Now, I'm confused.

+1 1Graber and others.

I totally believe changing the preamp -- and perhaps the amp -- will give dramatic sonic advantages. Not familiar with Vandersteen speakers, but am sure people who commented above are right.

Oh, yes -- a cartridge change always offers huge possibilities for improvement in sound. What do you currently have?

What kind of budget do you have?

G

"I doubt changing the preamp will give you a wider soundstage"

Wrong!

The NAD's always sound too dark and confined to me. The GFA555 is capable of a very nice wide sound stage indeed. If I were the OP I would find a GFP565 this is a great sounding pre amp and they cost around $300 used. Sold new for $800 and it has a great phono section too.

Matt M

I too wonder about the Nad, but also how it combines with the warmish sounding Vandys.

the OP is hoping for a bigger sound stage but doesn’t say anything about his cables.  Some clean open sounding speaker cables might be just the trick.  I’d suggest Morrow Audio in this case, they have good silver content.

+1 mattmiller! Changing to an Adcom GFP565 preamp would be a beneficial upgrade! I also think that your phono cartridge (unspecified) is a limiting factor. I have found mc cartridges to be superior to mm types. I recommend a Denon 103R as a very good low-cost mc cartridge that will work well on your Dual 1019 TT.

Regarding fuses and speaker wire - neither will give you an improvement in sound quality - regardless of what the "golden ears" crowd says! I have been in this hobby for 40+ years and am appalled by the level of "magical" thinking about wire (and now fuses)! Hucksterism to entrap the gullible!