Exactly. In the past I've done lots of reading about whether amp differences are audible or not, and essentially come to the conclusion that most decent amps cannot be distinguished by listening to unclipped signals.
Here's a web page that describes listening tests with thousands of people trying to show they can hear which amp is which and none of them succeeding:
Richard Clark Amplifier Challenge FAQ
And I'm generally in agreement that the audible differences are largely below the threshold of audibility for most amps. But recently I got an oscilloscope and I've been messing around with looking at the actual signals going in and out of amplifiers. The one thing that is very clear is that different amps do very different things in clipping. Some just chop the waveform off the top, while a T amp clips on the "side/middle" (you'd have to see to understand). I see how beat up even a sine wave looks in some amps. So now although I still can't hear much if any difference, I think it quite possible that there are differences that are small enough that they can't be reliably picked out, but large enough that they can add up to something significant.
It's kind of like women; one day the one I'm with will seem better than all the others, another day worse than all the others, but it's the same woman.
This is something to feel, to listen, not to analise
to compare or to think about... conclusions will be numbers if you analise...if you feel they gonna be feelings.
Humans are moved by feelings, not by numbers.
In this particular case, even numbers and feelings are not enought.
No sound stage, or strange sound stage, or almost absent sound stage, no magic, no feelings, no deepness of sonics, no signature or character.
I have digital sound, and listening to it these last 6 years... so... six years long listening and comparing...no way to digital sound.
Food without salt, or the natural orange juice compared to the chemical orange juice.... can be even tastier (Tang), but has not the magic, the real thing on it.... something is too much or not enought...just different.
If you listen not worried with realism, or watch videos and the amplifier is reproducing sound effects..well...having not the original, real world sonics to compare, even a shot made using an effect that seems a sheet of metal hitted will be good and real as you are observing the "total scene" and not audio... under the "feeling eyes" that audiophiles use to perceive things...so.... noises from engines can be good..as engines sounds different and that engine sounds alike "that" engine...but other things are real and we perceive as a shocking thing, non natural, non real.
Audiophiles from Greece looks crazy, or mad sometimes...but they are not, that mad, in the reality.... old recordings, made using tube equipment... from sixties, are the best ones... the real high fidelity.... they will not stand for digital amplifiers anyway.
I believe you all have digital and analogic in your home and that you really know what your are talking about...seems to me some of you do not know..because the ones really knows, usually does not spend time discussing that because it is too much obvious to waste our time.
No doubts, one day, only digital will be produces...cheaper, ligthweight, smaller, efficient..... and sounds nice if you do not analise or be really "perceiving" the thing.... even food will be tastefull chemical things...well.... progress does that....i do prefere to be old and stupid to the modern things...as i do love to feel instead to think about.
http://www.youtube.com/watch?v=xs1aUws0Lrs
regards,
Carlos
to compare or to think about... conclusions will be numbers if you analise...if you feel they gonna be feelings.
Humans are moved by feelings, not by numbers.
In this particular case, even numbers and feelings are not enought.
No sound stage, or strange sound stage, or almost absent sound stage, no magic, no feelings, no deepness of sonics, no signature or character.
I have digital sound, and listening to it these last 6 years... so... six years long listening and comparing...no way to digital sound.
Food without salt, or the natural orange juice compared to the chemical orange juice.... can be even tastier (Tang), but has not the magic, the real thing on it.... something is too much or not enought...just different.
If you listen not worried with realism, or watch videos and the amplifier is reproducing sound effects..well...having not the original, real world sonics to compare, even a shot made using an effect that seems a sheet of metal hitted will be good and real as you are observing the "total scene" and not audio... under the "feeling eyes" that audiophiles use to perceive things...so.... noises from engines can be good..as engines sounds different and that engine sounds alike "that" engine...but other things are real and we perceive as a shocking thing, non natural, non real.
