CLASS A AMPLIFIERS


What are the sonic benefits of pure class A amps? Are they more "powerful"?
charlot

Showing 1 response by bombaywalla

>> 01-19-06: Aball
>> No. The sonic benefit is that the entire signal is
>> swung by a transistor (or several in parallel) instead
>> of individual halves of the signal being split up by
>> two different transistors. Since there is no "handing
>> off" of the signal to another transistor, there is
>> potentially less distortion.

I hate to say this Aball - what you have explained above is single-ended operation & not class-A operation!
it just so happens that many/all single-ended tube & s.s. amps are class-A.
For class-A operation the transistor is biased along the load line in such a way that it always has max current flowing thru it whether a music signal is input into it or not. hence the heat dissipation.
s.s class-A amps can be single-ended (Aleph series) or can be push-pull (almost every other model).
In push-pull you will have P & N type transistors but it is not necessary. For example the Plinius SA-250 has N type push & N-type pull. Slightly higher output impedance i.e. lower damping factor but all N types can be matched better.
I'm sure that you know all of this as you are trained as a EE, I think? Probably wrote your post in a hurry or while cramming for an exam the next day?
FWIW.