Pioneer A400X Amp v Pioneer A400

[bassheader]

I'm currently using a Pioneer A400X Amp.
I'm thinking of purchasing a used A400.
Would there be a noticible difference in sound?

 

[shadders]

Hi,
Possibly. It may be by an "X" amount though.

Regards,
Shadders.

 

[Al ears]

It has been suggested by some that the X is slightly more detailed although you may not hear it. Why the change?