It was 7Pm when i left "office" and drove home with my wife, from hard days work.. No, it wasn't that hard but a long day.
Switched on the Class A, Antenne Bayern still plays it's song and it sounds so good.
Even it sucks energy like crazy, but if one can say A, then he must be willing to say B= Bezahlen (for English PAY)as well.
In these Pics above actually I tried to show some people how we can get CLASS A Quality Sound with less HEAT WASTE, and it was not me who had the Idea how it could be installed easy. Even, it may cost some more thinking, to make it happen. but it can be done, and I'm going to try it..
And the Answer which RobertS61 is searching for, is hidden in there. And its true More BIAS CURRENT less distortion this is more than true, at least for single end Class A.
No, it don't matter what brand you use, it's for most the same.
In the pictures you can see the one and same amplifier burning either only a lot of heat and little output or less heat and more, and now it comes, with the same Quality Sound the equal amount of Output Power. All what one has to do, is testing a bit forth and back.
Soon, the next circuit will be drawn, and I will add this function, that if the amp is switched on but no MUSIC IS PLAYED it will draw almost no current.
Just the Current of the running free Transformers.
So, no heat is generated, it will not be zero, no but nearly.
The tendency of a good class a is heating up with a few minutes. so this is the only may draw back that one then has to listen to "somewhat less quality sound" till the Class A is hot. BTW only a HOT CLASS A sounds good.. 70Celsius is about right.. Starting at 50 ending at 75.
This is my goal.. not to become 0 but to become 1. Always the same decent sound.
Thanks guys you are great.
Quarter to midnight here in Swiss..
IF there wasnt such disdain for digital, it could be used to advantage, by delaying the music signal within the amp - while creating an envelope signal AHEAD in time before the music, to control the bias. This way the bias anticipates what's coming in the music and increases the bias prior to that upcoming large transient.
I've always wondered people work so hard on DACs, then work so hard on AMPs, as if there MUST be a length of wires between the two - that's just "how its done". Why not work so hard on an AMP and DAC intertwined, where tricks like above can be implemented?
I guess such a thing would be out of the realm of analog source audiophiles. Who'd want to chop to digital just to get the dynamic anticipation bias?
I've always wondered people work so hard on DACs, then work so hard on AMPs, as if there MUST be a length of wires between the two - that's just "how its done". Why not work so hard on an AMP and DAC intertwined, where tricks like above can be implemented?
I guess such a thing would be out of the realm of analog source audiophiles. Who'd want to chop to digital just to get the dynamic anticipation bias?
I absolute LOVE the power cable.... is that the original cable that comes with the amp? Captive?
Attachments
That's not the case as Nelson Pass argues in his article 'Leaving Class A'
He says:
"What we see clearly is that higher bias lowers the distortion at all power levels, and that the distortion is inversely proportional to the bias current."
........
"So far we have only talked about push-pull Class A bias. Do the effects of high bias also apply to single-ended Class A bias? Yes, but in a slightly different way."
All the XA and XS PassLabs amplifiers are PushPull.
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Certainly not. Must be Robert's favourite PC. Plugged into his favourite cryogenically treated power strip 🙂
Hi
No, there is no disdain for digital. Put it another way around.
Example, a Class D is like an APPLE Watch, all of plastic least expensive one can find and Electronics where not much craftsmanship is asked to be produced. and of course not produced in the USA as far I know. FOX CON I think.
A Class A is the flagship of Amplifiers. like a ROLEX..
Made out of selected only best steel hand crafted which really still shows craftsmanship.
We can take what MANUAL OR AUTOMATIC Watch ever from any country and compare, the comparison stays the same to a digital Watch,
If we take cars then it's like a Rolls Royce compared to whatever - trying not to get anyone upset here. or a Cinque Cento...(FIAT 500) A very good car though.
Both run bot using Gasoline, but in the Rolls you have more Quality and Comfort and of course it's more expensive..
Both watches Rolex and Apple watches, displaying the time, but the Rolex displays only time and Date, because it's a watch, where an Apple watch is just a electronic device which displays not only a watch, many other functions, which is NO MORE A WATCH. in common sense, but a minicomputer you wear on your wrist. I don't need such things.
1980 there was an electronic chip on the market * can't remember the name or the brand* where one could create and perfect 1st and 2nd Order Butter-worth Network filter.
One small IC..Dual in line 8Pins 5-0-5 Volts up to 15 -0 -15 Volts two Caps, two resistors and one would have a active Butter-worth network. It was one of the first DSP Networks, remember that because I made several circuits with that one,,
It was based DIGITAL. And at the end, I was not able to get the DIGITAL Modulation out of the ANALOG Circuit anymore.. This was the day when I decided, not to mix Digital and Analogue together.
