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

Showing 19 responses by cinematic_systems

Don't have to be sorry, but I really felt in my experience with the cables that they would bloat the sound of your system and round it off. I have no knowledge of the Dartzeel and that maybe the wild card in our differing opinions/experiences.

Clearly they are working for you, and that's good.

My observations were made with the speaker cables FWIW.
Hooper,

Who helped design your system? Its very unusual in conception.

What other amplifiers did you try in your system?

Jena Labs has always smeared the sound in my system how does it work in yours, I would think it would round the sound off too much to sound detailed on a speaker like the VR4jr. What do you think.
$35,000 in electronics and $4,000 speakers, is very odd, but I see you've struck a balance with the VR9's. Atleast with the cost.

Its too bad the Jena Labs is the best you ever heard a $400 set of Analysis Plus would do wonders from where you are. Having heard the Jena's on two very different systems their signature is clear. Smudge, Hey, I understand where you're coming from now so I'll stop interupting the regularly scheduled commercial.

I appreciate the objective review.

J Tinn,

Smearing the leading edge, it's an old cable tactic, perfect for overly bright edgy audiophile systems. Literally removed the leading edge from the sound on the first system listed below.

Modified Magneplaner 20.1's (you know the one)

and Aerial 20T's with a Spectral system. Fixed this one right away with Cardas Quadlink.

Hey that's what they do! Maybe your systems aren't up to the task or you like that sort of thing? What do you think? Fact is my little system would easily show the Jena's built in effect, because they are transient perfect and phase correct. Spending more does not cover the defect or make it a positive.

I don't have a "problem" with Jena, Jena has a distinctive "sound" I do find problematic on quality speaker systems but actually it could have its applications on ill balanced systems. Especially underpowered ones where the amp clips a good deal.

If you have proof they don't smear the leading edge i'll recant my statements and apologize. Just your word against mine I suspect.

I do have 5 witnesses that sat right next to me and concurred about the obvious effect, would you like to hear from them? You know some of them.

Thanks for the sermon be aware your elitism does not intimidate me, and I would be more careful about how you swing it around in my presence.
Howie you don't have to sit in the sweet spot to hear it, it a very obvious coloration of the sound.

2 people sat next to me when we listened to the Maggies and 4 of us were present when the 20T system was being used and in both cases people took their turn in "the" chair. The effect was quite obvious most people didn't sit in "the" sweet spot to confirm the change they sat there to see if they liked it better.

As for my system let's not forget, my little system is my bedroom system and don't kid yourself about its quality. Those speakers would be about $4000 retail and now that I have my D2 Audio amps are on the way should make for a very nice system.

Keep in mind the Behringer can be replaced by a BSS or a Lake Technology crossover at my discretion.

Alas,

Forgive me for this oversite; I should have included this reviewers comments to have some back up.

From the Rick Gardner Positive Feedback review;

"Intellectual confusion aside, I will tell you what I hear. I think a lot of upper midrange/lower treble energy in digital reproduction comes out as "noise" because of time coherency problems. We call this "tizz" and we all abhor it, while assuming it is just part and parcel of the current digital standards. Well, that may not entirely be the case. Imagine wires that can
sort the tizz and upper midrange crunchies into something very much like music. Think about all of the hard, tizzy, overly sibilant digital recordings you have (especially the ones where you love the music and hate the recording). Now, think about those recordings transformed into something that is not only survivable, but also actually rewarding."

Is the digital recording over-sibilant or has he discovered his wires are over-sibilant? See if the recording remains over sibilant then the JL wires are filters are they not? The key word in that whole paragraph is "sort" and up till now dim wit Rick has tolerated "tizz" on his digital, come on!

BTW Ricks system is horrendous, a disasterous composition of "supposed to be good" products.

Rick Gardner continues....
"The simplest, coherent description I can give is "buttery." I am using this term to suggest the liquidity and harmonic richness of single-ended tube amplification, without the artificial sweetness and weird tonal shifts. Utterly seductive."

Ever touch butter? what happens? Smudges doesn't it. There is definitely two sides to the coin for a filter and I'm thinking the last thing a VR9 needs is to be buttered up. But since Its not my system its not for me to say.

"Jennifer's wires have driven me deeper into my large CD collection than I have been for some time. Recordings I had decided were simply digital disasters I now find enjoyable."

Cable system that fixes recordings that are "digital disasters".

What if the recording isn't a digital disaster? Then what information is being scraped off or changed? I'm just asking because you can't turn the cable off!

I'm a dealer and a consumer and I'm calling it like I've heard it and apparently as Rick has heard it. His system needed the Jena Labs treatment and the two systems I have heard did not. What say you about yours? My original comment about Hoopers system was a hunch about his system and it didn't look like it would benefit from being "buttered". Maybe the Dartzeel is bright?

