Don’t buy used McCormack DNA 1990s amps

Photodusty - Yes, the circuit boards are the same in the DNA-1 Standard & Deluxe. The difference was in the higher-performance / more-expensive parts used in key circuit locations in the Deluxe model. This included resistors, capacitors, diodes, wire, and connectors.

The new main board I designed as a replacement upgrade (called the "R3 board") fits both the DNA-1 & DNA-0.5 amps.

Pereza - I'm glad to hear that you're enjoying your DNA-500 - it's a fine amp. The reason we don't offer upgrades for it any more has nothing to do with its circuit boards or any reliability issue - it's just so big and heavy that it becomes a major pain to work on and thus costs a lot more than we feel makes sense. I hope you will continue to enjoy it.

Steve McCormack

@stevemcx 

Thanks for chiming in here.  I've enjoyed your recent vids with Audiophile junkie.

After your initial post I thought my 0.5 was off the hook!  Oh well.  It is over 20 yrs old after all.  I will have to get it back in the system soon and see what happens.  

Your DNA-0.5 may be just fine. They have held-up better overall than the DNA-1. Give us a call if you have any questions.

Steve M

@stevemcx Thanks for chiming in here Steve — most helpful.  Not to get too much into the weeds here, but I’d think since I assume both the DNA-1 and 0.5 input boards were designed around the same time and assuming they’re more alike than different, what makes the DNA-1 board more prone to failure, or, what makes the 0.5 board less prone to failure?  Just curious because that’s very interesting.  Sorry to take your time, but thanks for any thoughts. 

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