CLASS A AMPLIFIERS

Chuck, even single ended Class A amps are capable of respectable power out-put. The solid state single ended Class A Pass Aleph 1's power ratings: 150 Watts > 8 Ohms, 300 watts > 4 Ohms, 600 Watts > 2 Ohms. Of course these amps were expensive exceptions to the norm. The less expensive Monarchy solid state SE 100 single ended Class A power amps power rating: 100 Watts > 8 Ohms, 200 Watts > 4 Ohms. The Monarchy hybrid tube/solid state single ended Class A SE 160's power rating: 160 Watts > 8 Ohms, 320 Watts > 4 Ohms. Needles to say I can't personaly verify these quoted ratings. There does seem to be some confusion about Monarchy's most recent 250 Watt Class A/AB hybrid's power ratings.

I shouldn't have singled out Monarchy for "confusion" with re: to rated power out-put. One of Pass' amps failed to achieve rated power during a test by Stereophile.

Unsound

I agree and I didn't mean to suggest that single ended amps couldn't produce high power what I mean't, and I may be wrong here, is that they don't produce the power output of a push-pull design e.g. Pass xa versus x series amps. And yes I remember reading the Stereophile article concerning the power output of the XA200 at least I think it was the XA200 falling short of rated output.

In general, and my logic may be off here as well, I think of class A amps (SET vs. Push-Pull) like I think of tube amps (SET vs. Push-Pull). SET tube amps typically have power outputs in the range of 3-50 wpc while push-pull varieties have power outputs in the range of 50-500 wpc. Anyway sure is fun to have these discussions as I usually learn something in the process.

Chuck

Chuck, I think your right about single ended amps being less likely to produce as much power as push/pull, but, when it comes to solid state the differences aren't as great as in tube amps.......
I'd still like to know if those ss amps that are touted as being pure Class A and being capable of doubling down, maintain pure Class A operation as they double down.

Unsound,

The Krell FPB "Class A" series maintain Class A operation
from 8 ohms to 2 ohms.

They have well regulated power supplies that have the current
capacity to deliver the current that low load impedances
require.

Given the well regulated nature of the power supply [i.e.
the ability to put out the rated voltage independent of load ]
and the current capacity to back it up - that's WHY a
Class A Krell will double down.

Dr. Gregory Greenman
Physicist