transistor speed, no class (A/B/D) matters when it comes time to spend your money. Make yourself happy. What I lack, is a belief that a specific set of technical specs can be made so much better in Class D that they would change everything. Sorry, I like what I have. Show me not the spec but the performance and I may want more. Please, buy what your ears like. Best, E |
And your old one with the lower switching frequency, will become unsellable junk save for use as a bass amp. Don't need to sell what I'm happy listening to George. Best, E |
I'm happy for manufacturers to be pushing the envelope. That's great.
All I'm saying is that the idea that the next great thing is just around the corner and it's the end of all audio is a little over hyped.
There's always a next-great thing. In the case of fast transistors, cool. Show me an audible benefit that everyone can hear before I get that hyped up about it.
Best,
E
|
I encourage everyone to listen for yourselves.
While there are lots of fun puzzles left in the world of audio technology, solving them may or may not have appreciable benefit to end listeners.
That’s something only listening for yourself can decide.
Selling you a problem you didn’t have in the first place is what drives the industry.
The trouble with the Techniques amps is that you can't attribute their sound just to 1 technology. This is a pretty remarkable amp, but there's also DSP speaker impedance correction going on. You cannot say "great amp, must be the super fast switching speeds" unless you can eliminate other variables.
Are fast transistors cool? Of course they are. But great Class D amps have been around for ages.
Yet here is George, standing outside an airport with a sign saying "Planes can't fly!"
Best,
E
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Strictly speaking, encoding is not used in Class D. There is no conversion of one type of data to another. Instead Class-D relies on feedback, and a great deal of it. It is a comparative technique.
That’s the nature of Class D and why it remains overall an analog process.
The Technics uses no feedback. It has at least 3 processing steps:
1 - Initial encoding from Analog to Digital
2 - Signal processing(alters the input signal to match the speaker behavior)
3 - PWM
Away with your nonsense, but I expect you will write four pages of barely related word salad to reply.
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FYI, Class D is NOT digital, it is analog all the way through. There are no
zeros and ones.
Class D is analog, but the output is switched, so IMHO it's arguable to say there are no zeroes and one's. There are, in the output stage. However, the control of that switching state is purely analog. There are also some amps like the latest Technics SE-R1, which are true digital amplifiers in that they convert everything from Analog to Digital, allow for phase and amplitude correction in the digital domain, and then produce an output based on a PWM output stage. |
There are "top end" amps in A, AB and D, have been for quite a while.
Not sure I understand why that would make anyone unhappy. I think it's
pretty cool, both from a vintage point of view and newer designs.
Agreed. I think a large part of this is aesthetic and manliness. Imagine in 10,000 years, if man still exists, that audio technology reduces the top end audio and multi channel systems to the size of a book. Would we still be desperate to own the latest? E |
