To me it's always the loudspeakers which have the very most impact on what you're hearing, but there are limits as to how much better you can get. And with loudspeakers there's always the issue with how compatible they are with your room, where they can sit in the room, what kind of amp you're running and what your budget is. All of this factors in.
Preamps aren't concerned with room size, what power amp you're running (for the most part), etc.
You mention having a $5000 budget. In that case, I heartily recommend you seriously consider the Linkwitz LX521 system. Most do them as a DIY project, which is where you get the very best price, but there are guys out there who will sell you a fully built, plug 'n play setup, at considerably more money than your $5000. But within your budget, you can build an LX521 set, WITH AMPLIFICATION, and have $1000 left over. The LX521 is not surpassed by anything at any price. Build a pair of these things and you'll never buy another loudspeaker, ever.
The other option is that for about $3000, when you can find them and they do pop up here there, is a used set of Linkwitz Orions, which are the LX521 predecessor. That's what I run and I have yet to have a visitor come to hear them and not leave without envy. And when you buy 'em used, they're already built...
Preamps aren't concerned with room size, what power amp you're running (for the most part), etc.
You mention having a $5000 budget. In that case, I heartily recommend you seriously consider the Linkwitz LX521 system. Most do them as a DIY project, which is where you get the very best price, but there are guys out there who will sell you a fully built, plug 'n play setup, at considerably more money than your $5000. But within your budget, you can build an LX521 set, WITH AMPLIFICATION, and have $1000 left over. The LX521 is not surpassed by anything at any price. Build a pair of these things and you'll never buy another loudspeaker, ever.
The other option is that for about $3000, when you can find them and they do pop up here there, is a used set of Linkwitz Orions, which are the LX521 predecessor. That's what I run and I have yet to have a visitor come to hear them and not leave without envy. And when you buy 'em used, they're already built...