How important is the amp?

Over the last few year I have upgraded my phono amp (Sensor Prelude), Turntable (SAC Girati Grande) etc.

But I have never upgraded my integrated amp, a Symphonic Line La Musica. At what point do you upgrade your amplifier. I have been looking at a 2nd hand RG10 mk 4 reference or maybe a Kraftwerk.

When I fool around with cable and other items I can still hear improvements. As long as I can still hear changes in my system when I upgrade I think my amp is still fine or is that a wrong train of thought.

Mordante hi,
For what amp will sound the best for you really need to see an impedance/-phase angle graphs on them, I've looked for you and there's nothing.

Failing to get these graphs, the next best is to email the designer and ask them if they have the graphs or last option if they recommend what type amp drives them the best.
Before getting on the amp merry go round, to find what amp drives them the best yourself.

Cheers George
In the sense that an amplifier is a fundamental and necessary component to any audio system, they are important. As far as it's contribution to the quality of the sonic signature the system produces, provided it is functioning properly and is of adequate power to properly drive the speakers attached to it....not so important. I would think components' affect on sound quality ranks something like this:
Room Acoustics
Recording Quality
Source Hardware (TT, CD, Computer Configuration, etc.)
Power Amp
Wires and Cables.