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it IS indeedreally hard to say, but I think one thing is fairly safe to say

Posted by mhardy6647 (A) on November 12, 2024 at 07:48:25

In Reply to: It's really hard to say posted by Tre' on November 11, 2024 at 19:50:40:

Class AB amplifiers are not at their best at very low output power levels. A Class A design will probably/usually sound better at reasonable listening levels on very high sensitivity loudspeakers than a "similar" (whatever that would mean, practically speaking) Class AB design. This is important for some of us ;) -- far less important for most people nowadays given modern trends in passive loudspeaker design.

A couple of notes.
As I implied above, there are subclasses of traditional Class AB operating points which will be more or less immune to crossover distortion than a "typical"/textbook Class AB1 amplifier design. In other words, it is really hard (impossible) to generalize very constructively as to an answer to Leo loves music's question. Sorry!
A push-pull amplifer can be designed to operate in Class A (both 'push' and 'pull' devices fully active and conducting/dissipating power - mostly as heat - all of the time), Class AB (intermediat bias/efficiency compared to Class A or Class B), or Class B (the 'pull' devices turned off when the 'push' devices are conducting -- the most efficient variant for an audio amplifier). A single-ended design must operate in Class A.
Tubes or transistors van be used as the active 'devices' in all cases.

Yamaha (for one) have made several integrated amplifiers cleverly designed and built to operate in either Class AB or Class A at the flip of a switch. Those amps give the fairly unique option of comparing operational topology of an amplifier with, in essence, "all else being equal", at the expense of far lower output power and much more heat produced (lower electrical efficiency) in Class A operation.

Here's an example of one: the CA-800 integrated amp from ca. 1975. Something like 45 wpc in Class AB; ca. 15 wpc in Class A.

all the best,
mrh

Edits: 11/12/24 11/12/24 11/12/24

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