Adcom GFA 5500 v B&K ST 1400 II v Rotel 990

Hui, I picked up a Adcom GFA 5500 MOSFET amp . I am using a GTP 565 preamp with it. At this moment Vandersteen 2CEs with AP Oval 9s and Solo crystal ovals. Marantz SACD 7001 is the main source.

Would there be any reason to switch to a B%K ST 1400 series II? I have had the B&k ST 140 vesions and thought they were musical but a little dark and the speakers are different so hard to be sure. My take on the Rotel 990 ve the Adcom is the Rotel is alittle grainy or sandy sounding and the stage is not as large and sounds more congested then the Adcom. Not sure a Rotel 990 or 995 preamop would help as I have had them and feel that they are somewhat veiled and dark (much to my surprise) This has been pointed out in some reviews. Maybe it is just between the Adcom and B&K?? FYI I think the 5500 has a larger stage then the 555II I borrowed and is not quite as mechanical and dry.
Thoughts before I do something stupid.
I've owned the Adcom amps over the years, GFA 555, GFA 555II.
I liked the GFA 5500 the best!
Upgrade your preamp to a GFP-750 or Primare P-30, (both under $1K used), and you'll be happy, -IMO.
Good advice, the GFP-750 is a major upgrade.
I have to agree. Looking at the preamp is a much better idea. I also agree that a passive like the GFP-750 is an excellent low cost solution. If you can't get a really good active line stage, I say don't get one at all.

The only thing I would add is that you would probably get better results using 2 sets of speaker cables that are exactly the same. I've done quite a bit of experimenting and was never able to get a pair of Vandersteen's to sound right with anything other that 2 runs of the same cable. Even if you drop down to a less expensive cable, it should still sound better.
Not sure how the adcom compares to the amps you mentioned, never owned them. I did compare my gfa-5500 to parasound hca-1500 and I prefer the parasound amps. Much much better low end, tighter, more precise, deeper etc. The top end was also nicely improved...... Speakers I run are the old infinity kappa 8.1's
One reason I am not sure about this is the 5500 does not sound like your typical Adcom. it is MOSFET On the other side of the coin the B&K is a 1400 series II . Does that mean it still sounds like a 140??

As for preamps the 750 is out of my range and now you have to add a phono section or headphone amp ( I think) I have a 565 and would really like remote. Is going to a 710 or a 715 going back wards?
Going to a GFP-715 is a lateral move. Here is a user review that compares 565 to 715...

You haven't said what your budget is and what you are looking to gain with an upgrade.