McCormack DNA .5? Do I need more power?

Hi. I have been thinking about picking up a used McCormack DNA 0.5, which I may upgrade in the future. Will it be powerful enough at only 100w? I am currently using a B&K Reference 4420 (225wpc) and while it sounds good, I am sure I will get better sound out of the McCormack, especially once upgraded. My speakers are 91db, pretty efficient, but they have a big 10" driver along with a 6.5" driver, 1" driver, and tweeter, so I don't want to under-power them. Manufacturer recommends no less than 30w. I don't play real loud (no higher than 10 o'clock, which is plenty), but I don't want the lows to be muddled by a lack of power. What do you think?
I use a Rev A modded DNA .5 to drive Spendor 9/1 3-way speakers which have a 12" woofer. I think the speakers have an efficiency of 89 db SPL. Another consideration is the match of the amp with your preamp. The SMcAudio revisions make a sweet-sounding amp even better. JimL
It's more a matter of efficiency and impediance than raw power wattage. Your speakers are pretty efficient at 91db, and I'll bet they are considered 4 ohm's. That makes the McCormack a 200 watt amp into 4 ohms.

Plenty of power there to control your woofer. The McCormack's are also known for their tight and tuneful bass, so I wouldn't think you would have a problem.

And yes, the upgrades steve offers are not to be dismissed lightly. If you like the DNA .5 in its stock form you will be amazed at a Rev A or B unit. Never to upgrade again is what most of us think of those mods.

I have Vandersteen 2CE Signatures @ efficiency of 86DB. I had the B&K 4420 driving them but moved to a McCormack DNA-1. 150 channel into 8 but probably running close to 200 because the Vandys are 7 ohms I think. The unmodded DNA-1 provides plenty of power with more to spare so I think your 91 DB spendors would mate well with the DNA .5 as long as your room isn't too big and you are not looking to blow the roof off your house....

I don't know if you'll "need" more power, but a DNA-1 is not that much more expensive than a DNA .5. More power is usually "better", even if you don't absolutely need it.....
The McCormack 0.5 has a very conservative rating of 100 watts per channel, sounds much more powerful. I have had other power amps rated at 200 watts per channel that can't keep up with the 0.5. This amp has unlimited power reserves & I have yet to clip mine. By the way, I own the DNA 0.5 Rev A, offers a world class sound and easily beats most everything I have heard before it. Your above speakers at their efficientcy of 91 db would produce concert hall levels with the 0.5.
Anyone ever use a McCormack DNA .5 stock or Deluxe to power a pair of KEF 104/2 speakers? Anyone care to share their thoughts on how the combination sounded? Did the DNA .5 provide enough power to them?

Specs of the KEF 104/2s.

Model 104/2 Specifications:
Frequency Range: 55Hz - 20kHz ( 2dB)
Drive Units:HF: T33 25mm (1") Impregnated fabric dome
MF: 2 x B110 100mm (5") Doped Bextrene cone
LF: 2 x B200 200mm (8") Paper cone
Crossover Point:150Hz, 3kHz
Nominal Impedance: 4 ohms
Characteristic Sensitivity Level: 92dB
Amplifier Requirements: 25-200W into 4 ohms
Maximum Output: 112dB
Internal Volumes: LF 50 litres, MF 3 litres
Net Weight: 32kg (70.5lbs)
Dimensions: (H x W x D)900 x 280 x 415mm, 35.5 x 11 x 16.4 ins

It's a great amp, but I had to get rid of my Rev. A due to clipping my Maggie 1.6's Everything was fine until a low bass note was played and the speakers would make a "snap" sound. The 1.6 just sucked the juice out of that amp. Moving to a W4S ICE amp fixed it of course. At 91db efficiency you will be OK. I just wanted to let everyone know there is a limit to what that or any 100 watt amp can do.
Hi Koestner

Thanks for sharing your thoughts and experience with the DNA .5. I'm hoping to get a DNA .5 soon and see how the little guy does with my KEFs. I had a DNA 1 Deluxe before with the KEF 104/2s and I liked the sound was really revealing but it may have been too much power for the speakers.
Koestner, you are correct sir, there is a limit to what even the McCormack DNA 0.5 can do. Seven years ago on my above post (wow where did the time go?) I was using very efficient speakers that had a sensitvity of 102 db. It was no wonder I thought the 0.5 might have unlimited power reserves. Your Maggies are much more difficult to drive as you mentioned. I could see how ice power did the job nicely. If you or anyone else on this thread sends me an email, I will send an interior picture of analog amps that can drive any speaker regardless of its efficiency rating to high volumes without clipping!
I tried my old McCormack DNA.5 on a set of Maggie 3.5's. It sounded good, with a tighter bass than the ARC gear in the showroom. But it didn't have that tube bloom that the ARC provided and made the Maggie's sound magical. Of course the bass was plummy with the ARC gear, so that was a non starter for me also.

