Revolution in A-B Class Amplifiers

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#81
tinitus said:
don't know, but sounds strange to call it classAB if it puts out 400watt in 3ohm with just two output transisters
(maybe it would be more like pure classB ?)

as I understand it, it originates from the already existing commercial classAB
and the very complicated input/driver stage is being replaced by small input trafo, to make it more DIY friendly
sure, Nelson does that too, with a probably completely different classA design
but I don't see why that automaticly eliminates any other use of input trafo
many tube amps have used input trafo long before any other
Nelson's F6 is most likely very different
Click to expand...

Class A/D does sound strange. It may imply that it has the attributes of both. The brute power output of Class D, and the "sweetness" of Class A. The title of the patent application in previous post, talks about a Class AB amp driving the loudspeaker up to a preset power level and then a Class D amp takes over and pushes much higher power levels. In this case it seems that both amps operate independently, and a smart circuit determines which amp to engage based on preset criteria. The Class AB amp in said patent application can as well be Class A instead of Class AB, and this Class A amp can be one of many to include diy FW amps. But then an FW Class A amp inevitably has large heat sinks and robust linear power supplies instead of the modules which AP2 talked about and may be small by comparison.
 
#82
If the input signal is required to be ''floating'' and not ref'd to ground, is it possible that means the output push-pull power supplies are not tied to a common power ground? Bridge mode AB with variable, differential supplies? Digitally controlled supplies?
 
#87
hi,
I do not want this thread turns into quiz. maybe I should wait a bit before launching a title like this, certainly impressive but I can assure you that I have no return of convenience, as the amount of visits.
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only a few have made ​​intelligent questions, such as shanx. my answer is yes, I control dv / dt according to the current (load) by transient course.
The amplifier remains in the range of pure class A (class d no addition) I just found a way to make it free from hysteresis, needless to current, and free to modulate quickly without adding thd.
In a very very fast built-in amplifier (currently), the driver section consumes 8 to 30W, depending on performances that we want to achieve high slew rate....why?
 
#88
Example , why? we turn in A class range (high bias of course, but what we have changed the end? what is the relationship that changes the harmonic structure ?
I can get this without high bias ?

etc. .. etc. , we could go on for much longer. ( perhaps it is the best method of study hehe !
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Some amplifiers have a characteristic sound, it certainly can pleasure, plays on the psychology of the listener, personal taste, etc. ... I agree.
But if we look at the amp, from a purely instrumental or mathematical, we find that this sound is dictated by the particular modification harmonic.
primarily responsible for these micro distortions that ride the signal, is the non-linearity. This change some segments of the signal (right has a relationship with the amplitude)
contribute to the non-linearity segment, not only the semiconductor junctions, but also the passive components, the first place the capacitors.
 
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#90
tinitus said:
yes, that would have been preferred

this is not a good way
Click to expand...
AP2 suggested more info in 6-7 days; which will be welcome. My guess is that AP2 was highly excited about his invention [like any scientist] that he wanted to shout it out to the diyAudio world who [we DIYers] are always hungry for new knowledge and technology. Patents and business got in the way of swiftly releasing his info. This thread is a heads up on his forthcoming brainchild amp.
 
#91
AP2 said:
hi,
The amplifier remains in the range of pure class A (class d no addition) I just found a way to make it free from hysteresis, needless to current, and free to modulate quickly without adding thd.
Click to expand...

AP2 said:
Example , why? we turn in A class range (high bias of course, but what we have changed the end? what is the relationship that changes the harmonic structure ?
I can get this without high bias ?
Click to expand...

You have even redefined "class A" so what else have you redefined after your taste.. Are a single word used correct or in the right place?

This scenario reminds me of a well dressed and proper looking person that in the ´80´s several times dropped into my design center...
He spoke of an invention of an new technology amplifier he was soon to release. After his second visit I knew he was a fraud.
 
#93
In a very very fast built-in amplifier (currently), the driver section consumes 8 to 30W, depending on performances that we want to achieve high slew rate....why?
Click to expand...
For mosfet that rate of charge transfer to/from gate needs to be faster for higher operating points/larger devices and means (typically) more current required if you want to modulate with high slew rate. In digital switching less of a problem (but still a factor) but more so with ''linear'' dissipation.
I promise not to ask any more leading questions...it is up to you when you want to release your design for the forum.
 
#99
Not interested.. I only interested to some brilliant sounded amp.
The problem in most amplifier is not transient. Sorry for straight comment but I am designing amplifier for 13years for hobby, even my main job is designing industrial instruments.

Total efficiency, may be you mean is Maximum efficiency. Max eff in class AB is useless, it vary very different while using normal playing efficiency with various biasing.
 
#100
There is an amp that was designed many years back now, and patented by a well known person that utilized a 300B *and* a digital (switching solid state thingie) wherein the 300B is in class A and controls the transfer function. Very clever it was. Trying to recall his name, I ought to know it as he has done a lot of interesting things... somehow this sounds like it will end up being a bit similar?

Waiting with bated breath, and turning blue in the process...

...I'll stop back in a few weeks and see what came out.

_-_-
 
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