Audiophiles from Greece looks crazy, or mad sometimes...but they are not, that mad, in the reality.... old recordings, made using tube equipment... from sixties, are the best ones... the real high fidelity.... they will not stand for digital amplifiers anyway.
I believe you all have digital and analogic in your home and that you really know what your are talking about...seems to me some of you do not know..because the ones really knows, usually does not spend time discussing that because it is too much obvious to waste our time.
No doubts, one day, only digital will be produces...cheaper, ligthweight, smaller, efficient..... and sounds nice if you do not analise or be really "perceiving" the thing.... even food will be tastefull chemical things...well.... progress does that....i do prefere to be old and stupid to the modern things...as i do love to feel instead to think about.
http://www.youtube.com/watch?v=xs1aUws0Lrs
regards,
Carlos
Last edited:
I do own a current dumper (Quad 520) but there is no class c amp inside.
It contains one small class a amp and a large class b per channel.
Just as described by Peter Walker when he patented current dumping.
I have no idea how they do it but with the amps of theirs I got (T500, MC450, MC750) I can assure you that the data they give on the site for those is the absolute minimum performance you can expect.
Never heard anything bad about them and being (expensive) PA amps their customers do tend to notice when things do not come up to scratch.
Although Funktion One used them to demo their PA at PLASA and decided to beef up their subs after the experience.
Ferrite Sounds Nasty....
In my experience, on first inspection Class D sounds clean, clear, detailed etc, HOWEVER upon extended listening the examples I have heard (Icepower and others) end up driving me out of the room.
The problem is that the ultrasonics/rf emitted conspire to destroy the relaxing involvement that can be achieved with conventional amplifiers.
The usage of ferrite output filters destroys the audible sound.
Eric.
In my experience, on first inspection Class D sounds clean, clear, detailed etc, HOWEVER upon extended listening the examples I have heard (Icepower and others) end up driving me out of the room.
The problem is that the ultrasonics/rf emitted conspire to destroy the relaxing involvement that can be achieved with conventional amplifiers.
The usage of ferrite output filters destroys the audible sound.
Eric.
Last edited:
This is a bizarre statement. I didn't know that we poked people's eyes out, or even made them wear blindfolds. And, as far as I know, we are not yet using "enhanced interrogation" techniques in audio testing. So where is the stress? Of course, you can make the test stressful by putting time or other constraints on the test. But there is no reason not to put the listener in complete control - with the only thing unknown, is which of two or more systems is playing. Are actual blind people too stressed to hear differences? Or is the stress due to the listener facing the possibility that they don't really hear what they don't see?
Sheldon
I'll probably get tarred and feathered (at the very least) but I'm going to take a stand for the Dark Side. I have a highly modified and very professionaly implimented Ice amp (integrated). It is involving, musical and trounces an all-tube set-up next door in every departement (consisting of Audable Illusions pre. and Primaluna power) I can't prove this to you obviously but you'll just have to take my word. While I respect your experience (especially Nelson's), I have to take exception. Maybe I just got lucky or maybe no one has quite had one like mine, but I stand by what I say and I have many years and many amps under my belt. Voila.
I know his fancy explanation.
Output transistors work in class C, they start assisting when voltage on the resistor between their bases (output of class A amp) and amp load is enough to cause base current. This class A amp looks like a driver in class AB amp, but it is not, because it drives the load directly through low resistance of the resistor.
However, the patent mentioned a bridge, but a bridge is work-around for slow then opamps and power transistors.
Class B would mean no "dead zone" when signal polarity switches. Quad has it, and it is covered by class A amp. Strictly speaking, class C starts assisting class A when currents go up, while class A works all the way.
You may calculate output voltages on which class C devices start assisting class A. Is it almost zero volt? No way! 😉
Last edited:
Hello
Can you say more about the modifications you done to your Ice amp ?
Thank
Bye
Gaetan
Hi,
That's so 19th century.
In these latters days of George Dubya Shrub and Barak Obummer I think extraordinary rendition to Syria is more like it.
Hey, it's all just audio.
