February 2000

Sonic Frontiers Line 3 Preamp

by Todd Warnke

Review Summary Sound "Extended and controlled" bass along with a "fully detailed" top end; "clarity of presentation" that "gives no tube shelter to harsh or brittle sources or partnering components"; mids are slightly laid-back. Features Fully loaded and then some -- including remote control, HeadRoom headphone circuitry, balanced inputs and outputs, surround-sound-processor loop, mono switch and sophisticated external power supply. Use A pleasure to use because of its generous feature set; will require close attention to partnering equipment given its neutral character. Value Not cheap, but a "full-feature preamp" that will act as the nervous system and heart of a high-end audio/video system.

Listening to music really ought to be a pleasurable experience, but as with most things audiophile, we have corrupted that which is natural. Besides comparing the size of our woofers, we also compare the itch of our hair shirts in a vain quest to define audio purity. "Tube preamps are the opiates of the weak-minded. I only use solid state as I have much better edge definition, even though the midrange is a little threadbare and brittle," brags Geek A. Geek B retorts, "Yeah, well any active preamp is a compromise. I use a passive preamp. It sounds just like your solid-state unit, but it's even more pure, if also dynamically constrained." To this Geek C responds, "Preamps? Don’t like ‘em, never have. I wire a single resistor in line with my DAC to control volume. Oh, and I never listen to the rig unless the temperature is between 68 and 74 degrees with relative humidity between 63% and 72% as anything else alters the Q of the speakers. Of course, this means I can only listen on 17 days each year. But you have to pay the price to get the sound right." While I sincerely hope this isn’t you, I bet you know a Geek A or B who aspires, perhaps secretly, to be Geek C.

From a moral perspective, it appears that we audiodweebs have a psychological need to pay a pain penalty for the pure joy that a well-configured system brings. Perhaps this is because we confuse the virtue of musical magic with a sin of sonic gluttony. Or maybe when they said "aesthetic" pleasure we heard "ascetic" and so veered in the wrong direction. Whatever the reason, the results are not a good way to attract newcomers. Just imagine the ridicule of Ferrari owners if they felt a compulsive need to drive Pacers Monday through Thursday to make up for their indulgence. Or of oenophiles if, at dinner, they had to balance Petrus with equal amounts of Thunderbird. Hardly makes sense. So what say you? Let's rise above our macho masochisms and take a close look at a product designed to offer both state-of-the-art audio performance and convenience -- like the Sonic Frontiers Line 3.

Pleasure without pain?

Preamps have undergone an evolution over the last decade or so. Fifteen years ago, every serious preamp had a phono stage simply because vinyl was the only serious medium. CD and other more recent digital media forced the line-stage-only preamp into a position of prominence, and we now refer to preamps that have a phono stage as full-function. Many if not most current serious preamps come without a phono stage, but in all other respects they often are identical to their older siblings, ignoring other changes in music and technology over the last ten years. The Line 3, as its name implies, is a line-stage preamp, but it is also at the forefront of a new type of component, the full-feature preamp.

Included in the Line 3's eight line inputs and five line outputs (two of the inputs and two of the outputs are balanced) are a tape loop and a surround-sound-processor loop. The surround loop cedes volume control to your processor, while allowing you to use the Line 3 alone and unmolested for two-channel listening. On the front of the unit is a headphone jack, and not just any headphone jack, but one that uses the HeadRoom circuitry. The four-color display is dimmable in several steps, all the way to off. There is a mute button, phase button, standby button, and an essential feature usually missing from even the finest of preamps, a mono switch.

Volume is set with a machined aluminum knob that controls a microprocessor in .5dB increments over a 191-step or 95.5dB range. Balance is set and visible in the same .5dB steps. In addition, the initial volume for each source is customizable, so, for example, you can reduce the volume of a balanced component so it more closely tracks your other sources. This last feature is the only one that cannot be set using the remote, which makes sense as it should be a set-and-forget item.

