Different preamps will normally sound different to various extents. I’d expect a “quality” pre-amp to make a difference if replacing one of low quality for sure.
I once replaced a Carver preamp with an Audio Research pre-amp. Night and day!
Will a high quality preamp really make a difference in sound?? Also speaker cable
Will a quality preamp make my system sound better? And speaker cable...seems like everything I read people are split on this subject. My local hifi store brought up a good point; they said that the only thing between your amp and your speakers are the cable. Very good point and I'm inclined to believe it. Don't want to spend a fortune but don't want cheap cable either. Thoughts/ recommendations? Thank you in advance.