push pull Vs single ended class A amp

[AndrewT]

parallel output pairs

1pair using Re=0r11 gives 0.6W of power before entering ClassB.
2pair gives 2.5W while still in the ClassA region.
3pair gives 5.5W in ClassA.
4pair gives 10W in ClassA.

But, I prefer to increase output Re as the number of parallel pairs increases bring the ClassA limit back doown.

 

[roender]

Re: parallel output pairs

2pair gives 2.5W while still in the ClassA region.
3pair gives 5.5W in ClassA.
4pair gives 10W in ClassA.

Are you shure, RMS power in 8 ohm?

 

[AndrewT]

Vre=20mV, Ire=200mA, IpkclassA=400mA, PclassA=0.4^2*8/2=0.6W
2pair runs double the current and gives four times the ClassA power.
3pair runs triple the current and gives nine times the ClassA power.

 

[roender]

Vre=20mV, Ire=200mA, IpkclassA=400mA, PclassA=0.4^2*8/2=0.6W
2pair runs double the current and gives four times the ClassA power.
3pair runs triple the current and gives nine times the ClassA power.

P=I^2*R
P=Irms*Irms*R
Irms=Ipk/sqrt(2)
P=Ipk^2*R/2
Ipk=Ipp/2

Andrew, please make the math again.

 

[AndrewT]

why?
Your formulae agree with mine and on the 0.6W we agree as well.

 

[vizion]

Is the difference between SS single ended and push pull similar to the difference between a tube single ended and pull ? Like an EL84 tube, music would sound different when used in an SET for 1.3w vs. a triode push pull model. That's for starters then you play in directly heated thoriated triodes like the 845 and such.