VTL TL-7.5 Series III Reference Line Preamplifier

Bringing Home the Concert Hall

Equipment report
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Solid-state preamplifiers
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Products:
VTL TL-7.5 Series III Reference Line
VTL TL-7.5 Series III Reference Line Preamplifier

The Boston Symphony Orchestra evokes warm memories for me. In high school I spent a summer at the Tanglewood music camp in the Berkshires, where I got to study with the Empire Brass Quintet. One of the bonuses was that I received a pass to attend the concerts put on by the Boston Symphony in the evenings. A quick stroll up the road, a seat in the immense shed or a spot on the lawn, and I could enjoy an excellent concert. So I was excited when I had a fresh opportunity this November to listen to the Boston Symphony in its large hall, which was modeled on Vienna’s superb Musikverein, located in the center of the city. A highlight was hearing the BSO perform excerpts from Richard Wagner’s Die Meistersinger, which featured both chorus and the legendary bass James Morris. The clarity of the triangle, the tintinnabulary effects of the glockenspiel, the sonority of the trombones, the sheen of the violins, and the stentorian robustness of Morris’ voice—all were riveting. But perhaps the most tremendous part arrived when, after a moment of silence, the entire chorus thunders, “Awaken!” If anyone was snoozing at that point, he certainly did jump to attention. In fact, the audience was transfixed by the blast of sound washing over it. “If the hairs on the back of your neck don’t stand up after that,” a good friend remarked to me, “then there’s something wrong with you.”

Can a stereo system duplicate that sensation? Maybe it’s an unfair question, but the closest I have come recently has been with the new VTL TL-7.5 Series III preamplifier. The TL-7.5 preamplifier has always been a solid performer, but its new incarnation is far and away the best preamplifier that VTL has ever produced. It simply sounds as though a barrier to the sound has been removed—the sonic equivalent of watching a sluice gate rise and water rush through. Perhaps I should not have been entirely surprised. Last year at the Rocky Mountain Audio Fest, the VTL room featured some of the best sound at the show. VTL was introducing both its new TL-7.5 Series 3 preamplifier and its revised 450 Series III Signature monoblock amplifiers. The sound was visceral, fast, and explosive. The Wilson Sashas performed as well as I have ever heard them (though Peter McGrath’s excellent recordings do, as my friend and TAS colleague Jonathan Valin has pointed out, give any demo he is associated with a leg up). The demonstration piqued my interest in reviewing the TL-7.5 preamplifier, whose earlier iteration I had experienced a few years earlier together with VTL’s Siegfried monoblocks.

For many years, VTL has been known for its amplifiers. Wotan. Siegfried. Those are the kinds of names that VTL has bestowed upon its prodigiously powerful tubed amplifiers. (Wotan more than lives up to its name by outputting a hefty 1250 watts or so, and I suspect that the company may, in the future, create a successor that will leave most competitors gasping, at least in the power department.) When it comes to preamps, however, VTL has perhaps not garnered quite as much attention. That may begin to change. The revised TL-7.5 reflects both a wealth of technological changes and a serious effort to refine its sound. VTL has hewed to its clever “clean box and dirty box” approach in constructing the preamp. The preamp is a two-chassis unit; the first is called a control chassis and contains noisy circuitry; the other is the audio chassis, which uses a set of 12AU7 tubes for gain. The point of using two boxes is to isolate the audio circuit from power-supply noise. The solid-state power supply employs what VTL calls precision regulation to banish AC noise from the audio signal itself. In seeking to improve performance, VTL concluded that tube power supplies sounded better than the MOSFET-based one that it had been using in earlier iterations of the preamplifier. I have always found tubed power supplies to sound more blissful and organic than their solid- state counterparts. But VTL decided to up the ante by replacing the MOSFETS in the buffer stage with a JFET that had been developed for use in green technologies.

