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VTL Siegfried Reference Series II Monoblock

VTL Siegfried Reference Series II Monoblock

A few years ago a good friend took me to visit the office of Jon Platt, a top executive in the music industry who represents artists like Beyoncé and Jay-Z. It soon became clear that Big Jon, as he is known, is also a very serious audiophile, with a full rig in his home. In his office I got to hear the Wilson Alexandria X-2, Series 2 loudspeaker together with the VTL Siegfried amplifiers. It made a big impression upon me. Layer after layer, row after row of an orchestra or big band was revealed with rich, sumptuous clarity. I was truly impressed not only by the Wilsons, but also by the ease that the Siegfrieds displayed in controlling them. There was something magical about the synergy between the two. Big and powerful amplifiers can have a huge impact on the performance of even relatively efficient loudspeakers like the flagship Wilsons, and the Siegfrieds clearly did.

So it was with more than a pinch of interest that I followed VTL’s introduction of a new version of the Siegfried. When I first heard the Siegfried at the Rocky Mountain Audio Fest, it quickly became clear that VTL had upped its sonic game. I was eager to audition the amps in my own system. After TAS editor Robert Harley signed off on it and after I lugged the Siegfrieds down a flight of stairs with the aid of a chum, I was off to the races. And how! At about 800 watts of tube power in tetrode mode (at the push of a button it can also run in triode), the Siegfried is one of the more powerful amplifiers on the planet. It shows in ways both large and small. The Siegfried does nothing by half-measures. Quite the contrary. It is an amplifier with tremendous brio and swagger. Its scale is vast, its dynamics explosive, and its power reserves seemingly endless. Notes explode out of drums as though a shotgun had been fired. You will approach it with respect—its sheer size and weight bespeak seriousness of intent—and likely end up embracing it with fervor.

In Wagnerian mythology the boisterous Siegfried has to learn the meaning of fear, which he does when he alights upon a slumbering Brünnhilde. So this amplifier is aptly named; it may scare the dickens out of audiophiles who aren’t accustomed to listening to a grand piano sound almost as majestic as it does in real life or to the full three-dimensional, gut-wrenching bass of a rock ’n’ roll recording. Turn the volume up and the Siegfried will only get louder without any hint of compression. Your room will appear to be swelling with sound that wants to burst the confines of the walls. If I had to choose one word to describe the VTL Siegfried, then it would be grandeur.

The sheer oomph of the Siegfried really should come as no surprise because VTL has always specialized in what might be called the big bang theory of high-end audio. It wants that French horn in the back of the orchestra to come roaring out in all its lusty glory over the strings. The company was founded several decades ago by David Manley, then purchased from him by his son Luke. Now, together with his wife Bea Lam, Luke has taken VTL into a new era, one that leaves behind both the sonic and mechanical problems that often plagued tubed amplifiers, particularly ones that aspired to high power. The blunt fact is that high power and tubes have not always mated well together. When you pack twelve or twenty-four KT-88 or 6550 output tubes into an amplifier, then it isn’t a question of whether but when a tube will arc. Sad to say, but the quality of tubes nowadays is simply not what it was in days of yore, which is why the originals go for such a premium on the Web. The results—scorched boards, blown resistors and traces, and so on—could be most unpleasant for owners, who, more often than not, needed to be handy with a soldering iron.

With VTL’s deployment of microprocessors both for starting up and monitoring amps during use, those days are long over. Unless you are a glutton for punishment, you can only welcome VTL’s introduction of a measure of comfort into the listening experience. No longer will you have to sit listening with a wary eye on a bank of tubes that could explode at just about any moment. Instead, most of VTL’s amplifiers incorporate a fault-sensing system that can detect if a tube is about to blow and shut it down before it can do any damage. (A small LED will blink next to the tube to indicate the troublemaker that needs to be replaced.) The Siegfried contains a host of other features that make it a user-friendly piece of equipment, including a front display panel that counts the numbers of hours that the tubes have been playing—about 2000 hours is a good time to change them.

