Review of Dartzeel NHB-108 Amplifier


Dartzeel is a relatively new entry to the high-end game. Despite being reviewed by John Marks in a recent issue of Stereophile, the company's only current product offering, the NHB-108 stereo amplifier, hasn't gotten a lot of press on these shores. Hopefully this "review" will do its part in rectifying that.
As many of you probably already know, Switzerland-based Dartzeel is the brainchild of one Herve Deletraz. Herve is a wonderful guy who's dedicated to the very best customer service. As essentially a one-man operation, I'm sure his time is limited, but he's always responded to my e-mails in an extremely courteous, timely manner.

On to the amp. I'm not one for technical details, so I'll leave them to those of you who want to visit Dartzeel's website. Basically, the 108 is a "purist" stereo amp rated at a relatively modest 100 wpc. Its smallish dimensions belie its weight, which measures around 65-70 pounds.

Internally, the amp is incredibly well laid out (if tightly packed), with an attention to detail that one should expect--but doesn't always receive--from components in this price range.

Outside, it's purely love-hate. (Refer to the website for pictures). Either you get it or you don't. Personally, I've grown used to its appearance over time, but it's taken a while to become acclimated. If WAF factor is any sort of issue, practice up on your compliments. Then again, I may be overstating the case. While it's not Liv Tyler, it's not Janet Reno, either. Time reveals its inner beauty.

Performance-wise it's a much more straightforward issue. In my experience the 108 is the most balanced, natural-sounding amp I've ever heard. It has a way with timbre that's downright spooky--up there with the very best tube units one cares to mention. The sound is just "right"--every note is reproduced with a tonal correctness and warmth that is as close to the real thing as I've heard in an amp. Because of it's sheer naturalness, it can take a while to overcome the initial impression that it is somehow soft or rolled off. That is most emphatically not the case! Dynamics are crisp and fast, and the frequency extremes are right where they need to be--not overstated or highlighted at all, just perfectly natural and realistic.

The only potential weakness of the 108 is its power rating. It flows a nice amount of juice for 100 watts, but one could theoretically run into problems with particuarly current-hungry or inefficient speakers. Part of the amp's midrange purity, I believe, is attributable to the use of the bare minimum of bipolars in the output stage. That, of course, comes at the price of power, but in this case the tradeoff is more than worth it. Just take some care in speaker matching--as you should, anyway--and you'll be rewarded with a sound that balances the very best of solid state with a midrange that will make some question whether they even need to fuss with tubes.

Despite its novel physical appearance, the need for careful speaker matching, and the fact that the US dollar has been taking a Tyson-like beating lately, the Dartzeel is a serious contender in the super-amp category. Yes, there are amps out there that do this or that "better" than the 108, but I've yet to hear one that strikes a better balance between the various areas of performance. It's a stunning piece of engineering and a landmark amplifier.

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Product Weakness: Appearance is strictly take-it-or-leave-it. Power rating requires some attention to speaker load. Cost.
Product Strengths: Naturalness, midrange magic of the highest order, speed, dynamics

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Associated Equipment for this Review:
Amplifier: Dartzeel NHB-108
Preamplifier (or None if Integrated): EMM Labs DCC2
Sources (CDP/Turntable): EMM Labs CDSD
Speakers: Von Schweikert VR-4 Jr.
Cables/Interconnects: Jena Labs Pathfinder
Music Used (Genre/Selections): Rock, blues, country, some classical
Room Size (LxWxH): 24 x 20 x 7
Room Comments/Treatments: Echo Buster, ASC
Time Period/Length of Audition: 3 months
Other (Power Conditioner etc.): Shunyata Hydra-8
Type of Audition/Review: Product Owner
hooper
CS,sorry,but I was referring to Mike's own comments,in the past,no one elses.Also,mine is soley an opinion,and entitled to be wrong,as in my opinion, is yours, in this matter.Unless the 200 page set-up guide that came with my speakers is totally wrong(I doubt it)the room absolutely affects bass,as does an amp.Ever hear of room loading?I don't care what the actual low frequency cuts off at,and am not worried about the actual lowest frequency limit.I have heard some set ups that cut off about 45hz that have "better perceived" bass than the low bass systems that you may enjoy measuring.I'd rather just listen,and get a sense of a full range sound,in itself.What I do is listen to a very wide variety of "Classical and Popular" recordings,that I know to have "convincing" low frequencies.If I get a good sense of balance,then it is "Right".Few systems really are,regardless of the measured lowest frequencies.Try putting away your fancy test equipment and use your ears a bit more,you may be able to save some potential customers some money?