Have a good one guys.
Howie,

Midi Exquisites can rock, you just need to run them with the right amplifiers. My friend Bob played Creed and Bowie and Elvis Costello with absolute clarity and impressive drive at 110dB at the seating position. The lack of distortion in the system is phenomenal and I could see how that speakers lack of strain and distortion could make it seem flat or undynamic sounding. Its disconcerting when a speaker is such a faithful transducer like the Midi.

Adding a sub made Bob's Midi's capable of 110dB+ playback at the seating position without strain or compression. Only the Meyer X-10 could exceed the Kharma/ATC sub combo in the impact and dynamics. They passed the Megadeth test with flying colors. Something many, many, many speakers cannot do. Its rare a speaker with such a refined pedigree can get nasty without losing its composure.

In the end I was very surprised at Hooper's comments too. I don't think the amplifiers he tried were up to the task. I know the Dartzeels have too little power to be effective, but I'm surprised the Tenors with 600 watts couldn't wrench some heartbeat out of the Midi's. But if they are mellow then the Midi's may never have seemed loud?
Hello Mike,

So the Dart is equal to the Halcro and Levinson on the Midi Exquisites dynamically? How about the Tenors?

Why does your room suck out the frequencies below 30hz? You should be getting into room gain areas there. Did they over-damp your room at those frequencies?

Jafox---in Hooper's expansion to your request he made some statements that Howie and I thought were surprising. You see this still has a great deal to do with how the Dartzeel sounds in the end. And as you can see Mike Lavigne disagrees with Hooper and myself. And since Mike has Midi Exquisites he would know, although the lack of bass is something I suspected would be a problem do to the modest power ratings on the Dartzeel still.

Your CAT amplifiers are like the Levinson 100 watt No. 20 mono's. 100 watt amplifiers that can weld. According to Dartzeel this amplifier does not possess a power supply capable of extraordinary current, rated at a paltry 160 watts it is not a high current amplifier which is how it likely gets its unique sound.

The fact that one speaker sounds "lifeless" and suddenly another one comes to life has a lot to do with the amplifiers in my experience. The amplifier is the motor in the speaker amp circuit system.

Despite my reserving my "system" to my budget bedroom DIY system, my ATC/Meridian system gives little if anything away on performance to any of these systems listed. So I am interested in the performance of these components. I am also completely shocked at how the Tenors and Kharmas have not been able to withstand the onslaught of VonSchweikert? and Dartzeel? It is an option of mine to become a VSR dealer, so I am very interested in this thread in many facets. VR4 HSE more dynamic than a Kharma MIDI Exquisite, better suited to judge the amplifiers he was comparing? Ouchie, on the Kharma's? or the Dartzeel and Tenor? Bad amps?, bad speakers?

How good can the Kharma's and Tenor's be in the first place if they can just be replaced universally one after another despite the presence of persoanl taste or subjectivity?
Well then I guess we have a disparity of experiences;

Hooper a composite of equipment owners opinion makes anything you say as valid and important as anyone's and requires no qualification except that's how you felt, and the more we know about your decisions and room and equipment the more we can relate what you say to our own preferences. If you feel we had a semantic disconnect then Its important to clarify and get a composite of others experiences. Your opinion matters as does ML's etc. We now are getting a better picture.

The Kharma's do not have the jump factor because they do not distort the leading edge and it is insult and fabrication to say that a Midi exquisite cannot handle a lowly 110dB , Gladstone had his jazz going at 104-105dB average at 15 feet...that's 5M...113.8dB @ 1M! and if you didn't measure it you wouldn't have known it was that loud. Adding a subwoofer to the Midi Exquisites will allow them to play even louder and give them the same dynamic capability as the VR9's. The only difference between the VR9's and the Kharma's is the subwoofer, which greatly increases the VSR's output capability as it would the Kharma.
Can I accept that "Jtinn" actually posted the message on 4-01-05 or was that an April fools joke somebody pulled?

He's not really that shameless?
"We also were surprised,since you seemed to love the Ex Ref,that you didn't build a slightly smaller room to allow those speakers to pressurize it better."

Just so it is clear JTinn's description of how Mike's room interacts with the Kharma Speakers and the bass has nothing to do with the Kharma's ability to produce bass, nor is it remotely correct. Infact if 25hz cannot pressurize the room how can smaller wavelengths pressurize the room? You would think someone with 45 years experience would understand basic room acoustics.