At the heart of the Siegfried—and what truly sets it off from its competitors—is its precision regulated power supply. The power supply ensures that the tubes keep their correct bias— no more fiddling to set it by the owner. It’s done for you. At the same time, Siegfried regulates the power supply to avoid the voltage sag that typically accompanies dynamically demanding passages as the amplifier draws upon the power supply.

Since a number of these features were also present in the Series I version of the Siegfried, which I reviewed for TAS several years ago, what’s the big deal about the new one? Why the fresh designation?

For one thing, it boasts a fully balanced audio circuit that uses 12BH7 driver tubes instead of the 6350s in the previous version, no global negative feedback, new output transformers, Mundorf silver/oil capacitors, and four settings—low, medium, high, and max—to allow users to adjust the output impedance of the amplifier, depending on how much damping you feel needs to be applied to the woofer in your speaker. I used the medium setting. The balanced circuit clearly seems to have lowered the noise floor. I found that the fully balanced VTL 7.5 Series III preamplifier drove it in exemplary fashion, and Transparent Audio was kind enough to send me both a balanced interconnect and an extra set of Opus MM2 loudspeaker cables (here I should also note that Transparent sent two hefty 20-amp power cords that substantially boosted the performance of the Siegfrieds). I have found the Opus cables transmit a sense of dimensionality I have not yet heard another cable supply. In this case, they seemed to mate beautifully with the Siegfried and Wilson XLF. It is not essential to run the Siegfried with a balanced preamp—it will convert the signal at the input—and I found that the non-balanced Ypsilon PST-100 Mk. II upped dynamics another notch.


What do all the changes to the Siegfried amount to sonically? The first and most audible change from the earlier Siegfried is that the new one not only sounds quieter with blacker backgrounds, but also much more sophisticated, particularly in the treble region. There was a lot of nitpicking in some audiophile precincts about Version One’s performance, and allegations that the various monitoring systems and voltage regulators that VTL employed were intruding upon the signal path. Moving to a fully balanced circuit has more than adequately addressed any lingering sonic issues.

In the new version the treble consistently sounds supple and smooth. One way in which this manifests itself is that singers sound more open and powerful. Take Mavis Staples. On her new album One True Vine [ANTI-], the huskiness of her voice comes through with terrific force on the first cut “Holy Ghost.” It’s amazing to hear it sound like this, not just because Staples is in her seventh decade and doesn’t appear to have lost a bit of her power, but also because the Siegfried allows you to hear that she’s flooring it without any apparent strain or effort. On a lesser amplifier her voice would be thinned out and a little more strident. Not with the Siegfried. “Here I stand, I can do no other,” Staples seems to say.

This ability of the Siegfried to flesh out the voice of singers was also palpably apparent on Leonard Cohen’s album Old Ideas [Columbia]. Cohen is one of those fellows who seems to draw admirers and detractors in equal measure; in this case, count me, like fellow TAS editor Neil Gader, who generously bestowed this album upon me, as belonging to the former camp. On cuts like “Show Me The Place,” the gruff, almost rebarbative sound of Cohen’s voice comes through with plangent, unforgettable intensity. You almost feel like you could count every hoarse reverberation in a single syllable. Nor is this all. I would be totally remiss if I failed to note that the sheer size of the soundstage, which was gigantic.

