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

Why not just buy a Sugden amp and end it. You will no longer have a yearning for anything else....read up on Sugden, they were the first with SS Class A in 1967. No BS class A that transitions to class A/B....I had not even heard of Sugden, but a few years ago. My curiosity peaked, and I broke down and bought one. It set me back a decent penny

..but man I’m glad I did it.....A21SE Signature...once that was in place, I again broke down and purchased my Tannoy Speakers, now I’m in the poor house lol. I’ll tell you what, it’s one heck of a combo. You would not believe how good only 30 watts per channel can sound (40 watts into 4 ohm). I’m pretty much set for life, as I’m old.

The best class A amps have doubled their wattage into 4 ohms for at least 40 years.

I have a pair of mark levinson  33h mono blocks each one weighs over two hundred pounds they double every time the impedance  is halved and they are stable  to 1/2 an ohm. They stay class a all the time and when they were tested the output power was limited  by the input power. Each one the minimum  power requirements  are two dedicated  20 amp circuits.  They do not switch  to an ab amplifier  and there power doubles not halves as the impedance  is halved. 

@rost Wrote:

CLASS A POWER RATINGS

My understanding is a class A /AB amplifier will have a switch to differentiate between the two classes. The switch changes the amplifier's quiescent current. My amplifiers have a switch on the front panel in class A for 30 watts output, @ 8 Ohms the quiescent current is 250 watts and in class AB for 200 watts output, @ 8 Ohms the quiescent current is 80 watts. In my audio system my amps are always in class A mode. I hope that answered the OP question. 😎

Mike