MBL 6010 D preamplifier Page 2

The review sample included the balanced-input and MC-only phono-preamp modules, which brought its total price to a breathtaking $26,490. Yes, the 6010 D is a beautifully finished, well-built, full-function preamplifier in a large, heavy chassis, and MBL cites for it some eye-popping specs—but could its sonic performance possibly justify the price?

Using the 6010 D
I suspect that few audiophiles will use the 6010 D's second set of outputs to route their signals to another room, but if you're one of them, you'll welcome MBL's dual system. Everyone else will pay for a feature they don't need, and that makes them scroll through two of each input to find the one they want to hear.

The input section uses "level encoders" that provide up to 12dB of attenuation, while the final output level also features 12dB of attenuation, using "super-fast analog ICs (integrated circuits)." If you've got sources with widely varying output levels, the level-trim feature will come in handy; otherwise, it and the second, global level and balance trim pots just before the output might have you worrying about just how many barriers MBL has erected between the preamp's inputs and output, and exactly how they're implemented. The product description doesn't make that especially clear, due in part to poor translation from the German.

The supplied, non-illuminated remote control can operate a number of MBL products. Housed in a precision-milled block of satiny aluminum, it has symmetrically arranged rows of small, circular buttons that aren't all that well identified. The learning curve isn't steep, but the poor ergonomics require you to look at what you're doing before pushing a button. If you listen in the dark, keep a flashlight handy.

Should a preamplifier "sound"?
In the mythical land of perfect recordings and utterly neutral playback gear, no preamplifier has a "sound." Neither do amps or speakers or phono cartridges. But in the real world we live in, every sound recording is a flawed replica of a live or imagined event reproduced by equally flawed playback gear. Most tube preamps enrich harmonics and provide a sense of continuousness, produced in part by their superior characteristics of sustain and decay. Although the less desirable tube preamps can sometimes still sound good, in my opinion they produce euphonic colorations that are difficult to ignore, and have high noise floors and sluggish rhythmic performance. Most solid-state preamps offer faster attack, greater transparency, and better resolution of inner detail, in part because of their lower noise floors and higher signal/noise ratios. But the less desirable transistor preamps sound clinical, producing unnaturally fast transients that sound too sharp and "etched," as well as bleached harmonics, truncated sustain, and limited decay.

Over the past decade or so, while the performances of the best solid-state and tube preamps have yet to meet on some common aural ground, the differences between them have become smaller and fewer, making a choice of one over the other that much more difficult. Tubes still rule when it comes to sustain, decay, and harmonic development, but solid-state still holds the edge in transient attack, transparency, and resolution of low-level detail. You can't have it all in a single technology, evidently, and depending on your musical tastes, you may not want to. On a recent trip to California, I sat mesmerized, listening to a tube-and-horn-speaker system that, while producing obvious colorations, made jazz recordings sound so convincingly alive that I could have listened to it all night. But had I put on a rock or a classical recording, I don't think I'd have lasted 10 minutes.

How did the 6010 D "sound"?
The 6010 D's three level controls did not create a deficit of transparency or detail, nor did they add audible noise. The MBL sounded very quiet, transparent, and dynamic—perhaps the quietest, most pristine-sounding preamp I've heard. It did a commendable job of resolving subtle, low-level microdynamic shifts, and it let flow the big macrodynamic gestures that help make good recordings approach the sound of live music. Its transient attacks were fast and clean without being so sharp or etched as to overwhelm the sustain. And the 6010 D's superbly low noise floor let the decays of the sounds of musical instruments convincingly develop and fade. The very best tube preamps better flesh out the sustain and decay, but they don't quite measure up in the attack department.

The 6010 D's reproduction of space and imaging, while no match for some of the better tube preamps for sheer physicality and three-dimensionality, was generous and solid. Soundstage depth and width were good, though they weren't among the MBL's stronger suits. The solid-state darTZeel NHB-18NS I reviewed in June 2007 does a better job of this, producing greater image dimensionality and soundstage width, and particularly depth, while also being able to bring the front of the stage well in front of the speakers themselves, when appropriate. The 6010 D kept the sound closer to the plane described by the speakers' baffles.

