McCormack REV B upgrades. Better than a new amp?

You should consider contacting Steve McCormack. I've found him to be most helpful, and I'm sure he or Chris would be upfront with you on the differences you can expect between the Rev. B and Rev. A, etc. When I spoke to Steve a looooong time ago he implied there is a big difference between B and A, but can't remember specifics (I think the power supply was significant) and what the final effect on sound was.

I seem to see 0.5 Rev. As come up from time to time, so the wait might not be as bad as you think if it's truly a big stepup on performance. I'll certainly keep my fingers crossed for ya.

Old thread but related question.
Have  an opportunity to buy a DNA 0.5 rev B. 2nd Owner  and does not know when the rev B was done.  Was talking to an eng at CJ (CJ have taken over support for McC) and he told me that after 20-30 years, some of the caps have to replaced.Is it worth buy this DNA 0.5 with rev B given that the rev B was probably done 20 years ago?I am planning to power my Vandersteen 3a signatures. I would have preferred DNA 1 or DNA 225 as they have more pwer but harder to comeby.
My alternative is to buy a new MF integrated  for around 2K.New Belles Aria separates would be a very fantastic fit for my Vandys 3a  but they are $4.5K and out of my budget

Unfortunately the caps by far are not the biggest problem.  McAmps of that age have input boards that are now failing, which is fatal because there’s no repair for it so the amp is basically toast and requires a total rebuild.  You can speak with Steve McCormack about it at SMcAudio (I did) where they still do their awesome mods for the DNA amps and their other stuff, but I wouldn’t touch that amp if I was you.  Caveat emptor. 

If you planned on going the SMC upgrade path, buy a McCormack amp, and upgrade it.

 Heard lots of people buying non working McCormack amps for a steal, sending to be upgraded, your getting a new amp, which is of top tier quality and workmanship.