Chiho, Whether you hear differences or not, or whether the differences are large or small (to you) depends mainly on what you are trying to accomplish by changing amps and how experienced a listener you are. If you have no specific goals and only want to make your system sounds 'better' then I think Narrod's comments may be appropriate. But don't think that the differences are not there or that they are not important to many others. They can be small to Narrod perhaps but they will be to many others what floats of sinks their boat.
Not to be rude, but I would suggest that you take time out to re-evalute exactly what you are trying to accomplish apart from assembling competent components.
Not to be rude, but I would suggest that you take time out to re-evalute exactly what you are trying to accomplish apart from assembling competent components.