Don’t buy used McCormack DNA 1990s amps

However, I’d be willing to bet that 50% or more of them will still be kicking with their original input boards 10 years from now.

@kchamber You’d be willing to bet based on what? Faith? Other people’s money? Where does 50% even come from? Outta your butt? You’re willing to “bet” means precisely ZERO to someone buying one of these amps. And by the way, who wants to buy an amp with a 50% failure rate even if you’re right, which you probably are not. The design is prone to failure, especially after 20+ years for the reasons stated by the guys who built the amps, which is not you. Period.

@soix 

Convinced of your belief, you are being harsh and extreme, IME. You also have no basis to claim the converse-that every 1990's McCormack amp has either failed or is on the verge of failing. IMO, kchamber's viewpoint is likely more realistic. I can not think of too many consumer products that have had a 100% failure rate, not even the dreaded Yugo. 

@soix 

You're correct I pulled that number out of my butt, using nothing but my 35yrs of experience designing and working on electronics in semiconductor manufacturing and research.

Guess what? Krell & Levinson amps of the same vintage are also very failure prone. In fact, probably more so for some models due to heat stress. The people buying those 30yr old amps for kilobucks do not seem to care? Does that make you angry too?

Anyone that is really concerned about one of these DNA amps failing should invest in having a true DC protection circuit installed by a competent tech. That includes the new input boards that SMc is selling because they do not have true DC output protection either. The DC protection in the older DNA amps is only an input muting circuit.

@fsonicsmith1 

I'm located near Dallas. I mainly do work for local audiophiles because I work as a research engineer M - F so this audio work is done in my spare time. I do some work on Acurus and Aragon preamps for folks around the country. I have a set of specific upgrades for those preamps. I used to take in various amps from people around the country but it became too much for me to keep up with so I had to stop taking in amps. I now only accept amps from local audiophiles. I have a full array of test equipment and can fully test amps up to over 1000WPC on my bench using an Audio Precision analyzer.

You're correct I pulled that number out of my butt, using nothing but my 35yrs of experience designing and working on electronics in semiconductor manufacturing and research.
 

Yes, you pulled that number outta your butt.  But you don’t have 35 years working with McCormack amps, nor did you design or build them.  I’m spreading info from the guys WHO ACTUALLY BUILT THE AMPS.  Tell u what — I’ll go back to the guys WHO ACTUALLY BUILT THE AMP and tell you why you’re absolutely wrong..