His bass problem currently has to do with his amplification choices and the fact that to make a room the size of Mike's room flat in the bass something has to be done with the lowest frequencies. After seeing the specs on the Dartzeel it is not a good match for the Kharma's for making bass. And the perceived dynamics likely has something to do with the overshoot that creeps up in the square wave as the amplifier is pressed, which explains why JA only measured the square wave at 55 watts. To drive those small Etons effectively more power is needed.
Mike,

I appreciate the clarification, JTinn stated quite clearly that your room did not suck out or better word (I should have used originally) attenuate the frequencies below 30hz and clearly it does. And based on your demands it should, to offset room gain. So based on JTinns comments on your room, I could not understand why you couldn't get any bass.

I'm trying to understand but I keep getting conflicting reports back and forth and although I believe everyone's experience to be valid I am trying to correlate semantics and such. I can not find anechoic measurements of the Midi exquisites, are they on the web?, because low frequency measurements are hard to do, and the ones I measured had a slight shallow dip from 40 to 25 hertz where there was a bit of a peak at 25hz. But unless I took the speakers outside I can't really trust my bass measurements and seperate the room from the speaker. I'd be real interested in the anechoic measurements since my client will be moving his midi's to a new room. Can he get them from Kharma?

Howie;

If you read the thread carefully you will see a great deal of conflict or contrary information. This why I keep asking.

Sirspeedy,

LOL, hey you are free to guess at it if you like, but my clients don't pay me for perception, they pay me for the real thing. You and your buddies can kid yourself all you like about how well you hear and how its good to just walk away with a memory. I walk away with documentation.

Critical Listening is the easy part, anybody can do it.

Thks Sean and Stenrsr
Howie,

First of all I am not in the music business, I am in the music reproduction business. I design speakers and music playback systems.

I am not applying science to music I am applying science to music reproduction. And because I care a great deal that the artist intentions are preserved I'm not so arrogant to believe that what I think feels right is good enough! A conductor once told me that " the creative process stops when the CD is caste. Your equipment can not make my performance better it cannot interpret the music...if you're lucky you might actually hear what I intended but that's only if the system is good enough and you're educated enough."

Your argument does not apply to me and is simply a way to elevate yourself into the creative process. As if selecting the correct component somehow makes you enlightened and that a "musical" system is some magical beast that only the "enlightened" can appreciate and own. Can we not measure the beast? In your mind no...because it is your fantasy and not a reality. A Unicorn

Some how my methodology seems to offend the "enlightened" because it scrutinizes their decisions and holds them to a standard that they are offended to be measured against. And I'm not implicating anyone in particular, this has just been my experience. And being held to a standard is problem for those who are too intellectually lazy to attempt some personal education to actually grasp the technical strings that helps them tie them to the recorded performance. No trial and error is the methodology of choice for the "enlightened". They engage in alchemy and consult wisemen for guidance and yet they may have been to the promised land yet weren't educated enough to know they were there. And no measurements left behind to help them find their way back if they realized they've gone to far.

Your Bill Evans example only proves my point, critical listening can be done by anyone. Its the easy part. Its easier to have an opinion than it is to be educated on the subject. The subject being music reproduction.

Interesting Mike,

Yeah I'm trying to get my ducks in a row, I was definitely turned around about which speaker you were talking about.

The Midi Exquisites should give you some bass extension, I suspect that the effort made to keep your room flat will work against a speaker designed to work in a "normal" room. You have a falloff where a normal room would have gain.

That 80hz suckout probably was minimized due to the 2 woofers per speaker being in different locations. The single woofer on your 1B's would give you a more focused dips about the room.

The Dartzeels won't be a problem on the VSR's for obvious reasons but I suspect they are struggling in your environment, due to the complex impedances of the speaker and the room. In room the Midi Exquisites seem a bit boomy to me. And should give you some sense of extension. But the impedance of the Kharma in the bass could be below three ohms and swing to 70, The Dart doesn't have the current to get on top of that."

Midi's rating by Kharma as down to 22hz and the 1D's rating as down to 25hz this doesn't compute. my conclusion is that the 1D only truely goes to around 30hz in a typical room......"

Depending on the bass loading of the port can rolloff very steeply and bass can disappear very quickly and maybe even sound a bit stunted. The Midi seems to have a true 4th order port which gives a more gradual decay of the bass, infact the port seems tuned very low as to create a shallower bass rollof, which is why there is a slight dip in room from 40 to 25.

Thanks for the response.
JTinn,

I think think these three ditti's says it all about you and your philosophy.

NUMERO UNO!!!!!!!!!!!!!

"How many times do we read a review where the measurements were poor but the reviewer loved the product, or the measurements were outstanding and the sound was not to the liking of the reviewer?

So I'm supposed to believe Rick Gardner who's entire equipment review history is equipment he bought from you?
I'll take the measurements, thank you very much!

