Don’t buy used McCormack DNA 1990s amps

The DNA-1 design predates the DNA-0.5 by around 2 years. I made several changes to the circuit design for the 0.5, and its circuit boards were a bit smaller and not as complex as the DNA-1. There is a central ground area on the DNA-1 board that is the location of most of the through-plating failures, and this was done differently on the DNA-0.5 board. In the end, the original DNA-0.5 board is a bit smaller, less complex, and less prone to through-plating failures - although as Pat has pointed-out, we have begun to see these failures in the past few years.

I designed an all-new circuit board (called the R3) a few years back when it became clear that working on the original boards was a losing battle. With some careful layout it was possible to make one board that fits both amps, so that was a welcome bit of efficiency. In addition, the quality of the boards we get now is exceptional, and better than the originals.

Steve M

All upgrades still available for the the dna750 monos.

LD-2 ?

not for the UDP-1?

Thanks for your interest. Yes on the LD-2, but no on the 750 monos and the UDP-1. We have never done upgrade work on the UDP-1, but we have done a few pairs of the 750 monoblocks in the past, but no longer. Like the DNA-2, DNA-500, the 750 monos are just too big and heavy for an efficient workflow. They eat up too much time and are too expensive to be practical.

Steve M

#@&&%%**#$

Damn, I spoke with you and Pat about a year ago, and was given a price for capacitor upgrade, and a bunch of other stuff. 
  Fingers crossed for reliability. 
never had good luck with my gear. 
 

I will have to add 750s’ to my kids nightly prayers.

well, if and when there is a breakdown, I will give a call and ask if you have the time for gold+ revision. 
 

cheers Steve, great week. 

@soix 

Are you able to give us sonic impressions of your upgrade yet?