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Class A into Class AB

What is the goal of a designer who makes intergrated amps that have class A for x amount of watts before it goes into class AB? Are there any examples of this being implemented well? I get this feeling that it’s kind of just a marketing thing...where people think they are getting some quality class A without the very high price tag. I was particularly looking at the CODA CSiB amps where you have three choices of how much of your first watts are class A. I have since found a few other respectable brands that implement this as well. I have yet to come across anyone who has heard much of difference between AB amps and one’s that’s state "first X amount of watts..." Class A/AB. Anyone have any experience with these kind of integrated amplifiers? Just looking for a little bit of understanding as I’m trying to upgrade my amplifier.
tmac1700

Showing 3 responses by uncleang

uncleang
106 posts
 
The Threshold S550e amp from the early 90's was rated at 250 WPC.
This stasis design had optical bias circuitry and the bias was set at 100mV.
Threshold claimed that it would run up to 20% of it's rated power in class A (that's 50 watts!!)

My NAK PA-7A MKII is also a stasis design but without the optical bias circuit of the S550e of the same era.

Bias specs for the NAK is 40mV but I run it at 50mV. It draws around 200 watts at idle. It's rated at 225 WPC.

My guesstimate is that it runs in Class A for the first 10-12 watts.
uncleang
106 posts
 
Why don't you ask NP on diyAudio.
uncleang
106 posts
 
@itsjustme...   was not clear what your point was....

The point is the name of the thread is...... Class A into Class AB

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