Which has greatest influence?

Thanks for all of the thoughtful answers. My setup at present
starts with a Prima Luna Pre amp, I recently added Conrad Johnson LP 705. Speakers are B&W 804s. The CJ impreoved my system greatly. Just wondered if I changed the Preamps would I get a similar boost?
Wondered too about matching preamp and amp CJ all the way. would that make a difference? I am somewhat new ro all of this and these questions pop up in the middle of the night,

In response to Newbee: You asked several questions in your post which I will try to answer: Re What I meant by 'boost' I wish I knew the vocabulary of the audiophile. It simply opened a richere, fuller sound, larger soundstage, a feeling of being closer to the real thing. I was just wondering if the changing of pre amp would open that door even wider. Sorry my finger slipped when I tried to identify my new amp. It is a Conrad Johnson LP 70S.
And I think the impedence rating is 100. Would appreciate any thoughts y0u might wish to share wirth an old duffer who just t`urned 90. Jack North1178

Thanks Newbee. No - had ny 90th in July. Tell me, when you go to matching pre amp to amp what are you matching? Are there som specifics to look for? Jacnorth1178