If you feel the need to measure is that important,as opposed to critical listening,usually with a group of other experienced hobbyists,then knock yourself out.But,please don't condescend as to how much listening years I've had.I don't know where you got the number "45 years" from.Did you read THE DA VINCI CODE?
Cinematic Systems, you forget that Mike also has the Tenor 300 hybrids and I think Mike has had guests bring over amps to audition as well. It's hard to believe that a different amp can help add that much extra bass. Nothing I've read/heard tells me that the Tenors and Dartzeels are chumps in the bass department.

Sirspeedy, I believe the dimensions are arrived at by Rives, perhaps you should take it up with him. Honestly, I too think it makes more sense to buy speakers that fit the room rather than the other way around. Mike had a chance to build the ideal room, making sacrifices to the room just so the rest of his equipment will work better seems rather silly considering the cost of the project. From the little I know about room acoustics, I believe that a smaller dimension would at least be in some ways a compromise. It's a lot easier to change your gear than to change your room.

Like many people here and on AA, I've followed Mike's journey for a little while now. He owned his old speakers and amps for more than 2 years I believe, and other stuff a lot longer. Is that considered a fast turnaround? You're right that considering the size of his investment, I really don't think he's the type to live long with compromises. If the VR9s doesn't do it for him, I don't think he'll stick with it for long. It's not like he needs industry accomodations or whatever, so I really do believe Mike is after better reproduction of his music.
Howie: Cinematic_Systems is attempting to create controversy and be obnoxious. This is his history. He does not know what he is talking about and is not worth your time and effort.
Jonathan,

Cinematic_Systems has more experience than probably anyone I have been associated with in the past and is not "just a salesman". There is value and logic in what he states and it helps move people forward in determining where each of us want to be. Most of us we are just in search of the truth and as an engineer myself it is great to understand how things work. Not go by just what ones stated opinion is.
Cinematic Systems is not trying to stir the pot, he's basically trying to ( reasonably politely ) comment on the design of Mike's room and the selection of gear. The fact that Mike has been dealing with Jtinn as both a dealer and consultant for the selection of gear obviously brings him into the equation. Jtinn's dismissal of Cinematic's comments and observations is directly related to trying to protect his own reputation as he tries to cast aspersions on Cinematic's reputation. Since i have nothing to gain by discrediting either point of view ( i am not a dealer as the two of them are ), here's my take on the situation. As is usual, this is simply my point of view and i try to remain as honest and impartial as i know how.

The size of the room will affect nodes, low frequency extension and spl capacity. Whether or not the speaker can effectively pressurize the room has to do with surface area that it has to offer ( size and excursion capacity of the drivers ) and the "loss ratio" of the room itself as frequency varies. It is possible to have a "rigid" ( non-lossy ) room at higher frequencies, but have it act like a sponge at very low frequencies. This would introduce a non-linear frequency response into what one hears, even though the system itself may be quite "flat" outside of room contributions.

Even though the physical size of the room may support the longer wavelengths that are created at lower frequencies without creating as many nodal related problems, the construction material itself may end up absorbing those low frequencies if they aren't rigidly anchored. The air-borne low frequencies are absorbed and converted into vibration within the construction material itself, which acts as a thermal loss. This reduces both the linearity of the room itself and the spl capacity that the room can sustain at lower frequencies.

If one was running a relatively "linear" system i.e. one that measured relatively flat, it would sound "weak", "thin" or "lacking in extension" in such a room. The end result is that one would need to create a non-linear sound system i.e. bass heavy in order to compensate for the non-linear absorption losses within the room itself. The end result would be a relatively flat presentation in this room, but in any other room, the added bass would be noticeable to one degree or another. That would depend on just how lossy the second room was at low frequencies.

The same things can occur in the mid and treble region with listening areas that are over-damped i.e. the need for a "hotter" sound to compensate for all of the high frequency losses within the room itself.

Obviously, this is a very tricky area and most rooms aren't actually "done" when the initial construction is finished. That's because reality often doesn't follow theory to a "T", so additional work is required in order for form to follow function with a closer relationship. Sean
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