Some of my friends like Class D Amp's, others SACD, still others like Krell and Kharma and still others are "deep triode" with Lowthers and Type 71 Triodes.
I normally avoid listening to music on the SACD/Class D systems but one of my friends with such a system has excellent port and red wine ("For the love of God, Montresor!") but I do spend a lot of time listening to the "deep triode" stuff, often with cheap supermarket red.
But to each is own.
Ciao T
PS, I like Nelson's description of the sound of class D. It is not that it does do anything identifiably wrong, it just does not seem to do anything quite right (identifiable or not). Same for DS ADC/DAC BTB.
And life is to short for boring trophy girlfriends ("so beautiful, but oh so boring"), boring HiFi and music ("Amanda McBroom Sucks") and generic cheap Port and generic Red Wine ("can I shoot up medical alc instead please, or take the road of Saint John Mushroomhead?").
Or at least to put up with more than one of them at any given time.
That's so 19th century.
In these latters days of George Dubya Shrub and Barak Obummer I think extraordinary rendition to Syria is more like it.
Hey, it's all just audio.
Some of my friends like Class D Amp's, others SACD, still others like Krell and Kharma and still others are "deep triode" with Lowthers and Type 71 Triodes.
I normally avoid listening to music on the SACD/Class D systems but one of my friends with such a system has excellent port and red wine ("For the love of God, Montresor!") but I do spend a lot of time listening to the "deep triode" stuff, often with cheap supermarket red.
But to each is own.
Ciao T
PS, I like Nelson's description of the sound of class D. It is not that it does do anything identifiably wrong, it just does not seem to do anything quite right (identifiable or not). Same for DS ADC/DAC BTB.
And life is to short for boring trophy girlfriends ("so beautiful, but oh so boring"), boring HiFi and music ("Amanda McBroom Sucks") and generic cheap Port and generic Red Wine ("can I shoot up medical alc instead please, or take the road of Saint John Mushroomhead?").
Or at least to put up with more than one of them at any given time.
Hello Wavebourn:
"I posted recently my schematic of class AB output stage, that switches by shortening tails in complementary long tail stages, unluke that vast majority of transistor amps that starve output devices in crossover region."
Some link for this?
Thanks
"I posted recently my schematic of class AB output stage, that switches by shortening tails in complementary long tail stages, unluke that vast majority of transistor amps that starve output devices in crossover region."
Some link for this?
Thanks
"Class D amps sound much better than class AB amps because their cross-over region is low in level and short in time."
Actually, class D amps were notorious for bad crossover distortion. Crown's Balanced Current Amplifier "BCA" topology fixed this. I don't know what the other class D or T or ... designs do about this currently.
Crown Amplifier Technical Information
Actually, class D amps were notorious for bad crossover distortion. Crown's Balanced Current Amplifier "BCA" topology fixed this. I don't know what the other class D or T or ... designs do about this currently.
Crown Amplifier Technical Information
If this is what you intended to say ThorstenL, then why not say it in the first place? An inaccurate theoretical model such as the one you advanced only clouds the issues and assists the discussion not one whit. It runs the risk of being repeated in error. But then, as ever, you have no compunction about misleading readers, why would I expect any different?
w
I would be happy to do so but it was and is a one-off design, so that will not help you much. Also I am not entirely sure of all the changes (I let others do my DIY!) For what it's worth; the 125w SX2 module is the sweetest in the range apparently. I put a Vishay resistor passive pot in front, followed by a special buffer made for it by Wyred4Sound. Then all the caps were replaced with blackgates and Vishay foil "S" resistors replaced the stock ones elsewhere. That's as much as I know. Wiring is very short and there is liberal use of ERS paper. Voila
On the original subject to the thread, although switching amplifiers seem not to have made waves in the hi-fi world, they are certainly doing so in my area of live sound. The latest amplifiers claim (although I've not verified it!) to deliver 5kW from each of 4 channels in a 2U chassis - and that's on top of providing crossover, equalisation, limiting and making tea. They certainly seem to be on the verge of taking over completely from linear circuits in the world of extreme high power amplification.
