VTL Siegfried Series II Reference monoblock power amplifier Page 2

The big Siegfried IIs could play "small" and fast, in that they sounded similar to VTL's MB-450 Series III Signature, but with more power, grip, and slam. And slam was the word—the Siegfrieds had slam not in spades, but in dump trucks full! Of course, you have to listen to a recording with wide dynamic range to catch the micro end of the act.

Zubin Mehta and the Los Angeles Philharmonic's recording of Mahler's Symphony 3, while not the most revered performance of the work, is still a great one—especially for its sound in an upcoming vinyl reissue, even if the brass can sound a bit bright in the somewhat distant perspective (2 LPs, Decca/Analogue Productions). Through the Siegfrieds, the brass was appropriately bright but not at all strident; the strings, particularly the larger ones, were rich; the recording venue was big; and the dynamics were stupendous. Listening to the speed and depth of the timpani strokes that open side 2, if I hadn't known the Siegfrieds were in the system, I'm not sure I'd have been able to tell I was listening to a tube amp, so taut, deep, and well-structured were the impacts of mallets on drumheads.

After spending a few months with the Siegfrieds II, with occasional returns to the darTZeel NHB-458s, it became clear that the gap between today's better high-powered tubed and solid-state amplifiers has considerably narrowed—at least between these two examples. Both were sweet and extended on top, taut and well extended on bottom. The Siegfried's lowest octaves were in no way soft or lacking in either full extension or dynamic punch, nor were the darTZeel's lowest octaves overdamped or mechanical, as detractors of solid-state charge.

The tubed Siegfried II's midband was rich and attractively creamy, without sounding too warm or billowy. The solid-state darTZeel's midband was somewhat less so, but was not at all thin or bleached—and whatever minor amounts of textural richness were lost were more than made up for by an increase in transparency and my ability to "see" somewhat farther into the soundstage.


There's no doubt that having a dozen output tubes per channel does, ever so slightly, limit ultimate transparency—but to the Siegfried II's credit, this wasn't something I noticed until I switched back to the darTZeel, which is the state of the solid-state art. And when I did, I immediately missed aspects of the VTL's sound.

As when I played a new reissue of Beethoven's Violin Concerto, with soloist Leonid Kogan and the Paris Conservatoire Orchestra led by Constantin Silvestri (LP, EMI/Electric Recording Company SAX 2386). This release was pressed in a limited edition of 300 and costs ú300 ($500). If you think the prices of used LPs are dropping, or that ERC is charging too much for this all-tube reissue (restored tube lathe, tube electronics, etc.), consider that an original pressing of this rare 1959 release in VG+ to VG++ condition sold on eBay last December for $2629!

I packed along a test pressing of the Beethoven to the 2014 Consumer Electronics Show in January, where I played it in the VTL room, for Luke and Bea Manley and Wilson Audio's Peter McGrath, through a pair of Wilson Alexia speakers. McGrath, who has long been away from vinyl, responded by groaning, "Oh, no." Mesmerized by this recording's magnificent string tone and textural beauty, he admitted that neither could possibly be conveyed by digits.

Back home, as good as the darTZeel's tonal and textural rendering of this recording was, the Siegfried II's, though slightly less transparent, was silkier, sweeter, and more true to the sound of a violin. This was in tetrode mode, with the Damping Factor set to Medium, the setting at which I thought the Siegfrieds sounded best, and the one I used for all of my auditioning.

Detours: Triode Mode and Damping Factor
VTL describes the Siegfried II's tetrode/triode switching as "on the fly," but the changeover takes a few minutes (counted down on the amps' front-panel displays), which prevents instantaneous comparisons. Still, I compared a good, recent reissue of Chet Atkins and Les Paul's always-enjoyable Chester & Lester (RCA APL1-1167/Exhibit eXLP-44061).

It seemed a good choice: Atkins and Paul were plugged into tubey-sounding amps to begin with. I understand the enticement of triode mode: The sounds of the two guitars floated, gossamer-like, on a billowy soundstage, producing a sensation of aural melting. Taken as an overall sonic experience, it couldn't be beat—but switching to tetrode mode for "It Had to Be You" revealed a cleanly rendered rhythm guitar that had gotten lost in the triode ooze behind the drummer's brushwork. Instrumental transients snapped into place, particularly the electric bass.

