Don’t buy used McCormack DNA 1990s amps

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..  

@nymarty I would direct the funds towards a purchase of a new amp and noy have the old DNA modded. 
 

@soix looks like you’ve taken on a function of being a proxy for SMc Audio to deliver a message of vested interest. No one can possibly predict when the amplifier is going to fail and I don’t recall reading much about these amps becoming boat anchors all of a sudden. 

I’ve owned DNA-0.5, DNA-125 (a good step up over the original 0.5) and the DNA-225 (amazing amplifier, one of my favorites in its stock form even to this day) that I decided to send in for a Gold revision which was a big mistake. The sonic signature changes that occurred with the revision made the amplifier pretty much go from a jaw dropping performance to being unlistenable in my system. And yes I gave it all the break in it needed. This was back in 2006 and around the time I sold that amp the revised McCormack amps would pop up on the market quiet frequently. I also saw “my” DNA-225 come up on audiogon classifieds at least 3 times (could be more but I as well as my audio buddies just stopped paying attention to McCormack amps). 

@soix

If you had any technical knowledge on electronics then you’d know that you do NOT have to build the exact same piece of electronics to understand the location and nature behind a failure. Especially when that failure is a mechanical issue in the basic board itself.

SMc isn’t saying there are deficiencies in their special top secret circuit design and they had to change this design. SMc is saying the basic board has mechanical problems. Manufacturers like SMc do not produce their own boards, they get PCB manufacturers to produce them. Whether that board is in a Kenwood, Marantz, Krell, McCormack, etc. most are from the same PCB manufacturers and run side by side on the same production line using the same processes. So anyone who has worked on repairing boards in electronics is qualified to make these statements about the repair of such.

Tell u what — I’ll go back to the guys WHO ACTUALLY BUILT THE AMP and tell you why you’re absolutely wrong..

If you do not understand that there may be a possible motivation of profit behind SMc telling people that their original amps input boards are not repairable then I do not know what to tell you. So yes, please do keep asking the fox to tend to the hen house. When you talk to SMc ask them to come onto this thread and post closeup images of the mechanical issues on these completely irreparable input boards. Certainly SMc has documented this issue many times over. There are other folks on this thread that seem knowledgeable about board repairs and I’m sure that they would like to see high resolution images of the failures too.

Your initial post reads as a person who needs to justify the expense of this purchase and is angry that others can still sell their functioning amps for a decent price.

So lets address your initial all or nothing statements,

While they’re great amps, and I happily owned a DNA 0.5 RevA for 20 years, they’re all gonna fatally fail.

No ALL DNA amps are not going to fatally fail, not by a long shot. Whether the number that survives a decade from now is my butt number of 50% or not, your statement is extreme and ridiculous. I personally believe that number will prove to be much higher than 50% and will probably be better than say a Krell or Levinson of the same vintage. BTW There’s a very good way to judge this reliability. When you begin to see far more dead DNA amp’s than working units for sale on the common audio sale sites then you can surmise that extremely high failure rates are present. I mean, based on your own opening statement, they cannot be repaired right? So they’ll remain dead until they’re sent to SMc to be upgraded or they’ll be sold as dead units and if they’ve been upgraded by SMc then the sales ad will state this fact.

Because their input board is at the end of its useful life, and when it fails your amp is dead and not repairable by anyone — not even SMcAudio. It’s a boat anchor.

Other’s have already pointed out your error in this statement. Unless a board has been completely burnt to the point it becomes conductive then it is generally repairable. However, I’ve seen boards that had burnt sections and people cut out the burnt section and P2P wired in that portion of the circuit. I’ve seen double-sided boards that literally snapped into two pieces and the tech repaired them by rebuilding each individual trace with a solid joining wire soldered to the traces and in the end creating a stronger board. In the end, whether or not a unit is repairable most of the time depends on the amount of a time and effort a tech wants to put into that unit. I’ve personally worked on a number of components over the years from the 1960’s and 70’s that had far more delicate and easily damaged circuit boards in them than the DNA input boards.

There are also some people who can make their own circuit boards, some of them look to be of decent quality.

@audphile1 

looks like you’ve taken on a function of being a proxy for SMc Audio to deliver a message of vested interest.

@kchamber 

If you do not understand that there may be a possible motivation of profit behind SMc telling people that their original amps input boards are not repairable then I do not know what to tell you.

I believe you guys are making assumptions based on facts not in evidence, and unfairly casting SMc Audio in a negative light.  If you know Steve and Patrick, you would also know that there are not many folks in the audio industry who care as much about the satisfaction of their customers as they do, and you would also know that they have had more than a steady flow of work for years now.  Steve continues to move forward with new products benefiting from his 40+ years in the business and, for him, creating high quality audio playback equipment is clearly as much or more a calling than a business.  SMc certainly do not need to add clients by fear-mongering owners of old amplifiers manufactured by the former McCormack Audio into taking action before the inevitable failure of their amplifier's input boards. 

IMO, the presentation of the OP was a bit over the top, with the whole "public service announcement", calling sellers of McCormack amps "yahoos", and then basically laying a turd on anyone who is trying to sell their McCormack amplifier.  Thanks for the warning, old stuff fails, shocker.  It seems in at least some cases, repairs are possible and unless the amps are blowing up and houses are burning down it would probably be sufficient to simply say "be aware, this could be a problem."

I suspect SMc's responses to some owners of the failed McCormack amps are similar to the analogy of how many patches do you want to put on an old bicycle inner tube?  At some point, taking the wheel and tire off and the work required to patch the tube is simply not worth the effort any more.  That doesn't mean it can't be done and it doesn't mean that the fifth or sixth patch will not hold for a year instead of a week, but the odds are against you.  In addition, patching failed input boards may simply not be aligned with SMc Audio's business plan, which includes performing high quality equipment upgrades of former McCormack Audio electronics and developing/manufacturing new products that make their customers happy.  However, as discussed in some of the posts, there are others who can make the repairs.