pure Class A real?

merhaba, ax 6500 ve ax6300 olmak üzere iki adet 4 ve 2 kanallı modelim var, class aa scam mı yoksa gerçekten class a mı? yoksa sınıfta biraz watt olarak mı çalışıyor siz değerli forum üyelerinden bilgilerini rica ediyorum.
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If JVC says it is class A it will probably be that. But they don't specify how many watts are class A. 1, 2, 5, 10, maybe 20?
The AX6300 gives you 4 times 50W / 4ohm
The AX6500 4 times 70W / 4ohm

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Hugo
 

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It doesn't say that the output stage is the Class A circuit. Some amps have a class A preamp stage. Some simply use pull-up resistors to the op-amp supply voltage (connected to the op-amp output) to force the op-amp into passing current at all times which they consider to be class A operation.

In some amps, they can use tracking power supplies to make it run efficiently at full class A but I don't see that there.

The single 2w emitter resistor on each output transistors doesn't seem like a pure class A output section.

If it has more than about ±15v of rail voltage, it's not likely to be a pure class A output stage with that small heatsink.

As was stated above, it may be class A (output stage) up to a watt or two but that's more likely a high-biased class AB.
 
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frugal-phile™
Joined 2001
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As i understand that it is possible to reduce the power consumption of a "Class A" amp with sliding something (bias? rails?).

It suggests to me complexity that a basic Class A amplifier does not have to concern itself with. So less room for chaos.

There should be a lot of discussion on the subject here already.

dave
 
merhaba, ax 6500 ve ax6300 olmak üzere iki adet 4 ve 2 kanallı modelim var, class aa scam mı yoksa gerçekten class a mı? yoksa sınıfta biraz watt olarak mı çalışıyor siz değerli forum üyelerinden bilgilerini rica ediyorum.
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hello, I have two 4 and 2 channel models, ax 6500 and ax6300, is it class a scam or is it really class a? Or does it work as a bias watt in the classroom, I ask you valuable forum members for their information.
 
I wanted to know how HE defined class A. Class AB is class A up to a certain level. Full, normal, class A dissipates a LOT of heat if the rail voltage is fixed.

There is no real advantage to class A. Douglas Self got VERY good, very low distortion results from class B.

Some people hear garbage on the internet and take it for granted/gospel. That's why I wanted to know his definition/reasoning behind the question about class A.
 
How do YOU define class A?

Why do you want class A?
Very pertinent questions. The answer to the first would determine if sliding bias can or cannot qualify as class A.

The second is easier to answer. In most implementations it has a specific, hard to duplicate sonic flavour. It also allows to design very low distortion amplifiers without resorting to loop NFB.
 
How do YOU define class A?
I use this one
The type of “Class” or classification that an amplifier is given really depends upon the conduction angle, the portion of the 360o of the input waveform cycle, in which the transistor is conducting. In the Class A amplifier the conduction angle is a full 360o or 100% of the input signal while in other amplifier classes the transistor conducts during a lesser conduction angle.

It doesn't really matter how this is achieved.

Those that use them tend to look at the power needed at listening distances. For instance loudspeaker
spl 87db. 10w amp the 5m spl is ~85db, 15w would push it up to ~90db 15w per channel stereo was high power in the "olden days". ;) More wide spread use of "hifi" and transistors pushed that up pretty quickly starting in say the mid 60's.