In my opinion, just about all your equipment could be upgraded for a better soundstage.
The Adcom is a great amp, but if it hasn't been serviced lately, I would look into it. I think Musical Design does upgrades for Adcom and they weren't very expensive. (In fact, I just sold my 555. I found it to compare favorably to my McCormack DNA-1-which is 20 years younger).
The NAD preamp would be my first choice to upgrade, though. If you can provide a budget, maybe we can give some suggestions.
Lastly, the Dual, though a renown workhorse, could either be upgraded or at the least, have a new cartridge installed. Since I have gone to the digital side, I can't give any recommendations.
The Vandies are probably the best part of your system and will sound better with each improvement you make.
HTH
Bob
The Adcom is a great amp, but if it hasn't been serviced lately, I would look into it. I think Musical Design does upgrades for Adcom and they weren't very expensive. (In fact, I just sold my 555. I found it to compare favorably to my McCormack DNA-1-which is 20 years younger).
The NAD preamp would be my first choice to upgrade, though. If you can provide a budget, maybe we can give some suggestions.
Lastly, the Dual, though a renown workhorse, could either be upgraded or at the least, have a new cartridge installed. Since I have gone to the digital side, I can't give any recommendations.
The Vandies are probably the best part of your system and will sound better with each improvement you make.
HTH
Bob