The C64/SID can do much better sample replay then the CPC/AY, just have a listen and look at this:
https://www.youtube.com/watch?v=p6LYrQk5I7s
There's even a description in the description describing how it was done. Channel 3 plays multiple samples
at once, that's effin impressive.
The SID was designed and intended to be a musical instrument by Bob Yannes.
The AY was intended as a beeper for slot machines by GI.