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 ?
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. 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? |
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 |
@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. |
