Too many accolades have been heaped on the Power Drive DNA-1 for me to ignore it any longer. Since its introduction in 1992, this amp has been a favorite of not only the press but of many audiophiles whose ears I trust. I hesitated for a long time. There was the fear of possibly LIKING it, possibly LOVING it, and possibly not wanting to part with it. Yes, doing these reviews is work, but loving something is certainly one of the nicest downsides that a person could have to a job.
The DNA-1 was designed by Steve McCormack, with the input of Joyce Dudney-Fleming. It has been on the market since 1992, and currently McCormack offers a "deluxe" version, with upgraded parts for an additional $350.00. Those of you who own the "standard" DNA-1 (I cringed when I wrote "standard"; please don't assosciate the word "average" with it), can send your amp back for mods. Contact the factory for a quote.
When I first talked to Joyce, she asked me whether I would like to report on the standard or the deluxe package. I scratched my head momentarily and decided that workin' class people like me might like to trim their budgets a bit, so I opted for the standard version.
The DNA-1 is nothing short of beautiful to me--I'm talking simple, mechanical beauty. The resemblance is akin to a brand new King Cab--full size, beefy, all GMC--and no flashy Ferrari. As far as I'm concerned, I'm into function vis-à-vis sound quality. Save the window dressings for the day I hit the lottery.
The faceplate is 1/4" thick aluminum, with a mill finish. Other than the McCormack logo, a rocker on/off switch and LEDs for power and protect mode are all to be found on the front. If all is as should be, the protection light fades out after about 10 seconds. The faceplate sports rounded corners, and the bottom edge does a little turnout at the middle, to jazz things up a tad. Simple elegance. McCormack opts to leave the heat sinks exposed, I assume for maximum ventilation purposes. This is another touch I prefer cosmetically.
The rear panel sports an IEC socket for a detachable power cord. The manufacturer recommends if you have any hum problems from ground loops that you leave the DNA-1 grounded and you float other components. My personal advice is before you worry about ground loops, check all your cable routing. If you've got AC lines running near or parallel to interconnects and speaker cables, say hello to the EMI Fairy. Eliminate this before you decide to float the grounds.
Also on the back panel are a pair of RCA jacks for input interconnects, an AC main fuse, and two pairs of binding posts (with plastic caps), as well as two pair of phillips-head spade connectors., which I really like. After all, this is a "contact sport" and the screw-down connectors offer one of the most secure connections I've seen. Not only do you get your preference of how to connect your speaker cable wire or spades, you can also bi-wire, since the connections are wired in parallel. Nice touch! I had been using a set of Cardas Crosslink single bi-wire speaker cables previously, and now can run a separate pair of single run cables, to the high and low frequency inputs of the PSB Stratus Golds. The bass became faster, and imaging showed a small gain.
Removing 14 small screws will allow you to take off the lid and gain full access to the electronics. Now, I'm not an electronics major, but I've been around enough to know a well-built product when I see one. The transformer is massive, and of the of the E-core type, as opposed to toroidal, and shielding of the transformer with copper sheeting prevents EMI. The input and driver stages are laid out beautifully on a circuit board in the middle-rear section, behind the transformer. The output stages are left and right of the transformer, input and driver stages and attached to the exterior heatsink fins and protected by two 10-amp fast-blow fuses per channel. The DNA-1 operates in a push-pull configuration. All soldering looks immaculate, and if I had to guess, I would say a lot of hand assembly goes into the product.
The base of the Power Drive DNA-1 has four "soft shoes" attached for damping chassis vibrations. Because of the footers' composition, McCormack also supplies four coasters to eliminate any possibility of the feet gumming up the finish of your shelves--not a problem with the piece of tempered glass I use in my home-brew sandbox isolation base. Also supplied is a small threaded mechanical grounding spike. With this installed, the amp tilts slightly from rear to front. While I'm a little confused by the practice of using both a spike and cushioney feet, I trust the judgment of McCormack and installed the pointed spike. Can I hear any difference with or without it? Not really, but it's there and I'm not gonna make a stink over it. If you don't want it, don't put it in.
WARNING: possible RAVE alert! Now I know that by throwing well-deserved praise around, I'm gonna get some nasty mail from the "ain't no way it could be that good" crowd. But, I calls 'em like I sees 'em, and this amp pushes all my buttons. You ever paid to have your ass kicked? Well, that's what's gonna happen if you let loose of two grand on this baby. It's an ass-kicking product when need be, and a sweetheart for those kinder, more gentler moments.
Don't expect the DNA-1 to jump right out of the box, and impress you a whole lot. McCormack recommends a minimum of 50 hours of burn-in. I'd say it was close to that before I noticed the changes I was looking for, and probably another 20 hours before I was satisfied that it was time to get to know this amp a little better. After two complete days of burn-in, using track 20 on the third Stereophile test CD, the amp began to open up and bring me into the music.
