Perfect voltage source

[tbewick]

How important is it for an amplifier to be a perfect voltage source? (i.e. rated power doubles with each halving of speaker ohms).

 

[MacManNM]

How important is it for an amplifier to be a perfect voltage source? (i.e. rated power doubles with each halving of speaker ohms).

Not very. The important thing about amps is THD, Dampening, and true rms output power. Depending on the circuit design, output impedance, etc the power out at different impedance will change.

 

[rschleicher]

A low output impedance (or source impedance), that is low in comparison to the speaker impedance, is somewhat important for maintaining a flat frequency response. This is usually not an issue for solid-state amps, and is mostly a concern for tube amps that are run with minimal negative feedback, or entirely without feedback. Even then it may not be distinguishable from the non-flat frequency response of the speakers and room acoustics.

An ideal voltage source would of course have a zero output impedance.