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What are the advantages to a Class A amp & what are the trade offs?

I've never had a class a amp but am considering one now. So what am I getting myself into?
128x128artemus_5
artemus_5's avatar
artemus_5 OP
1,924 posts
 
@bdp24 
I learned long ago that the low powered amps sound better to me. I've had amps for 35wpc to 250 wpc. The 35wpc sounds best in my system. Unless one is pushing an 84db speaker load, high wattage is not needed. Even then, the low power may work. The amp I am considering is 40wpc and has pushed the 84db speakers
bigkidz
3,373 posts
 

I recently built a Class A 35wpc power amp based on the First Watt design.  The Class A was much better but I also use the best parts available and point-to-point wiring.  I also recently upgraded a few Counterpoint hybrid power amps with bipolar transistors with Class A output and the difference was much better. It added more clarity, depth, dimension and faster dynamics. You have to try them out for yourself as always.  I agree with the posts above mine.


Happy Listening.

koestner
660 posts
 
Class A amps are like driving your car around with the gas pedal floored, and controlling your speed with the brakes. It is a rather inefficient method.
8th-note
401 posts
 
The class of the amp is only one criteria on which to make a buying decision. I have a mid 90's Krell KSA 300S that I dearly love but the Class A feature has its downsides. It weighs 185 lbs. and it runs so hot when I play it loud that I can't touch it. But it puts out 1200 watts at 2 ohms and it sounds gorgeous. It's a perfect match for my speakers (Mirage M3si) which are very low sensitivity (I routinely drive the amp into the highest bias level). This amp is a technology statement and there are very few new amps which can match it's performance, at least for under $50k. I am willing to live with the downsides of this amp because I admire the design philosophy and it sounds very good to me. It's kind of like owning a vintage Porsche that isn't very practical but it's just so fun to drive.

The Canary is a very different animal than the Krell but If the M70 flicks your Bic go for it but understand that the Class A feature is only one aspect of the amp.
bdp24's avatar
bdp24
9,720 posts
 

@artemus_5, I would have my 100w version modified to run in Class A, but it is powering a loudspeaker which contains magnetic-planar drivers, known for their very low sensitivity. Not as much so as Maggies, but close.

I for years used a 25w/ch Class A ss amp with my old QUADS, and that was a magical combination. If I set them up again, the amp designer alluded to in my previous post offers a real nice little tube amp, available in both Class A/B (35w/ch) and Class A (25w/ch) versions, I will definitely get the 25w version for the QUADS. The QUAD Mk.2 amp was only 15w, and that was plenty for the ESL.

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