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
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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sirspeedy, as Howie mentioned.....i am not one to change gear willy-nilly. i had owned to Exquisite's for almost 4 years.....and had no particular desire to change until the new room came along and gave me a reason. i've had the same cables for 4 years, the same passive pre for 3 years, and other aspects of my system are pretty stable too. the reason for building the room is that i realized the limitation of gear......after i had tweaked and tweaked over a few years to wring all i could from my gear and previous room.

we agree on the 'art' aspect of the Kharma.....yet.....it's simply not the issue. aesthetics are obviously important to me; but not at the expense of performance. a few years back i switched from the Linn CD-12 to the emmlabs......from beauty to the beast.....but the beast was better. and over the last three years my decision to switch to the emmlabs has proven correct FOR ME. there have only been 4 sets of VR9's made so far and there is limited exposure of the product.....i am not looking to make a popular decision......i want the right product for my situation.

i do have one question; where do you come up with my 'Rock Music Tastes'? my personal viewpoint is about exactly opposite and has been stated numerous times. i would never want what i refer to as 'one-note bass' or 'rock-show bass'. i would take the bass performance of the Exqusisite's in my current room 1000 times before i would want boomy bass energy for the sake of itself. bass performance needs to serve the music.....and never be an end to itself or prominent. my perception of the VR9 is consistent with that viewpoint and if that proves to be untrue when i have them in my room i will go another direction. in fact, the main reason i did not go for a separate subwoofer with the Exquisites was my fear of incoherence and boomyness in the bass.

i asked my designer to design the best room he could; and not the best room for the Exquisites. i knew the Exquisites did not have the deepest bass extention and the most visceral dynamic performance......i didn't know how they would actually work but i wasn't surprised by what happened.

Cinematic Systems; i must disagree with your opinion that different amps might make huge differences in my bass extention. the truth is that the anachoic bass performance of the Exquisites is not too different than what i get in my room. the rear port just can't do enough in my room to support the 40hz to high 20hz range that it will do in most rooms. this is a speaker/room issue, not an SPL issue. it was down over 15 db from 20hz to almost 40hz.....so another amp is NOT the issue. another amp may add a sense of weight or presence, but it won't measure differently......and would come with unacceptable trade-offs. it is POSSIBLE that i am wrong here......but not too likely.

i have had many amps in my previous room (maybe 20 SOTA amps) and i never had one that seemed to significantly effect bass EXTENTION. they might allow better control, better articulation, or a sense of foundation......but they won't make 40hz extention.....22hz extention.

the Tenor 300 monos have lots of bass control and were equal to many high powered amps when i had them in my previous room. these were the amps my new room was measured with.
I'm sorry if I seemed defensive at any point in any thread.Mike,I truly wish you the absolute best.You should do as you please,afterall who am I to judge anyone,as I've gone through the merry-go-round quite a bit in the past,and I've never even been in your room.My intent was more like the kind of advice I'd give my son,in order for him to save some money,on something.I only opened my big mouth because I obviously loved your component choices,and questioned alternatives to allow such fine equip. to stay with you.Best of luck,though you won't need any!!

PS: You showed real class by not commenting,as I was trying to bait you a bit(though in a friendly way).I doubt if I could have risen to that level.
thanks sirspeedy for the good wishes. the attention (good and bad) my postings attract is of my own doing. if i don't want the feedback i should just keep to myself. mostly i enjoy the discussions and relationships that result from my choice to share my experiences. many directions i have eventually gone have resulted from advice i initially rejected......i try to stay open-minded to any possibilities.

since this is all just fun for me anyway.....i typically don't get too riled over any comments.....i leave that sentiment for business.

best wishes to you too.