The linear amplifiers that remain, generally in somewhat lower power categories, are mostly class G (switching power rails) and emply switching power supplies.
At the other end of the scale, I believe that switching amps are ubiquitous in battery powered aplications whrere power is at a premium (any you can get away without propper output filtering).
So, it appears that it is currently the efficiency gains if class D are justifying its increased complexity in applications at either end of the power spectrum.
One interesting question - in the case of hight power amplifiers particularly - is reliability. I will be interested to see if these newer, and as yet relattively unproven, amplifiers prove to be as reliable as their linear predecessors.
The linear amplifiers that remain, generally in somewhat lower power categories, are mostly class G (switching power rails) and emply switching power supplies.
At the other end of the scale, I believe that switching amps are ubiquitous in battery powered aplications whrere power is at a premium (any you can get away without propper output filtering).
So, it appears that it is currently the efficiency gains if class D are justifying its increased complexity in applications at either end of the power spectrum.
One interesting question - in the case of hight power amplifiers particularly - is reliability. I will be interested to see if these newer, and as yet relattively unproven, amplifiers prove to be as reliable as their linear predecessors.
Class D is similar to a switching power supply and those have been in high volume use for many years with great success and reliability.
This is hardly surprising (tomi), necessity being the mother of adoption.
Professional users don't have the luxury of considerations as ill defined as 'involvement'. Battery users really care about efficiency. Neither of these is true of audiophiles.
If you look on the sites dedicated to recording you will find users who still choose equipment by reading the specifications rather than licking their finger and testing the wind, you can't expect that kind of reasoned behaviour here.
w
Professional users don't have the luxury of considerations as ill defined as 'involvement'. Battery users really care about efficiency. Neither of these is true of audiophiles.
If you look on the sites dedicated to recording you will find users who still choose equipment by reading the specifications rather than licking their finger and testing the wind, you can't expect that kind of reasoned behaviour here.
w
Here is Kenpeter's drawing of this amp. Suboptimal, but uses details from his lib to sim it. Q1, D3: LTP. Similarly, the complementary one. D1, Q3: current mirror. Without D4, D5 it is class A output stage, with this diodes it is class AB one. I would use Shottkies for them today (it was designed at the end of 1970'th)
Last edited:
Class D sounds better, but why?
I have read most part of this thread, and I hope those participating have a look at some other threads on D-class amplifiers. Keywords: Tripath, UcD, 41Hz.
Simply put: D-class has achieved the stage of high end audiophile amplification. This on top of being useful for applications that require 5KW+, or, on the other end of the scale, need to be powered by two AAA's for hours on end.
The disappointing part: all that old, beautiful, expensive other equipment may be replaced by something cheaper and better.
The pleasant surprise: this brings high end sound to more places, so more people can enjoy.
The puzzling part: why does D-class sound better on most loudspeakers? I have a McKintosh, Luxman class A, Quad II, etc., and I prefer class D, full stop. It has something that has yet to be explained, that lends a transparency to music which I have not found in other amplifier technologies.
I have read most part of this thread, and I hope those participating have a look at some other threads on D-class amplifiers. Keywords: Tripath, UcD, 41Hz.
Simply put: D-class has achieved the stage of high end audiophile amplification. This on top of being useful for applications that require 5KW+, or, on the other end of the scale, need to be powered by two AAA's for hours on end.
The disappointing part: all that old, beautiful, expensive other equipment may be replaced by something cheaper and better.
The pleasant surprise: this brings high end sound to more places, so more people can enjoy.
The puzzling part: why does D-class sound better on most loudspeakers? I have a McKintosh, Luxman class A, Quad II, etc., and I prefer class D, full stop. It has something that has yet to be explained, that lends a transparency to music which I have not found in other amplifier technologies.
- Status
- Not open for further replies.