Question about Class A

This may not help, but it depends.  If you have efficient horn loaded speakers > 95 dB/watt-meter, you may hear a difference.  Most amps are Class A for the first five to 10 watts and switch to Class AB for higher power.  Class A is terribly inefficient, with a theoretical value of 50% conversion to power, the other 50% lost as heat.  In practice the value is 20-25%.  The amp is producing four watts of heat for every one watt of amplification power.

Here are two good technical descriptions about Class A without the audiophile voodoo

https://www.sound-au.com/class-a.htm

In short there is nothing wrong with Class AB.  Performance sound reinforcement, especially in arenas with rock concerts are running AB through PA speakers.  Try the Class A and see if you like it.  If you have the skills, they are very easy to build as there are thousands of designs in the literature.

@ronald8 , my speakers are 92db.

That is one thing that I am afraid of, that I acquire a Class A device like the Sugden but don't really hear a significant difference from what I have now (at least in my system).

Hi Jay78,

In my opinion, I don't think there is a difference in sound.  I have Klipsch La Scalas with efficiency of 101 to 104 dB.   I experimented with Schiit Aegirs (essentially Class A), Black Ice 3502s and Cary 120S Mark II.  I actually had a twinge of buyer's remorse with the Black Ice and the Aegirs and thought they did not have significant SQ improvement over my Outlaw 2200 monoblocks.  With the La Scalas, the amps are always in Class A.   It was a nice experiment:  in the long run, it probably may not be a good return on investment.  I like the Cary because it keeps my basement warm in the winter.  It is a hot beast as it runs in Class A in triode mode at 60 watts.  I would never use it in the spring or summer.  Class A amps are essentially gorgeous space heaters.

This may not help, but it depends.  If you have efficient horn loaded speakers > 95 dB/watt-meter, you may hear a difference. 

...Or not. My speakers are 98dB and we make class A amps; we also make class D amps and they sound very similar. Class A is a means of theoretically reducing open loop distortion but like all things its a matter of execution.

Just curious: I am thinking about by-amping my speakers (Quantum 2). With low/mid, mid/high and high being the high pass from 200 Hz (200/600/4000), how much power is needed? 

The idea is to use mean brute amp for thw Watkins (dual coil, dual crossover) woofer (dipping below 2 ohm), and a class A (or tube?) for the high pass.

Does someone know the percentage (for example white or pink noise) of sound energy above 200 Hz (vs below 200 Hz)? Maybe the term is 'spectral energy'? 

Less scientific: Using 200 Watt input (rated at 350 W RMS) how much power goes to low pass ( under 200 Hz, woofer) and how much to the high pass (above 200 Hz)?