McCormack SMC Audio upgrades: how good are they?

Hi Luigi -

I now use Lundahl amorphous-core transformers in my amp upgrades (and in my VRE-1 preamp). I started with Jensen transformers, but switched a few years ago when I found the Lundahls offered better transparency. I originally used input transformers to provide a balanced option, but I then found that I preferred the sound of my amps with them, regardless of which input (balanced or unbalanced) I was using. First of all they provide complete immunity from DC and RFI, and well-designed units have outstanding common-mode noise rejection (CMRR). This allowed me to simplify my amp's input stage, and the net result was sound that I hear as cleaner, clearer, smoother, and more "pure" if you will excuse the expression. And keep in mind that my design handles both balanced and unbalanced signals via the same path (the only difference being the input jacks) so you get the benefit of the transformer either way. Of course this only works well with great transformers, but that is the only kind I use ;-)

In short, I feel the input transformers are a sonic benefit even if you use only the unbalanced inputs. The only downside is the relatively low 10KOhm input impedance, but this is an issue with only a small number of preamps.

Best regards,

Steve McCormack
SMc Audio

I had my DNA-1 Deluxe upgraded to the gold edition by SMC Audio. I love the sound stage improvement and the low level detail that is unmistakably there. There is less listener fatigue or "veils" lifted between the speakers and myself. I can tell as I've had this amp for many yrs. I have one issue with the upgrade which I emailed Steve's sales group and called the primary person in sales complaining about. When I turn the amp on there is a significant "POP" as they have removed the timed relay we are used to that lets the amp startup surge happen before the speakers see any current. I was told this was done to improve the sound which I countered with "Why wasn't I told this before purchase" - they forgot. Is there anyone else dealing with this?

Do you have the option of leaving the amp on continuously?

Of course it can be left on. Not sure that's the route I want to go and that was suggested by SMC.

FWIW I have run my McCormack amp continuously for a couple years, no problems; I prefer to think I'm extending its useful lifespan.

I could live with the thump if it meant my amp sounded better -- that's the point of it all, right?

I'm not sure why you mentioned it? Do you seek reassurance the amp will be fine? Are you concerned about speaker damage? No disrespect, just wondering.