McIntosh MC-2100 -- Aragon 2004 MKII ... upgrade?

I have a McIntosh MC-2100 amp, in VERY vintage shape (5/10), and even though I usually like the midrange and the imaging I think I would like more detail in louder complicated passages. I'm working with a strict budget here, and I read that the Aragon 2004 MKII would be a good mate with my Thiel CS 2.2 speakers. I really can't spend more than $600 used.

Here is my current setup:

Music Server (optical out) >> to
Valab DAC (diy interconnect) >> to
passive preamp (diy interconnect) >> to
McIntosh MC-2100 (diy speaker cables) >> to
Thiel 2.2

Would the Aragon be an upgrade? If not, what would you recommend for the biggest bang for my buck in my price range?

I have a Musical Fidelity A3CR (Stereophile Class A rated I believe for what its worth) currently unused that will be going up for sale soon essentially in that price range. I was going to put it into my second system but it is too big to fit into the cabinet I use there, so it has to go. Check out the info available for it here and on the internet. I think it could fit well into your setup. I used it happily until recently upgrading to a much more powerful and expensive Bel Canto amp. Email if you think you might be interested.
I had an Aragon with Appogee Centaur Minors. Not a bad match. However, IMO the match was a bit on the bright side of things, and I prefer a slightly warmer sound. The Thiel speakers I have heard are very very good, but revealing of upstream electronics. IMO-the match with Aragon 2004II could sound a bit bright and analitical in nature. I suggest you try some used McCormack amp with your Thiels. The DNA series from McCormack are wonderful. Good luck.
Hi Dusty,

I have the Aragon 3002, which is a more powerful version of your amp, and until I had the internal parts upgraded (Blackgate caps, etc.), it didn't sound that good to me. The A3CR might be a better option. You have the option of putting better parts in your amp, as I did. The Mac with some new internals might be the way to go.

I would go for the Musical Fidelity A3CR also.Your Thiels my reveal some flaws on the Aragon(a good amp)that you won't have to worry about on the more refined (in my opinion) Musical Fidelity.
I had an Aragon 2004 Mk II many years back. Had great bass control and good detail. However, I did not find it musical, engaging. I ended up with tube gear but I'm sure there are some SS amps in your price range that are more musical, warm. A friend has B&K and it sounds musical to me.