Despite a frequency response that MBL claims begins at "DC," the 6010 D's tonal balance was a bit lean in the bottom octaves. But still, as described above, its clean, fast attacks produced taut, superbly detailed bass. This quality improved the bass of overripe recordings, but exacerbated it on the leaner ones. With reference-quality CDs and LPs such as Davy Spillane's oft-cited Atlantic Bridge (LP, Tara 3019), the bottom end was somewhat less well developed and generous than I'd prefer, but that was in my system. Nat King Cole's Love Is the Thing (LP, DCC Compact Classics LPZ-2029)—which sorely needs to be in print again—corroborated the sense I'd gotten of the 6010 D's less-than-generous development of the lower midbass. Cole's voice, while brilliantly reproduced in the middle region of the audioband, was a bit shy of the requisite velvety warmth on bottom.

The 6010 D's midrange, while not as tactile as that of a great tube preamp, was generous and particularly well textured. Over the long haul I found the MBL's upper octaves somewhat brighter than I like, though this was mostly compensated for by its cleanness and correctness of attack and its airy, effortless HF extension. The audible differences between the direct- and capacitor-coupled inputs were minor and of little consequence in terms of audible frequency response, but the 6010 D's overall direct-coupled HF performance might have sounded a bit cleaner and purer than the capacitor-coupled variety. I wouldn't want to be tested blindfolded for that difference, but I think the 6010 D's unlimited HF extension and airy, extended upper octaves would be easily identified in a blind test pitting it against other preamps of more conventional bandwidth limitations. The 6010 D let it all through—including, perhaps, HF detritus you might not want to hear from many recordings.

Overall, the 6010 D's bottom end was less than fully fleshed out, and its top end was slightly aggressive but airy, clean, and well extended. While not at all harsh, this tonal balance sounded somewhat lean and analytical when driving the Musical Fidelity kWs or the warmer, richer Luxman M-800A class-A power amplifiers (single-ended or balanced), currently under review.

MC phono module
The 6010 D's moving-coil phono-stage module ($2020) has a generous claimed overload margin capable of accommodating a wide range of low-output MC cartridges and is adjustable from 2000 ohms down to 10 ohms; it was set to 100 ohms as reviewed. No doubt you can get a higher level of performance from many of the better outboard MC phono stages than the MBL provided, and certainly with far more flexibility of configuration. But, like darTZeel's latest built-in stage, the MBL's sonic performance was credible, and roughly commensurate with that of the preamp's line-level circuitry. In terms of dynamics, image compactness, overall transparency, resolution of detail, and just plain slam, the MBL module was no match for Naim's SuperCap and SuperLine—but the Naim combo sells for around $10,000. At the MBL phono stage's price of $2020, and thanks in no small degree to working off the 6010 D's excellent power supply, this option is a bargain, especially for the vinyl neophyte or someone just getting back into LPs. It combined a high level of transparency and smooth tonal balance with good dynamics, and it was superquiet. Imaging was somewhat diffuse and larger than life compared to the best outboard phono stages, but consider the price difference! Just make sure your cartridge is compatible.

I used the MBL 6010 D every day for several months. It proved to be a reliable, easy-to-use preamplifier that, once broken in, maintained a high level of consistently impressive sonic performance, especially in its exceptional high-frequency extension. The remote control made selecting inputs and changing the volume easy and precise. The two sets of outputs proved one too many for my system, but you might need them; if you do, the 6010 D offers a good solution. The same is true if you need a processor pass-through to seamlessly integrate the 6010 D into a multichannel home theater.

Based on how well other MBL components have fared on John Atkinson's test bench, I'd be very surprised if the 6010 D didn't exhibit ultralow noise, vanishingly low levels of distortion, and an ultra-wideband frequency response that's close to ruler-flat. As I recall, that's how darTZeel's battery-powered NHB-18S measured, at least via its single-ended inputs and outputs—yet these two preamplifiers produce very different if equally impressive sounds. I find that the NHB-18S sounds less mechanical, less clinical than the 6010 D, while being equally resolving and transparent. While it's possible that the MBL comes closer than the darTZeel (and many other preamps) to that elusive, oft-cited goal of a "straight wire with gain," my ears so much prefer the $29,000 darTZeel that I recently bought one.

Why the preference? Perhaps the NHB-18S has a purer signal path, with fewer junctions. It certainly has a more advanced system of controlling volume, integrated into a more recently developed circuit, all of it entirely out of the signal path. And no doubt my choice is at least partly system-dependent.

But the darTZeel and the MBL both live in the same tony neighborhood; I wouldn't consider buying one without first having heard the other.

MBL Akustikgeräte GmbH & Co.
US distributor: MBL North America, Inc.
263 West End Avenue, Suite 2F
New York, NY 10023
(212) 724-4870