CLASS A POWER RATINGS


In well designed SS class A power amps I was told that although power could increase to double in class AB mode from speaker demands of  8 ohms to 4 ohms, class A suffered to be cut in half.

For example a class A denominated amp rated at 50 watts class A into 8 ohms would double to 100 watts class AB  into a 4 ohm load but only have 25 watts of class A power before switching to class AB.

But I've noticed of late claims of manufacturers stating their amps double their class A power as impedance demands are halved.

So is the explanation that technology has advanced ?

rost

Audiophile know thyself and pick the distortion you ( ear - brain ) LIKE.

Copyright Reserved, 1978

Another 'Class A' amp that uses the iBias is the Westminster Labs. Similar to the KRELL XD that I said is 'Class A'. I have a CODA #16 amp that is Class AB and runs the first 100 watts in Class A. The 'pure Class A' KRELL XD is very similar sonically. A bit smoother sounding. 

WestminsterLab

I hope to hear the uber new KRELL KSA i400 which on spec is incredible.

@charles1dad .. but class B operation is push/pull, not? Does not push/pull imply switching in between?

@sngreen 

No. Class “B” and push-pull aren’t synonymous. @atmasphere has given a clear (At least to me) example/explanation. His OTL amplifiers and the Mark Levinson mentioned earlier are examples of pure class A push-pull topologies. There’re others as well.

Charles

but class B operation is push/pull, not?

@sngreen  Class B only means that the amplifier is conducting for half of the waveform. You can build a single-ended amplifier that is class B (not that you would want to listen to it).

IOW Its not an amplifier, its a class of operation. You can make single-ended class D amplifiers too.