Best option for Amp upgrade...

while I agree that usually degraded older caps/parts and modded products not holding value are often important issues, I don't think these apply to SMc upgraded products...

     I do not doubt having the full SMc mod performed on your McCormack DNA 500 amp would likely improve its performance and that key vulnerable internal parts could be replaced at the same time.  But it is expensive and while the amp design may still be very good it is also now about 15 years old.

      I've never tried the DNA 500 in my system, but I am aware of this amp's excellent reputation of  being powerful and stable enough to drive virtually any speakers while also possessing a very detailed, refined and musical mid-range and treble.  A revolutionary design/amp that probably will continue to sound very good until it  is unable to continue due to some unexpected cause.

     The main reason I thought of the D-Sonic M3-1500 class D monos as a good solution for your situation is because I think their performance and strengths are very similar to the DNA 500's performance and strengths: extremely powerful, very high damping factors for solid bass control, high reserves of power for live-like dynamics along with a very detailed, refined mid-range and treble response that is never excessively bright or brittle.  

     However, the D-Sonic monos are based on very recent advances within a newer technology, class D amplification, which may scare off some overly risk averse or unadventurous individuals.  I just think you'll be pleasantly surprised how reasonably priced, reasonably sized, electrically efficient, cool running and great sounding these mono-blocks are.  
     I definitely would urge you to give them a 30-day audition in your system before spending considerably more on any alternate option.

Best wishes,
   Tim

      

shoff-
how do you like the combo sound of the CJ ET-3SE and DNA 500?
Happy Listening!

Those who mentioned the resale value of an upgraded amp being less than a similarly priced new amp are correct.  Therefore, you need to decide if you plan to keep and listen to the amp because you like how it sounds, or if you are more likely to get on the buy/sell merry-go-round.  If you like the amp, and just want to make it even better, then the SMc upgrades are a great value.  If your goal is a better resale margin, then the upgrades are not for you. 

I wouldn't worry about the age of that amp....it is a very good design and built like a rock.  It will be dead nuts quiet and totally reliable when Steve is done with it.  As I recall from owning the DNA-500, and using it with a wide variety of tubed preamps and mostly with a Tom Evans Vibe/Pulse SS preamp, the amp displayed very good clarity, dynamic, hard-hitting bass, and good dimensionality.  The weak point was a small bit of wispiness in the treble, which Steve says is corrected as part of the upgrades.  I do not remember resolution and detail being issues with that amp.  Maybe you need to try a SS preamp like the Tom Evans or better yet, Steve's own TLC-1 with Signature upgrades, which is the best preamp I have owned out of about 20, including several that were north of $10K.  

Thanks to all who have responded.  I appreciate those of you who warned me of about recouping the cost of the modification if I were to sell.  I am very aware of this and almost mentioned it preemptively in my original post.  In retrospect I think I should have.  10 cents on the dollar sounds about right!  I should also mention that I'm in my mid 70's and which ever route I go, this will definitely be my last amplifier adventure.  So, if a dubious financial investment yields the best sound, I'm OK with that!


To address a few comments and questions raised so far:

(1) The DNA 500 is more "powerful" than the JC 1's.  (500-900 wpc vs. 400-800)  Not sure how this translates to actual "current".
(2) All of my cabling is Transparent.  The interconnects are the latest Gen 5 Super models, and the tube in my CJ is an NOS 1960 Amperex.
(3) I do like the pairing of the CJ ET3-SE with the McCormack.  I tried a Manley Jumbo Shrimp and VAC before settling on the CJ.
(4) I will checkout the new Bryston.  Thanks for that and the other recommendations.
(5) I'm impressed with all the positive comments regarding the SMC modifications.  Sounds like a very good guy!