atmasphere, as someone who designs amps (for many applications), I cannot agree at all with your comment w.r.t. amount of feedback and sounds profile. There are far far too many other factors at play including open-loop bandwidth, compensation network, or just to make it simple, transfer function including load to simplify to an amount of feedback to equate to a particular sound.
Your simplification suggests a marginally unstable system as opposed to an over-damped system.
Your simplification suggests a marginally unstable system as opposed to an over-damped system.