I know that is 40 years back, and today's devices will be much better than then.. but one time burned it still hurts today.
And Class D is using a PWM and a PWM is my eyes, is at least what the part of that P and W section means, digital.
So please forgive me, I think different ..But I think I still think reasonable..
Have a nice Sunday. What a day here in Swiss, the cold has left, Sunshine is bright, wow..
all here to enjoy
Chris
No, there is no disdain for digital. Put it another way around.
Example, a Class D is like an APPLE Watch, all of plastic least expensive one can find and Electronics where not much craftsmanship is asked to be produced. and of course not produced in the USA as far I know. FOX CON I think.
A Class A is the flagship of Amplifiers. like a ROLEX..
Made out of selected only best steel hand crafted which really still shows craftsmanship.
We can take what MANUAL OR AUTOMATIC Watch ever from any country and compare, the comparison stays the same to a digital Watch,
If we take cars then it's like a Rolls Royce compared to whatever - trying not to get anyone upset here. or a Cinque Cento...(FIAT 500) A very good car though.
Both run bot using Gasoline, but in the Rolls you have more Quality and Comfort and of course it's more expensive..
Both watches Rolex and Apple watches, displaying the time, but the Rolex displays only time and Date, because it's a watch, where an Apple watch is just a electronic device which displays not only a watch, many other functions, which is NO MORE A WATCH. in common sense, but a minicomputer you wear on your wrist. I don't need such things.
1980 there was an electronic chip on the market * can't remember the name or the brand* where one could create and perfect 1st and 2nd Order Butter-worth Network filter.
One small IC..Dual in line 8Pins 5-0-5 Volts up to 15 -0 -15 Volts two Caps, two resistors and one would have a active Butter-worth network. It was one of the first DSP Networks, remember that because I made several circuits with that one,,
It was based DIGITAL. And at the end, I was not able to get the DIGITAL Modulation out of the ANALOG Circuit anymore.. This was the day when I decided, not to mix Digital and Analogue together.
I know that is 40 years back, and today's devices will be much better than then.. but one time burned it still hurts today.
And Class D is using a PWM and a PWM is my eyes, is at least what the part of that P and W section means, digital.
So please forgive me, I think different ..But I think I still think reasonable..
Have a nice Sunday. What a day here in Swiss, the cold has left, Sunshine is bright, wow..
all here to enjoy
Chris
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Even 40 yrs ago your understanding of digital vs analog was definitely wrong. It is never too late to learn🙂
I can see how you might think that, but, consider storage, DSD comes close and is digital.
My Post was actually an answer to This:
Class A in itself benificial?
But for you I have this, this is the German Version if it is to complicated for you in English
Unterschied zwischen analog und digital? – Einfach erklart
Yes it's never to late to learn.. I think this should fit your understanding of DIGITAL.
Take your time to read, there are more complex versions, but I think this one is sure the best .
Here an Excerpt for you in ENGLISH
" PWM is a way of digitally encoding analog signal levels. ...
The PWM signal is still digital because, at any given instant of time, the full DC supply is either fully on or fully off. The voltage or current source is supplied to the analog load by means of a repeating series of on and off pulses."
Do think that you understand this?
Class A in itself benificial?
But for you I have this, this is the German Version if it is to complicated for you in English
Unterschied zwischen analog und digital? – Einfach erklart
Yes it's never to late to learn.. I think this should fit your understanding of DIGITAL.
Take your time to read, there are more complex versions, but I think this one is sure the best .
Here an Excerpt for you in ENGLISH
" PWM is a way of digitally encoding analog signal levels. ...
The PWM signal is still digital because, at any given instant of time, the full DC supply is either fully on or fully off. The voltage or current source is supplied to the analog load by means of a repeating series of on and off pulses."
Do think that you understand this?
Encoding and modulation are completely different things.
FM uses almost the exact same principle and no one ever has claimed it was digital radio (which also existed, for a quite a while co-existed with FM, and was a completely separate thing).
Edit:
I looked at that article and it is completely wrong, even though I don't know any German. Digital has only two levels, high and low. The image tries to show a signal that goes below zero and has multiple levels. That is neither a PWM signal nor a digital audio signal. It is a sine wave with a square wave superimposed on it.
Look at datasheets and knowledge bases of some manufacturers, and let's keep this discussion focused on Class A amplifiers, we've gone quite far on the wrong path.
FM uses almost the exact same principle and no one ever has claimed it was digital radio (which also existed, for a quite a while co-existed with FM, and was a completely separate thing).
