Mccormack DNA-225 platinum

Did you ask about the impedance output?
You need that to set the M5-HP's,
And, I think you got a great deal. As far as the actual worth, that is another matter. Usually, even though it may have cost the original owner $3K+ to upgrade, the actual resale would be much less (as you have discovered). So, by buying 2nd hand, you have saved a considerable amount and gotten a super system.
Bob

@jafant  - He said it was extensively updated in the last five years. I'm not sure when it was originally produced. 

@gdnrbob - 10k is the impedance output - My filter goes that low (just checked a photo I took). I'm going to try it tonight and see if it works. 
Def understand- I'm not planning on selling the amp just enjoying it with my new (to me) speakers. 

Good luck and let us know what you think.
Bob

@mzwerner - WOW! I am running a similar system to yours. I have a pair of cloth Quatros I picked up just shy of a year ago, and had a DNA 0.5 GOLD upgrade done by SMcAudio this last April 2018, both a tier shy of a DNA225 Platinum and Vandy 5's. The sound is amazing. You happened into a wonderful combination KEEP IT!

The only problem with that equipment is, it shows you everything, good and bad. You will now be able to more clearly hear differences in cabling, source, etc., which can be good and bad. I liken an amp/speaker combo equivalent to a window... you just got some very clear windows, great stuff looks GREAT, and things you believed might have been good when you didn't have clear windows don't look that good now that you can see it more clearly. An example is, I have 2 SPDIF/Digital Coax cables, a Monster Cable, and an MIT. When I listened to them on my old B&K ST-202/Vandy 2C combo, I believed the Monster Cable was a better cable. With the DNA-Gold/Quatro combo, it was "clearly" obvious the MIT is the better of the two cables. It can be very disappointing to find out that some of these ridiculously priced cables, etc. actually do sound better.

@Kmckenn - just replied to you on the other thread. But, wow we do have nearly twin systems. 

So far at least everything sounds great or at least better than my old setup (which I also loved) I have some cheap monster cable. The Mccormack came with an anticable 3 power cable, which I'm using. I also have some extras that came and didn't fit on the vandy subs so I'm just using stock power cords. Should I get an adapter for them to work with the vandy's or sell them and keep stock for the vandy subs?