McCormack amp upgrade / midbass warmth?


Hi I'm seeking some experiential advice from McCormack amp owners who have had their amps upgraded by SMC Audio. I was seriously considering upgrading my stock DNA-1, until I read the recent McCormack DNA-225 review in Stereophile. He mentions that the DNA Rev. A upgrade, although being a significant overall improvement, resulted in smoothing out the midbass warmth of the stock design. I suspect the "midbass smoothing" may result from revision of the DC servo circuit? This concerns me, because I prefer that midbass-warmth sound in my system (that's why I bought this amp). Of course I am going to consult with Steve McCormack in that regard. Would just the Rev. C, or maybe even the Rev. B upgrade also affect the midbass? I don't want to lose this warm sonic signature, it works nicely in my rig. I hope to hear from others who have done upgrades please? Thank you for sharing any opinions.
bob_bundus
I tried recently, to get at the difference between these amps. According to the Stereophile review, a Rev B amp is on par with the new design. According to Steve McCormack, who admittedly "danced" around my question, it might take a Rev A upgrade to get at the new design. It might be that Mr McCormack's interest (financially) in McCormack Audio, and in SMc Audio may cause problems with his recommendations of either one over the other. This is only speculation on my part. Mr McCormack was very, very helpful with my questions. He wrote two emails to me in extreme detail. However, I am no more sure of the differences now than I was before. Perhaps it really is not "better" but different.
I haven't heard the 225. I do have a DNA-1 Deluxe that was upgraded to full Revision A Gold, except for the balanced inputs, this past summer. I absolutely love this amp and the difference is incredible. I would easily do it all over again. I also believe that there are a lot of very good products out there and many factors that might influence your preference. If it helps, I'm using CAL Delta transport into a Classe DAC 1, and an Audible Illusions Modulus 3A with Thiel CS3.6 speakers. My room is 16x24 with a cathedral ceiling. All power cords have been upgraded and the interconnects are Transparent Ultra XL's.
I find it hard to believe that a 2700 retail amp can compete with a hot-rod amp that has had 1500 in upgrade parts alone. I talked to steve's technician, and he said I would have higher performance from a hot-rod dna amp. His argument being that the quality of parts found in the Rev A gold would only be seen in 7-8000 amps. I have to agree with him. I'm sure the markup is 30-40% at the retail level. I have not heard the dna225, but I did own the RevAGold and I think it's one of the best solid state amps I've ever heard. Tremendous bass with excellent soundstaging. Good imaging, very neutral with very little solid state grain. I thought it was very enjoyable to listen to. For a big speaker like the vandersteen 3a's, this is a top wonderful choice.
"He mentions that the DNA Rev. A upgrade, although being a significant overall improvement, resulted in smoothing out the midbass warmth of the stock design." Smoothing does not mean that the Rev. A lacks warmth, only that it is forward in the midbass. "I suspect the "midbass smoothing" may result from revision of the DC servo circuit?" Or it's removal!
Thanks for your comments: I'm still unsure about this, but the ONLY way to determine the answer is via home audition (duh). However I'm first going to try out the Belles 150A Bartha Mod amp, at about the same $. From what I've read this Hitachi mosfet output amp may be just what I want.
Yikes! What i meant to say is that the Rev. A DNA-1 is NOT forward in the midbass. It does not lack warmth. I prefer it to the DNA-225. BTW, I have heard that late-production DNA-1s had reliability problems related to the PCB used. This is hearsay. OTOH, my two early ones have been trouble-free.