Edit:
I looked at that article and it is completely wrong, even though I don't know any German. Digital has only two levels, high and low. The image tries to show a signal that goes below zero and has multiple levels. That is neither a PWM signal nor a digital audio signal. It is a sine wave with a square wave superimposed on it.
Look at datasheets and knowledge bases of some manufacturers, and let's keep this discussion focused on Class A amplifiers, we've gone quite far on the wrong path.
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@scottjoplin
You see, I do not have anything against DIGITAL, but then we need to call the kid by it's name..
Otherwise I wouldn't listen to CD's, what I very rarely do.
Again, for me everybody is free to use whatever he or she likes, it's not my decision. But if these who are using Class D which contains and are based on a PWM, then there, these people also should accept, that the waveform has been changed by the PWM.
Switching adapters for Laptops and all which have an external PSU, based or which use PWM, working on almost the same concept as CLASS D. Difference is that these output a VDC.
As soon we use a Square Wave with a fixed amplitude - 0, 1 - to control then it's digital and not PURE Analogue anymore.
So easy. It's not a problem for me. I can live with that... .
That's all
I have plenty of examples if there is need of.
You see, I do not have anything against DIGITAL, but then we need to call the kid by it's name..
Otherwise I wouldn't listen to CD's, what I very rarely do.
Again, for me everybody is free to use whatever he or she likes, it's not my decision. But if these who are using Class D which contains and are based on a PWM, then there, these people also should accept, that the waveform has been changed by the PWM.
Switching adapters for Laptops and all which have an external PSU, based or which use PWM, working on almost the same concept as CLASS D. Difference is that these output a VDC.
As soon we use a Square Wave with a fixed amplitude - 0, 1 - to control then it's digital and not PURE Analogue anymore.
So easy. It's not a problem for me. I can live with that... .
That's all
I have plenty of examples if there is need of.
Yes, Whatever you say..
I'm tired..
We have a different understanding
OK I see then we call CLASS D from now on SWITCHING AMPLIFIER. if this makes you guys happy, but still it is no more ANALOGUE. and only there is the point.
OK, Listen everybody I just found one of theses things where even Wikipedia the English and the German Site are in disagreement about Class D.
Sorry, but this ridiculous..
For them who read and speak both, no problems, for the other who speak read only one of both language, translate the one you don't know..
I just post the links.. Read also the Terminology part of the English site. and Please read that part well. the German one, it's clear from the first part.
English first: Class-D amplifier - Wikipedia
Andnow the answer will be: we told you.. yeah that you did and if you read all then you finally can follow what I mean. On both sites they admit, that class d is also English (Perhaps Digital) and on the German Site, ( does amplify Digital with the PWM)
Gents read by your self, and all of you who then are not satisfied are free to Edit Wikipedia.
This was my last post on this subject.
Thanks you all was a informative discussion.
Just FYI, I haven't read that before, just a few minutes ago, and all of you are right, and me too.
I'm tired..
We have a different understanding
OK I see then we call CLASS D from now on SWITCHING AMPLIFIER. if this makes you guys happy, but still it is no more ANALOGUE. and only there is the point.
OK, Listen everybody I just found one of theses things where even Wikipedia the English and the German Site are in disagreement about Class D.
Sorry, but this ridiculous..
For them who read and speak both, no problems, for the other who speak read only one of both language, translate the one you don't know..
I just post the links.. Read also the Terminology part of the English site. and Please read that part well. the German one, it's clear from the first part.
English first: Class-D amplifier - Wikipedia
Andnow the answer will be: we told you.. yeah that you did and if you read all then you finally can follow what I mean. On both sites they admit, that class d is also English (Perhaps Digital) and on the German Site, ( does amplify Digital with the PWM)
Gents read by your self, and all of you who then are not satisfied are free to Edit Wikipedia.
This was my last post on this subject.
Thanks you all was a informative discussion.
Just FYI, I haven't read that before, just a few minutes ago, and all of you are right, and me too.
1980 DSP on a chip? Sorry, you're wrong here. The Zilog Z80 was just a few years old in 1980 and pretty much SOA. A vast chasm separates this primitive tech from a DSP.
Perhaps you enjoy labeling everything that sounds bad as "digital" 🙂
Right, the 8086 and 68k was 1979, no 8 pin DSP chip was available. What was described sounds awfully close to an op amp buffered Sallen key filter. 🙂
Come to think, Ian's Fifo is a ready made solution for anyone who wants to get an advance warning for bias control. It is even surprising no one has yet done this as it does not appear to be complicated. The fifo will need to work at a fixed sampling rate, so that the propagation delay is constant. Then you need an auxiliary low quality dac (8 bit?) which reads the input signal, integrates and adjusts the bias just before the signal demands it.