McCormack DNA 500 vs DNA 225 upgraded

I have heard pretty much the same thing Cmach posts above from Steve McCormack. However, your question is pretty much answered in posts made by Steve in a thread titled;

"McCormack DNA500 and DNA2"

You might also want to check out a thread titled;

"McCormack DNA-225 Platinum Edition Upgrades Amplifier"

The used prices of DNA 500's right now are hard to beat. The DNA 500 is a very nice amp, although IMO not quite to the level presented in the IAR review. I would only go to a modded 225 if I was going to get the top platinum mod and have them converted to monoblocks. The first pair I have seen posted for sale here was only about a month or so ago.

One benefit of the DNA 225 over the DNA 500 is the input impedance. I owned the 500 and the 10k ohm input impedance limits your choices of tube preamps that won't result in an impedance mismatch (rolled off bass and highs). The DNA 225's input impedance is 100k ohms so it matches with a wider variety of tube preamps (output impedances). I've learned through experience and through the benefit of experienced members here.

The DNA 250 is said to run considerably hotter than the DNA 500--not sure whether that matters in your application.

I had a DNA .5 Rev A and just picked up a DNA 500 used. The same house sound is present in both of these amps. Obviously the headroom on the 500 is just over the top, giving it better dynamics and more "pop". I also really do not need my subwoofer anymore since the bottom end is just deeper and more controlled. There is also an increased soundstage depth and width and presence over the .5 Rev A, by a smidge. My tube preamp mates well with it, but the impediance is a concern for some so check into it. The 500 is also balanced, so you may get more bang for your buck if you have a balanced preamp and source to use with it.

If you like the Mccormack house sound you can't go wrong with either.

In my above post, I reference a thread which should have been titled:
"McCormack DNA-225 Platinum Edition Upgrades"
(without the word "amplifier" after it)
In that thread, the reviewer/poster states;

I would recommend a transformer-based passive or very neutral tube pre with this amp so that the full luster of the DNA-225 can be realized. In original configuration (100Kohms input impedance) the DNA-225 was a bit particular about volume control. While a high quality and finely stepped attenuator is still crucial, in my mind, it is not as much so given the new input impedance of 10Kohm.

Not quite sure what he is getting at regarding volume control, but his post implies the upgraded DNA225 may have an input impedance of only 10K ohms, which would restrict the preamps you might use to those having output impedance of less than about 500 to 1,000 ohms across their bandwidth.

Also, there used to be some posts around here from someone who had their DNA500 upgraded, although I could no longer find them. I know the DNA500 upgrades are not posted on the SMc website, but I believe there may be a few things Steve can do to improve that amp sonically, and also to provide a higher input impedance by using transformers. If that is a direction you want to go, you should check with Steve/SMc.