Krell KSA100 vs Threshold 400A vs McCormack DNA 0.5

As mentioned above, give Steve McCormack a call at SMc Audio.  He will tell you what he can do for a .5 and the cost to you.  Steve is a straight shooter and you may be amazed at what he can do for the .5 for the cost!

The DNA  (distributed node amplifier) design concept has truly stood the test of time.  The quick response to the input signal sets it apart from other fine amps.

To clarify...

The SMcAudio upgraded DNA amps have a wonderful textural smoothness and treble sweetnesss.  The greatest transformation is probably the huge soundstage.  @4hannons  Bingo on "clear".  The modded amps allow you to "see" deep into the soundstage.👂

@labtec  +1!  Everything you said about what Steve McCormack can do for you is accurate.  If you decide to modify an "older" McC. amp. they send you a questionnaire about your system and listening preferences so they can tailor their modifications to your amp to optimize its performance with your speakers and associated gear.  Extremely reasonable price for the depth of the modifications.

@legarem   Congratulations!!  Great decision!  Many folks who were experienced listening to the .5 and the DNA-1 preferred the .5 for its sweetness.  So... you will have a nice sounding amp from the get go with the option to max. it out down the road with SMc Audio's upgrades. Happy listening.👂

@legarem 

What does the seller have to say about the condition of the amplifier he sold you?  IMHO he should finance the new driver board you made or let you return it to him for a refund.

 Steve is being absolutely truthful.  Same thing he told me about my 21 year old DNA-1.  They are seeing a consistent pattern in the degradation of the driver board over time.  It is just not the unrepairable nature of the amp but rather that in the years that have passed, Steve has been refining his modifications to the DNA amps.  My previously modded DNA-1 was $1300 for a new driver board, wiring, input and output jacks and new improved soft recovery diodes.

The amplifier is now reference class!  It really is fabulous.  I almost feel guilty getting that much bang for the buck.

If you don't have the money now I can see how that is a problem in your case.,  But... you can't expect SMc Audio to repair something that is going to fail soon again.  

Steve is not doing that.  When I called Steve about updating the 18 year old mod. on my DNA-1 Deluxe, the first thing he told me was that if I sent it in they would have to replace the Driver Board as that is the part of the amplifier experiencing failure issues.  He offered to do more than that but said he could not repair the old driver board for reliability reasons, but that the board would be replaced by a new upgraded board.

Once the new board is in place you are good to go.  I went ahead and had the "Gold Special" upgrade done.  It sounds great and I have every expectation it will outlive me.