Best pre-owned 2-channel amp for under $2000??

Ok so I really could use some help directing me to a pre-owned 2 channel solid state amp to replace my Adcom GFA 555. I am open to the newest generation of Class D amps, but that would be a new purchase, most likely, and I am trying to stay in the used market for value and price purposes.

I have an Integra DHC 9.9 pre/pro, and I listen to alot of rock, blues, jazz, and female vocalists, on CD. My most recent - and largest investment by far - the Dynaudio Contour S3.4s, which I purchased new a year ago for about $5K, seem like they are asking for more and better sounding power.

I was considering the McCormack DNA-225, or the Classe CA-300, which I am sure will be a noticeable step up, but I would like some additional recommendations that more experienced audiophiles might have, based on what would pair best with my existing gear. I need to keep it under $2000 (used), and preferably closer to $1500. Thanks!

One amp that I would suggest would be the Krell KAV 250a. I have owned one of these for about 12 years and it never ceases to perform flawlessly.

I am sure you will receive many other opinions - just my two cents worth.
I would look at a Parasound A21 also. I have had one for almost a year and am not looking to change.

Check out Llano Amps. out of business, but more powerfull than a locomotive. There are two for sale here on Agon. I currently have two myslef, but those are not for sale.
say 2 outlaw M2200s $400 used have a tech mod it you,ll probly be happy you saved $$$$$$$$ Go out have dinner but know those things rock Good Luck
I would be very careful here -- your Onkyo is a great machine... Period I have an Onkyo 905 using Lexicon Monos / with B&W 800s fronts / 802s sides / htm1d center / Sony BdV5000 Blu ray / middle high end cables & power cords / Furman IT 15 Ref power conditioner-- I directly compared the Halcro Ssp200 (12k pre) and the new Lexicon HD pre to my Onkyo 905 _--- And I actually like the 905 significantly better to where I returned the other 2-- then I started a thread on Audiogon here, and most responses seemed to correlate my findings--Dave
My favorite is the Muse model 160 Mk.II for a riddiculously low $700.Hafler 9300 and 9500 transnova amps are great and less than $500.An Aragon 8008BB should set you back less than $900 and is a wonderful amp.
A lot of great suggestions. I would be partial to mono blocks. Over the years I have found regardless of brand, they work better then a single chassis unit. Always try for three, with one as a spare/compare unit. If possible look for units that can be bridged. I've been partial to Marantz for a long time. In my solid state life I presently run four MA22's, bridged for two channel effect. Integra DHC 9.9 pre/pro is a great unit, wise choice. Might want to check out Evotiva, a new guy on the block with some great values.
My favorite 'bargain' in amps is still the Proceed HPA-2, it's 95% of the Mark Levinson amps and can be had cheap, well below the $1,500 mark.
all good amps , the parasound is a killer and smooth. i have one for sale.
No mention of the McCormack DNA 1/upgraded? A solid performer.
Wyred class D will fit your budget. Plenty of power for the Dynaudios. Can be had for new in your price range. Also, check Wyred B Stock.
By the way, they sound great.
-Here is a second or third for the McCormack DNA

-Also a shout out for the Parasound Halo A21

-Odyssey Audio Stratos Stereo Extreme or Mono Extremes - last but not least

All should have what it takes to drive the Dynaudios to new heights.
I would also look at the Odyssey amps;maybe even talk to Klaus as he might have some b stock product that will save you $$$ as well and have the 20yr transferable warranty which is nice to have when you want to make another amp change.
Get a used DNA-1 or DNA-225/125, depending on power requirements (all available for well under $1500) and send it into SMC for an upgrade when you have a bit more cash. Or, just buy one that has already been upgraded (although they rarely come up for sale, for obvious reasons). The best bang for the buck I have found, and I have tried a LOT of stuff over the past few years.
There are lots of good amps out there to consider at this price range. If you can find a used Krell KSA-200S amp for just under $2000 (and you can if you're patient), that would be my recommendation.
I'd check out Emotiva. I don't own any of their products, but I've yet to see a bad review.
Thanks to all of you for your excellent responses. I will keep you posted!