2. amps-preamps
  3. 162022-139155

When does my class Atoll IN200 A/B integrated switch from class A to class B?

I have an Atoll IN200 integrated amp (earlier version of this: https://www.atoll-electronique.com/en/products/integrated/integrated-in200sig/)

Having read a lot of praise about class A power, I’m wondering how to tell from specs when my integrated likely needs to switch from class A to class B?

The reason I’m curious is that I’m still wondering how my speakers might sound with a pure class A amplifier (such as Pass, etc.) but perhaps the integrated I have is already demonstrating much of that if there is a long enough delivery of class A power from it already? My speakers are 8 ohms, 87 db sensitivity, standmounts.

I apologize if this question is too simple; I hope I’ve posed it clearly.

P.S. This is not about dissatisfaction with my integrated or other gear (I have tubes, too). It's really just part of a longer term attempt to understand how different power sources change the character of a system, particularly the speakers.
hilde45

Showing 3 responses by twoleftears

twoleftears's avatar
twoleftears
5,320 posts
 
Yes.  10W sounds exactly right for the '400 model.

Coda is an interesting company in that it has models with different flavors, i.e. with different levels of class A operation.  Unfortunately this isn't a switch on the face plate; you choose which version when ordering.
twoleftears's avatar
twoleftears
5,320 posts
 
https://positive-feedback.com/audio-discourse/leaving-class-a-2019-redux-a-biased-opinion-from-nelson-pass/
Unless the manufacturer specifies the transition point or some magazine has done the measurements, I don't think there's any way of knowing exactly.  Manufacturers tend to boast about amps that run well into A before leaving and going into AB. So if a manufacturer doesn't specify, it's probably very low.
Still, the difference in sound that you might hear between your Atoll and a Pass or a Sugden isn't all attributable to class AB vs class A operation.
twoleftears's avatar
twoleftears
5,320 posts
 
That seems extraordinarily high for an integrated that's rated up to 120W into 8ohms and which has no external heatsinking.  In fact, I find it hard to believe.

When I think of high transition point amps I always think of Coda.  Take a look at the specs--and the build--of a few of them.
More to discover