If the Siegfried has a hallmark, it is that it excels at delivering a vast image with tremendous control over the individual instruments, each textured and layered in the hall. This is all to the good when it comes to just about any genre of music. I’ve simply never heard a grand piano delivered with this kind of shuddering depth. Of course the Wilson XLF reaches into the nether regions. But the Siegfried, with its gobs of current, propels it into those regions and never lets go. With the Siegfried you hear that extra layer of richness down there and not just on bass-heavy recordings. Consider—and if you haven’t, you should—Andras Schiff’s or Murray Perahia’s superlative recordings of the Bach partitas on the ECM and EMI labels, respectively. On each, the Siegfried allows you to follow the left hand of the pianists with exemplary precision; the subterranean bass notes that are often softly sounded establish a mysterious sense of ambience that only the best stereo can offer. But above all, the Siegfried seemed to capture the richness and texture of a grand piano, a facet that came particularly home to me after listening to Jeremy Denk perform the Goldberg Variations at the Kennedy Center in Washington, DC. The Siegfried just wasn’t that far off from the real thing in sonority and scale.

Am I describing an amplifier that can provide the big picture, that’s the sonic equivalent of sledgehammer but lacks finesse? Not a chance. There is no gainsaying that the Siegfried is a big tube amplifier that cannot completely obliterate the line between it and solid-state. If you’re looking for the ultimate in precision and delineation, the tautest possible control in the bass, then you should look elsewhere. The Siegfried almost by definition is going to have a higher noise floor than its solid-state competitors. But this sentence can be easily turned on its head. The top-drawer solid-state amplifiers will not match the Siegfried in midrange magic and suppleness—the effortless sense of continuous expansion that only tubes seem to be able to provide, not simply in the mids but also in the bass region. What the Siegfried does is come the closest of any high-powered tube amplifier that I’ve heard to effacing the line between it and solid-state, while sizably improving upon the tube amplifier’s strengths. Its control over tiny vocal quavers, pitch changes, or delicate vibrato is excellent. This is a great marriage of modern and old technology.

In sum, VTL has produced an amplifier that comes about as close to doing it all as anything on the market. Its performance, particularly on large-scale works, is magnificently engrossing. When I placed Stillpoints footers underneath the loudspeakers and other equipment, the strengths of the Siegfried became even clearer. Put plainly, I wallowed in the sound, agog at the sheer scale, the passionate music-making it conveyed. Is it neutral? Maybe in terms of its measurements. But neutral is not a term that comes to mind when thinking about the Siegfried. This amplifier offers an experience. It is about as far removed from a cool and restrained solid-state sound as is possible to imagine. It revels in offering a burnished and vibrant sound that came through whether it was driving the Wilson XLF or the Magnepan 3.7i. This is, moreover, a sound that, like analog, is at the heart of the hobby. You can glory in this amplifier. Over the years, I’ve heard many of VTL’s amplifiers, including the MB-750 monoblocks, the Wotan, and the original Siegfried. This is by far VTL’s most potent offering. It isn’t simply a pleasure to listen to but a delight.


Vacuum tube complement: Twelve 6550 or KT-88, one 12AT7, two 12BH7
Output power: Tetrode, 650W; triode, 330W into 5 ohms, 20Hz–20kHz <2.5% THD
Input sensitivity: Variable between 1–2V, depending upon DF setting
Input impedance: 45k ohms
Load setting: 5 ohms
Optimum load range: 4 ohms–8 ohms
S/N ratio: 110dB, 120Hz
Dimensions: 11.5″ x 24″ x 24″
Weight: 200 lbs. each (net)
Price: $65,000 a pair

Associated Equipment
Continuum Caliburn Turntable with two Cobra tonearms, Lyra Atlas and Miyajima mono Zero cartridges, dCS  Vivaldi CD/SACD playback system, Wilson Audio XLF and Magnepan 3.7i loudspeakers and Wilson Hammer of Thor subwoofers, Ypsilon PST -100, Mk. II preamplifier, VPS 100 phonostage, and SET Ultimate monoblock and Boulder 2150 monoblock amplifiers, Transparent Audio MM2 Opus cabling and power cables, Stillpoints Ultra 5 and Ultra SS footers


By Jacob Heilbrunn

The trumpet has influenced my approach to high-end audio. Like not a few audiophiles, I want it all—coherence, definition, transparency, dynamics, and fine detail.

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