Speaking of the remote, it certainly is unusual. Shaped like a hockey puck, it is actually quite comfortable and easy to use. It is uncluttered, especially considering all the features it controls. The button layout makes sense, and several of the buttons have identifying textures (a nipple on one, indentations on others). It also has the widest range of use I’ve ever seen. Turned at an almost perfect right angle, it still works. And it works from 30 feet away as well. Finally, one thing I loved about it is that it allows for source selection, something most high-end remotes overlook. In all, except for the auto-butler and drink-refresher options, I can’t think of a single feature missing from the Line 3.

But were this about features alone, I would have to stop here and say that the Line 3 loses out to its lower-priced line mates, as both the Line 1 and Line 2 share the same features. Well, all except for perhaps one feature: sound.

Family feud

The Line 1 and Line 2 have received positive reviews since their introduction three years ago; in fact, the Line 2 is a Stereophile Class A recommendation (which leaves little room for the Line 3 in the pantheon!). Besides rankings in magazines, the Line family does have several other differences.

The Line 1 uses six 6922 tubes, as does the Line 2, but while the Line 1’s power supply is integrated on the main board, the Line 2 uses a half-size outboard power supply. The parts quality in the Line 2 is, as you’d expect, better than that in the Line 1. In fact, in many ways the Line 2 is a Line 1 with better parts and a better power supply. So the Line 3 is more of the same, right?

Right and wrong. The power supply is a full-size outboard unit that weights almost as much as the Line 1 alone and features 26 stages of regulation. The parts quality in the Line 3 shows no compromise. In fact, it could be called significantly over spec'd. So far, the same but better. It’s when you look at the tube complement that you see the change. Using ten 6922s and two 6U8As, the output stage of the Line 3 is a serious step up from that of the Line 1 and Line 2. All those tubes combine to lower the output impedance to 45 ohms single ended (90 ohms balanced), making the Line 3 truly load tolerant. Best of all, the Line 3 runs those tubes very conservatively. Sure, 12 tubes make for a very hot unit -- and a smack to wallet at replacement time -- but after five months of near 24-hours-a-day use, the tubes tested as new. That’s over 3500 hours of use! In a normal house, this could equate to many years of service between replacements.

So it’s an easy-to-use preamp, with every feature you could ask for, and it’s sturdy and stable. Still, I hear you -- all this counts for naught if it's lacking in terms of sound quality. Agreed. So let’s look at the ultimate feature.

The aural feature

The very first thing I noticed about the Line 3, as did everyone I played it for, was the bass. Here at the Warnke Winter Lodge and Musicporium, the bass was so deep and so tight that -- no hyperbole at all -- my passing fascination with adding a subwoofer to the system was entirely obviated. The opening track on Roy Hargrove’s Habana [Verve 314 537-563 2], "O My Seh Yeh," features powerful drumming, and through the Line 3, I heard every nuance. More explosive than that of any other preamp I’ve used, the bass of the Line 3 was also more extended and controlled too.

Treble, while not hot in the classic sense, is certainly not your Father’s tube treble. It has no tube attenuation, no softness, no shielding from bad recordings or poor system setup at all. On the other hand, while fully detailed at the top end, the Line 3 isn’t ruthlessly revealing either, with all the associated implications of brightness and unpleasantness with anything less than perfect recordings. Sure, as I spun disc after disc, listened to the radio or used the Line 3 in a two-channel AV setup, I was always aware of the revealing nature of the treble, but I never felt that what I was hearing was an exaggeration or distortion, so perhaps "honestly revealing," with both words carrying equal weight, is the best descriptor of the treble range.

If there is a tonal area where the Line 3 slightly misses perfection, surprisingly for a tube product, it is the mids. It’s not that the Line 3 does anything to distort the mids, but rather that the range is ever so slightly laid-back. This and this alone is what gives the Line 3 a sonic signature. Let me give you a bizarre but very applicable example. I have a friend who is an audio Dr. Frankenstein. His basement holds a custom five-way, pent-amped setup. And it works! It is coherent, dynamic and resolving. And entirely customizable. So when we swapped the Line 3 for his BAT VK-5i, we were able to tailor the sound to fit. After subbing several other preamps as well, we found that the Line 3, while not exhibiting a measurable difference using crude tools like a Radio Shack SPL meter, was the only preamp that benefited from a bump in the mids, and that doing so seemed to give a smoother response and slightly enhanced emotional reaction. Proof that the Line 3 has recessed mids? No, but close enough for me.