Yet it was only after another 20 hours or so of running before I felt the bass had settled in properly. Why this would be, I don't know. Prior to this point, I wouldn't say the bass was "bloated," but it was not as differentiated as I would expect. When the bass finally did come to fruition, I was very pleased at how clean, tight and extended it was. I prefer the kind of bass the McCormack offers. Every note is separate from others, and at no time does this amp seem to overplay the low-end frequencies and create an imbalance with the rest of the spectrum. It was while listening to "Divergence" on the new Christian McBride Number Two Express disc (Verve 314 529 585-2), that I knew things were gonna be all right. This is not the most transparent recording I've heard (but still great music), yet the plucked-string bass came through wonderfully, helping the aggressive drum work provide the drive for this moving jazz progression. Put on Flight of the Cosmic Hippo by Bela Fleck and the Flecktones (Warner Bros. 9 26562-2) and the McCormack Power Drive DNA-1 will go right on down to bass hell with Victor Lemonte Wooten's "use me as a test disc" electric bass lines. Tight and taught all the way, with just a shade of roundness to each note that lets you know this is the real deal.
The midrange is everything you could ask for. Most male and female vocals will tell the story, but don't forget the midrange is also where you'll find most of the instruments hanging out. Roy Hargrove's trumpet on the wonderful disc "Parker's Mood" (Verve 314 527 907-2) is outstandingly reproduced. With quality components surrounding the McCormack, you're treated to brass as brass should sound. When Muddy Waters sets force upon the line "My wheel mule's crippled, my lead mule's blind" on "My Captain" (Mobile Fidelity UDCD 593) not only does the liquidity of his vocal show through on the soft second half of the phrase, but the transient attack when he screams the word "wheel" is scary. Fast attack with an oh so delicate decay. Rebecca Pigeon's voice on "Spanish Harlem" (The Ultimate Demonstration Disc-Chesky UD95) is silky only when reproduced properly, and with the DNA-1 it is. During the last line, when she sings "in my garden," lesser equipment lends a hollow sound underlying these three words. Not this amp.
The upper registers, classically defined with cymbals, violins, and little tinkley percussive things (phrasing all mine), performs admirably. At no time did I ever find the music to be closed in by a rolled-off treble, nor did it err to the extreme and lend any less than lifelike sound to cymbals. It's a sweet treble that shone when I played The Modern Jazz Quartet at Music Inn: Guest Artist Sonny Rollins (Mobile Fidelity UDCD 632). Connie Kay's drum work emphasizes the cymbals, and any problems with the treble here would make it difficult to enjoy this disc. As well, Milt Jackson's vibraphone would be spoiled with any edge or grain. Neither would be the fault of the Power Drive DNA-1, as I've heard it perform splendidly in my system.
So now you get all that right, and you hope the rest of the equation balances. On top of truth of timbre, perceived tonal balance, and proper handling of dynamic range, give me a spacious soundstage and I'll be happy. Yup, I want it all. And you should too. That's hard earned money were chucking out. Without any reservations, the DNA-1 will do it all. Depth is as good as the recording and your other equipment will allow. Images float gracefully about the entire front end of my room, and almost 90 degrees parallel to me when playing Roger Water's "Amused to Death" (Columbia CK 47127). The recent addition of the revision A/D chip to my Audio Alchemy DTI.PRO 32 increased the bloom, depth and width of the soundstage. The DNA-1 didn't stand in the way of these improvements, which were effortlessly detected. And after the DNA-1 did all these nice things for me, I turned around and got mean with it. I cranked the volume knob as far as I could stand, and I couldn't get the amp to clip. Now either this means my threshold for pain is too low, or the DNA-1 can really put out some current. My PSB Stratus Golds are nominal four ohms, and they don't hesitate to ask for extra juice on the dynamic stuff. Someone dig up some measurements on this amp and send them to me. I'd love to see how my impressions stack up.
I bought the DNA-1. I had no choice. It took me hostage, and told me what a fool I'd be if I sent it packing. I'll be listening to other amps along the way, but based on what I've heard over the years, the McCormack Power Drive DNA-1 will stand proudly against all comers in its price range. I'm thinking it'll hold its ground with a few more expensive amps as well. This is a true Workin' Person's product--emotionally involving, and an excellent value for your cash (or plastic). But don't trust my word. Take one home and give it a workout. If you end up short in the wallet afterwards, you'll know where I've been.
McCormack Audio Corporation
I enjoy the envious position of not only expecting every Power Drive DNA-1 review to be a rave, but of having these expectations fulfilled every time. Steven McCormack got this design just right and we expect to keep it in production for many more years.
DNA stands for Distributed Node Amplifier. That means instead of the usual handful of big storage capacitors in the middle of the amp, Steven uses a smaller capacitor placed directly beside each output device, giving each one a dedicated power reservoir. The result: faster, cleaner music at a lower price.
We use the DNA design concept in all our power amplifiers. The DNA-1 already has two little brothers--the 100 watt DNA-0.5 and the 50 watt Micro Power Drive. And there's another on the way: the Power Drive DNA-2. No, this is not a replacement for the DNA-1, instead it is the same basic design executed in a truly balanced configuration. The DNA-2 will make it's debut at WCES in January, 1997, where it will appear in its Limited Anniversary Edition finery. (See, started business in 1982, so next year we celebrate our 15th Anniversary...or is it our 15th birthday?) We will make only 500 of these beauties before starting production on the Standard and Deluxe models which we fully expect to become classics in their own right.
Thank you for telling your readers about McCormack Audio's most popular product. I know they will enjoy listening to it as well.
Joyce Dudney Fleming
DNA Technical Specifications