I've since upgraded to a DNA500 and will never lack for power, or finesse, again.
"Anyone ever use a McCormack DNA .5 stock or Deluxe to power a pair of KEF 104/2 speakers?"

You might want to try contacting Bside123, I think he has that combination and likes the way they work together.
Hi: Yes, I really like the McCormack DNA 0.5 / KEF 104.2 combo. I've owned 3 pairs of 104s over the years. I really love that speaker. Even after I moved on to other speakers, whenever I've run into a good deal (deal that cannot be refused) on a set of KEF 104.2s, I've bought them.

I am also a fan of the DNA series of McCormack amps... particularly the 0.5. I've also owned several iterations of these over the years. Currently, I am using McCormack Mono Blocks that started out and .5's as well as I am using a DNA 0.5 Ultra Platinum Upgrade in another system.

I think that you'll find the DNA 0.5 is more than adequate to run the KEFs. As a matter of fact, I found it superb. Consequently, I sold my last pair of 104s to a nephew, who is driving them with a 0.5 Deluxe!

I am still a lover of the KEF 104.2s, but currently I am using Dunlavy towers. I also use a set of stand mounted Acoustic Zen Adagio Jr speakers, which in exception for a ribbon tweeter, are not too dissimilar to the 104.2s in their conception and design configuration.

Hope this helps.
Thanks you guys for chiming in.

I saw your response in the thread about best homemade tweaks and when I get the DNA .5 I may try that EAR Isodamp under the transformer and some rope caulk in the corners. No way am I trying to apply caulk to the caps or PCB.

Thanks again for the help. Man you have a lot of McCormack gear.

Many thanks for sharing your experience. It definitely does help. I think you have more McCormack gear than Ig316b. What Dunlavy's are you currently using? The AZ Adagio Jr's look quite nice and can see the resemblance to the KEF 104/2s. I haven't had a chance to investigate the AZ Adagio line but I wonder if they are using internal woofers as well. I never really looked at them as they are just too expensive for me.

So you can't pass up the KEF 104/2s either. I have a pair of KEF Q-90 speakers and saw a pair of KEF 104/2s in great condition at a fair price not too far away from my house. I had to scoop them up. I initially thought they looked ugly in pictures but when I saw them in person they really grew on me.

I can't wait to get my DNA .5 Deluxe and hook them up to the 104/2s.

Thanks again.
Hi Jedinite24: I have two pairs of Dunlavy speakers: SC-II & SC-III. They sound very different from each other in my opinion. I like them both fine. Both models image superbly. The IIs are 2-way and are very dynamic; the IIIs are 3-way and are a bit more hi-fi sounding but have a broader soundstage and give a fuller total presentation from top to bottom. Both models like power!

The Adagio Jr speakers do not have an internal woofer like the 104.2s down firing driver. However, the Adagios are also ported, but the port is in the rear. Even the Jr's move a lot of air and the bass response is a bit lower than the 104s. My experience is that placement of the Adagios is really critical and they are more demanding in placement than the 104.2s.

Best regards. "If you or anyone else on this thread sends me an email, I will send an interior picture of analog amps ... go ahead and send me those pix. Not sure if you can email me thru this but let's see. curious about those amps. Thanks,
Hi Luis

When PHD made that post it was a different time on Audiogon. You could contact members privately and correspond with them via e-mail in addition to the forum. Nowadays the only way you can contact a member is if that person has an classified ad posted.

If you want to run the risk of posting your e-mail address in the forum you can do that as well so PHD or anyone else can send you what you want.
Jedinite24 is correct. Under the new audiogon it would be impossible to send pictures directly to you. But if you contact my email address: I will respond with pics.