Dynamics, most especially large-scale, were phenomenal. What made them so was not just sheer volume swings, but the way that sudden changes of volume were just that and no more. No harshness, no collapsing soundstage, no grain, no edge, no tonal shifts. Just a sudden and emphatic change of volume. With this level of control on hand you can easily guess that a great many listening sessions were interrupted by shouts from Robin the long-suffering of, "Turn that thing down!" And from the look on her face, it appears that many calls were also drowned out.

Staging, as you can piece together from the previous paragraph, was incredibly stable. Dynamic swings had no effect, with instruments neither congealing nor ballooning with volume increases. The stage showed superb right-to-left spread and even better depth. Discs like the 1995 Telarc release of Arvo Pärt’s Fratres [CD-80387], which was recorded in a Belgian monastery, were an incredible joy to listen to as all the hall information was accurately delivered.

Clarity of presentation is also a hallmark of the Line 3. Noticeable, especially when swapping quickly, the Line 3 offered a far clearer view than my reference BAT VK-3i. For example, on the Fratres disc, the percussion that begins the first track is located about 30 feet back from the mike. While not cloudy with the BAT, the Line 3 presents the players with not just greater detail, but in a hall that had a good cleaning. And with the added clarity also comes greater detail. While no new worlds were opened up (the rest of the system and the previous preamps I’ve had through here are superb after all), the subtle increases showed up as added texture to instrumental solos and greater definition between instruments in orchestral settings.

Are you alone in there?

Does the Line 3 have any competition? Certainly. In many ways it reminds me of the Joule-Electra LA-100 Mk III I reviewed in the summer of 1998 in that both have remarkable clarity, detailing and dynamics. Yet there are differences, both objective and subjective.

From the objective view point, the Line 3 offers many more features than the LA-100: more inputs and outputs, balanced connections, a headphone amplifier, a remote with more controls, a better display. The Line 3, because of its unparalleled clarity, also gives less latitude for system or recording flaws. Such honestly revealing sound can be a brutal honesty at times. And while the Joule Electra preamp is not a forgiving product, it does seem to offer just a bit more room to recordings and equipment.

Elsewhere, the Line 3 offers slightly better dynamics and deeper bass, while the Joule Electra has better mids and a greater emotional impact. When the Joule resided here, I was constantly sucked into every recording. With the Line 3, when everything clicked, I found it impossible to walk away from the system. But when the recording was a bit off, or my day had been especially poor, the Line 3 was less able to alter my mood. This is very subjective for sure, but then SoundStage! is not Stereo Review, or whatever the late Julian Hirsh’s magazine is called today.

Which of these two world-class preamps is best is truly an individual call. They offer many of the same skills, but to slightly different ends. The Line 3 emphasizes neutrality over everything, and couples this with flexibility and features, while the Joule Electra preamp proffers a more involving and very slightly smoother view, whilst remaining essentially neutral. This is a tough choice, and a very individual one as well.

Parting gifts

At the end of the day, the Line 3 offers incredible, almost impossibly neutral sound. It also offers convenience and flexibility without compromising that neutrality. In many ways it is a Ferrari for weekday use, a Petrus that blends with hamburger as well as Filet. And all this comes at an affordable price considering the Line 3's statement skills. Yes it still has a flavor, as no product is flawless, but nonetheless it retains state-of-the-art neutrality and transparency, dynamics, bass extension and slam, staging, and detail retrieval. The flaws, even if they aren’t gross enough to deserve such strong of a tag, are mids that are slightly withdrawn, a slight reticence to open to the soul of a recording and the fact that it gives no tube shelter to harsh or brittle sources or partnering components (and these last two items are so subjective that many will disagree that they are potential flaws). Taken together, this all makes the Line 3 the most neutral product I’ve ever had pass though here.

...Todd Warnke
todd@soundstage.com

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