Numero Dos; As a matter of fact, he has been described to me as a complete lunatic.

This lunatic fixed his system for free (clearly proof that i'm crazy), how much more equipment and cables would you have sold him before you would have said I think something's wrong with your system? Sometimes the truth is bad news for a client and people who post here.

Numero Tres;

"To imagine that a cable capable of extending from DC out to beyond 30 Mhz could smear frequencies that low in the bandwidth is ludicrous. The cables "measure" brilliantly."

First of all you make an assumption and you'd be wrong and just because they measure well doesn't mean they sound good. How many times has a reviewer said something that measures great sounds not so good? I know what I heard and that's what really matters not some measurement.

Now do you see how stupid that sounds when it comes from my keyboard?

Later.
Howie,

We're on the same page just different sides, you are the artist looking at the process from the beginning, I'm the technician looking at the end of the process back. We are both leaning on our strengths and the areas we have developed the most.

We need each other, because your main focus is performance, mine is preservation of that performance. Without your perspective I cannot know the intentions of the artist, without me the intentions may be obscured.

I like you do not discount the importance of knowing (educated) music as well as knowing (educated) sound. Unfortunately they are two different things. I am not a musician but I can read music, but not as well as I can read a spectral decay plot.

As for "elevate", I was not implicating anyone specifically but from an objective stand point do I suit myself(inserting myself in the production) with the system I design or do I suit the artist (pursue absolute sound).

Since a perfect system may not exist, the line is blurred a bit.

Maybe I read Ayn Rand at too young an age? :)

But we are not in any disagreement, and my reaction was to the implication that I measure at the expense of listening. That is not the case. I listen, then record that experience with a snap shot of the performance of that system. A permanent record to compile with many many other experiences. Its not a complete record but its better than nothing. Like photo's from a vacation.

Believe it or not my degree is in film making, I am creative type with a technical curiosity and aptitude.
"Cinematic systems,let's just say that my "Buddies" really don't "guess" at anything.They are skilled and experienced hobbyists that have been at this longer than you,or myself,most likely.I believe that they would find your condescending comments humorous,as we are pretty adamant about how sensitive the "average" ear becomes,once you have been at this hobby awhile."

Yeah I know. I think pretty much everybody has mentioned that to me at one time or another.

" wide variety of "known" program material",

What exactly do you know about it? Can you tell me what Microphone/preamps/board/Mastering etc. What is your reference speaker, the one used by the studio? The only thing you know is that it sounds good to you, but what is that exactly? You have Avalons right? Why? Why did you buy them over all the other options? What makes them special, try to answer that question using a vocabulary that would allow me to apply it to my situation. Musical, accurate, revealing are not helpful.
Howie, Thank you for your help in expressing one of the quintessential obstacles to allowing this hobby to move forward.

"Where did I give you the impression that I was trying to "elevate" myself into the creative process?"

"Musicians doesn't NEED anybody really."

"So even if I have the most inaccurate equipment, it wouldn't even matter. It brings happiness to one person: me."

Let me post this again so everyone understands the context.

"from an objective stand point do I suit myself(inserting myself in the production) with the system I design or do I suit the artist (pursue absolute sound)."


I guess the word is that I went over the top in response to your post but I was responding to what you were really going to say. Notice how you "elevated" this conversation up and out of my context and out of the context of this forum. Your attempt to make me irrelevant and belittle me. Good thing we're not playing chess?

See many people who would criticize me for being harsh with you didn't realize where you were going. You were going here. If you're not a musician you're irrelevant and even if we don't know what were doing. LOL! Gotta love "jazz".

Howie continues;

"I don't mean to be ignorant but to say musicians NEED people like you is pushing it IMO."

See this would be the arrogance I spoke of, not ignorance.

This is where you "elevate" yourself above the objective constraints of this conversation to persuade me that you're "enlightened" and I am not. How could a thug like me understand, its true for me it was football or music as a child and unfortunately I was instantly good at football, so it was the choice I made. So now I can hack away at the keyboard, but I'm slowly im proving.
Mes,

LOL!!!! What part of this thread wasn't transparent from the start? LOL!!!!!

My only question is how many times did JTinn call you before you had to post? 4-5? I've got a pool going let us know.

Mes, howie, hooper, any other JTinn buddies want to pile on? I'm bored with this thread. Just alot of whining and cliche slinging going on. I really didn't believe this whole "syndicate" thing but its true. Sorry I doubted those who had informed me. I had to see for myself....LOL!!! this has been great!

Howie; Musicians don't need me if they want to play with themselves. this is true and if they don't care how their music sounds in people's homes. Happy now I said it?

Bye Jonny, been fun. See you in NY.