On the other hand, though either mode was more than mesmerizing when reproducing the Electric Recording Company's reissue of Johanna Martzy's recording of J.S. Bach's Sonatas and Partitas for Unaccompanied Violin (3 LPs, EMI/ERC), triode was definitely the way to go. The same went for a sampling of János Starker's performance of Bach's Suites for Unaccompanied Cello (Mercury Living Presence SR3-9016/Speakers Corner or Golden Imports). For solo string performances, small acoustic ensembles, or singers, particularly women, the big Siegfried IIs in triode mode attained much of the delicacy, purity, and speed I normally associate with low-powered, single-ended-triode tube amplifiers. If I owned the Siegfrieds, I'd mostly leave them in tetrode mode, and reserve triode mode for special occasions such as those listed above. But this is a matter of musical taste; no doubt some would leave them parked in triode all the time.

As for the damping possibilities, too much closed down the overall sound; too little bloated it, mostly in the bass. I chose the Medium position, though again, which I preferred depended on the music.

Using the high-resolution digital edition of Doug MacLeod's wonderful There's a Time (DVD-R, 176kHz/24-bit, Reference HR-130 HRx), Low Damping Factor produced a deeper stage and a pleasing softness in the bass. Repeating the track with Medium DF brought MacLeod's voice forward, but increased the focus and tightened bass transients. High DF flattened the image, dried up the ambience, and seemed to limit dynamics. If you wanted to, you could optimize the DF setting and output mode for every recording in your collection.


The Siegfried II's renderings of women's voices were equally impressive. It proved ideal for Lost in Romance, Lyn Stanley's self-published debut LP of cabaret jazz (which received an "11" from me for sound on Analogplanet.com). Stanley's decided to put little or nothing electronic between the microphone and the listener, which these days is pretty daring; the result is an astonishing vocal recording, mixed by the great Al Schmitt at Capitol Studios, that the Siegfrieds believably reproduced, producing an impressively three-dimensional voice between the speakers.

I spent an afternoon comparing a new mono reissue of John Coltrane's Blue Train (LP, Blue Note/Music Matters MMBLP1577) with an original Blue Note pressing, a Japanese Toshiba reissue, and Classic Records' reissue. The Siegfrieds, with their extended HF response and low coloration, passed along all of the subtle and not-so-subtle sonic differences among these versions without homogenization.

Remarkably quiet, wideband, as linear and tonally neutral as the best solid-state amps, and with just a kiss of the effortlessness tube lovers find so addicting, the VTL Siegfried II was as neutral and as uncolored as any tube amp I've listened to.

If you want warm, soft, and rolled off, there are tube amps that will deliver that. Not the Siegfried II. No one—not even the warm, soft crowd—wants plummy bass, and the Siegfried didn't produce it. In fact, the Siegfried's bottom-end performance was so good that I never felt the need to switch back to the darTZeel NHB-458s for one of my many evenings of listening to rock. In addition, it gave nothing away in terms of overall speed and transient clarity to achieve its impressive power output.

If I had to describe the Siegfried II's overall sound in one word, I'd choose creamy. But that creaminess wasn't overly rich. While the Siegfried II's sound was similar to that of the smaller MB-450 Series III Signature, the Siegfried was more coherent and delivered greater upper-octave sonic sophistication. If John Atkinson's measurements of the Siegfried II reveal more distortion than the better solid-state amps produce, it didn't translate into anything audible in my listening room.

If you've heard the original Siegfrieds and have drawn conclusions different from mine, I'm with you. I and a group of journalists from around the world heard the originals in Dave Wilson's living room, following a CES a few years back. We were there to compare the Alexandria Series II with its predecessor, and we auditioned both editions of the speaker using the Siegfrieds and Dan D'Agostino Momentum monoblocks. I thought the Momentums, which I reviewed in February 2013, stomped all over the original VTLs, which sounded veiled and lackluster overall.

The Siegfried Series II Reference is another story altogether—a huge improvement over the original in every performance parameter. The amp had no trouble driving the efficient Wilson Alexandria XLFs, whether in my small room or my friend's big room. And if you have relatively inefficient speakers in a large room, I expect these 600+W powerhouses will have no trouble there either.

Although Luke Manley left with me a few extra 6550 tubes, "just in case," the Siegfrieds proved 100% trouble free in the months they were in service here. You should expect that for $65,000/pair, along with great sound. In the VTL Siegfried Series II References, I'm confident that that's exactly what you'll get.

VTL Amplifiers Inc.
4774 Murrieta Street, Suite 10
Chino, CA 91710
(909) 627-5944