What, exactly, is this new and mysterious JFET? VTL ain’t saying. It seems to regard this device as its version of the ULTRA project that Great Britain used to crack top-secret German military codes during World War II. Indeed, when I asked VTL’s Luke Manley directly about its provenance, he just chuckled. “Need to know basis,” was the phrase that came to mind. But the device itself appears to have significantly improved the performance of the preamp, endowing it with more speed and slam. And what about Teflon capacitors, which have come on strong in recent years? VTL is using them as bypass capacitors in the power supply, but not in the audio signal path. Manley told me that he believes that they can impart too hard a sound and create “an overblown soundstage, with high listener fatigue.” One thing is clear: The TL-7.5 appears able to drive almost any impedance with aplomb, rendering it suitable for either solid- state or tube amplifiers.

Technological advances are all well and good, but gear also has to be voiced. Here is where Bea Lam steps in. Though the family pedigree of the company can be traced from David to his son Luke Manley, it is also the case that Luke’s wife, Bea, plays a key role in helping to voice the gear. She also has solid chops when it comes to tube technology. Perhaps audio is not always as much of a man’s world as it may sometimes seem to be.

To put the TL-7.5 preamplifier through its sonic paces, I matched it with a variety of monoblock amplifiers, including the Classé Audio CTM-600, the Ypsilon Aelius, the Octave Jubilee, and the new Siegfried. I ran it only in a balanced configuration because I felt it would subvert the design to use it in single- ended. When I first listened to it with the Classé, I was struck by the sheer sweep and verve of the preamplifier. The Classé, which is also a balanced design, boasts just about the lowest noise floor of any amplifier I have heard. It seems to pluck musical cues out of the background that were previously buried or effaced. With the TL-7.5 this quality was even more in abundance, particularly in the midbass region, where the VTL was simply unrelenting in its grip and control.

But with both the Classé and the Ypsilon Aelius, which is meant to run single-ended, I was not fully satisfied with the sound. The Classé was somewhat thinner than I would have liked, which I ascribe to the VTL TL-7.5 showcasing the amp’s shortcomings. At $14,000, the Classé punches way above its weight, but it is not in same league as the VTL. A solid-state amplifier coupled with the VTL should preferably be a balanced design on the level of a Boulder amplifier or Dan D’Agostino’s new Momentum. I quickly realized that the Aelius simply must be run single-ended because it surrenders a good deal of its otherwise remarkable performance when run through its pseudo-balanced input. In my system, the TL-7.5 preamplifier was best able to display its qualities when coupled with the Siegfried. Hearing the preamplifier through it allowed me to discern its character more fully.

One characteristic that certainly came through loud and clear was its bass control. One of my favorite CDs for testing the organic nature of the bass line is Kenny Burrell’s Handcrafted [32 Jazz]. On this extremely well-recorded album, the bass line can sometimes become a bit floppy if the equipment isn’t up to the challenge of reproducing it. That certainly isn’t the case for the Wilson Alexandria X-2 Series 2 and the two Wilson Thor’s Hammer subwoofers that I use. And the VTL preamplifer rose handsomely to the challenge of feeding information to all those woofers. Instead of the bass becoming a muddy blur, it was easy to pick out the downbeat of each bass line, which endowed the individual cuts with a sense of propulsion. The sound of the bass itself was also in proportion with the drums and guitar, not bulgingly ostentatious but discrete and emphatic. It was the New Yorker jazz critic Whitney Balliet who once pointed out that the standup bass, even more than drums, can set the pace for a small ensemble. Lose it and you end up losing a fair chunk of the music. For sheer energy, it’s hard to exceed the Sheffield Lab LP of Harry James on the cut “Cherokee.” The drums were rendered with a whomp that left more than one visitor agape at their sonic power. Nothing overly ripe or plump here. Ditto for Monty Alexander on Stir It Up! The Music of Bob Marley [Telarc/ SACD]. On the cut “The Heathen,” for example, it sounds as though the drums are being clubbed, which, come to think of it, they probably are, at least judging by the ferocity which they were reproduced on system. Yes, once in awhile I permit the inner audio child to emerge and let the system cut loose.

A CD that I have become fond of for testing ambient information and timbral accuracy is MA Recordings’ The Lute Music of J.S. Bach, which features the supremely talented lutist Eduardo Eguez. Despite the myth that Wilsons are loudspeakers for head-bangers, the X-2s have never failed to fascinate me with their ability to reproduce small nuances and shadings, microdynamics, if you will. This CD—made by the engineer Todd Garfinkle, whose recordings consistently seem to be of the very highest quality—possesses an abundance of ambient information. The combination of the TL-7.5, Siegfried amplifier, and Transparent Opus MM2 speaker cable that Manley lent me brought this recording to its highest level of performance. Particularly striking were the amount of hall air that was reproduced and the plangent sound of the lute. It was almost as if the instrument’s strings had been audibly tightened to produce a more taut and focused sound. The plain fact is that low-level detail retrieval is notably better with the Series III preamplifier than with its predecessors.

This also allows the TL-7.5 preamp to preserve the dynamic scale of an orchestra more vividly and generously than many other preamps. The TL-7.5 has the ability seemingly to push more air into the soundstage and to capture delicate filigree in the treble. It provides a hugely expansive soundstage, which envelops the listener, whether with the Rolling Stones on “Sympathy for the Devil” or the Vienna Philharmonic playing Pictures At An Exhibition. Again and again, I was impressed by the power and punch, the dynamics and speed of the VTL preamplifier. But most impressive of all was its ability to play the loudest and most complex passages without even a hint of compression.

So does the TL-7.5 have any real downsides? It may not appeal to anyone looking for the warm rich sound that used to be associated with tubes. You won’t find yourself bathing in the sonics; instead, the preamp’s distinguishing characteristics are tremendous drive and openness. There is a regularity to the beat— aided considerably, of course, by the dCS Scarlatti, which, in my view, produces the steadiest rhythm of any CD player extant— that makes musical lines even more intelligible and distinct, no matter how many instruments may be playing simultaneously. Many manufacturers appear to be searching for a more neutral sound, one that effaces the colorations long associated with tubes. This does not have to result in sterility, but it does mark a break with the past—one that some audiophiles abhor. I’m not one of them. To me the aspiration has to be what we hear in a concert hall. Nothing can really replicate that marvelous clarity and sense of aliveness. But surely that doesn’t mean that using the real thing as reference is mistaken. Quite the contrary. The TL-7.5’s majestic soundstage and dynamism are staggering. If you already own a TL-7.5 preamp, upgrading it is a no-brainer. And if you’re contemplating taking the plunge for a new preamplifier, an audition might be all that it takes to entice you to leap.

SPECS & PRICING

Tube complement: Two 12AU7
Inputs: Four balanced/XLR or RCA
Outputs: Two balanced, two RCA, two RCA buffered tape out
Gain: Balanced mode 19.2 dB, singled-ended 13.2 dB
Output impedance: 25 ohms
Input impedance: 50k ohms
Dimensions: 17.5” x 4” x 17.5” (Control Chassis); 17.5" x 6" x 17.5" ( Audio Chassis)
Price: $20,000

VTL Amplifiers, Inc.
4774 Murietta Street, Suite 10
Chino, CA 91710
(909) 626-5944
vtl.com

ASSOCIATED EQUIPMENT

Continuum Caliburn turntable with two Cobra tonearms; Airtight Supreme and Lyra Titan mono cartridges; dCS Scarlatti CD/SACD system; Messenger and Ypsilon PST-100 Mk. ii preamplifiers; Classé CTM-600, Ypsilon Aelius, and Octave Jubilee monoblock amplifiers; Wilson Audio Alexandria X-2, Series 2 loudspeaker and Wilson Thor’s Hammer subwoofers; Basis Audio and Stage III cabling.