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SST Thoebe II Preamplifier and Son of Ampzilla II Power Amplifier

SST Thoebe II Preamplifier and Son of Ampzilla II Power Amplifier

Back in the day (and the day I’m talking about is close to forty years ago), the great designer James Bongiorno attracted a lot of attention with his crazily-named designs—not to mention his wacky hats, suits, press releases, and letters to audio journals. These designs also pricked up a lot of ears for just how good solid-state electronics could sound. I refer to his Ampzilla and Son of Ampzilla amplifiers, his Thaedra and Thoebe preamplifiers—surely only Bongiorno could link invocations of trashy Japanese disaster movies and ancient Greece—which he marketed via the company he founded, Great American Sound or GAS (I don’t even want to speculate what was on his mind when he came up with this, but surely the scatological implications can’t have been accidental). Bad health deprived him and high-end audio of a couple of decades of what would have been his prime as a designer. In the aughts he started up a new company, called Spread Spectrum Technologies, and 13 years before his death in 2013, he was able to introduce fully updated versions of Ampzilla, renamed Ampzilla 2000, and a new preamplifier he christened Ambrosia, named for the food of the gods in ancient Greece or, alternatively, a food that conferred immortality. True to himself to the end, the man was incapable of understatement. I was privileged to review—rave review, I should add—these two products in 2012 (Issue 219) and even more privileged to get to know James for a short while. Although we never met in person, we talked several times by phone. In my view those products are as good as anything you can buy—and fully worthy of becoming classics.

At that time, James had already begun new versions of the Son of Ampzilla and Thoebe preamplifier, both monikers retained only with “II” suffixes added. The name Thoebe brought back some wonderful memories, because it was my favorite of all the preamplifiers I owned prior to Dick Schoener’s Nova. And I liked the Thoebe much better when it came to functionality because it wasn’t minimalist. James believed control units should control and so included bass, treble, and balance controls, stereo/mono switching, and independent tape loops with cross-recording and full monitoring. The Thoebe II perpetuates this tradition, losing only the tape loops (does anybody actually tape anything any longer?).

But I’m getting ahead of myself. While the new products originated with Bongiorno, the cancer he’d battled for over two decades claimed him before the designs were in any sense functional. Bongiorno’s company was acquired by Wyred4Sound, where E. J. Sarmento, the resident designer there, completed them. I choose the word carefully: completed, not finished. According to SST’s Tony Holt, the products represent about seventy percent collaboration between Bongiorno and Sarmento and thirty percent Sarmento on this own. “Son of” is surely an apposite name for the new Ampzilla amplifier because it’s a chip off the old block, beginning with a massive 20-pound toroidal power supply. The circuit is fully balanced, configured to be extremely quiet, and provides A/B switching between balanced and single-ended modes; all jacks are gold-plated. Speaker outputs are via heavy-duty binding posts. The amp is servo-controlled with isolated and fully regulated front-end voltage supplies. There is a welcome turn-on surge delay, and thermal protection shuts the amp down if presented with any condition that might damage it (this never happened while I was using it). The power output is 220Wpc into eight ohms, 350Wpc into four. At no time during my use—mostly driving Quad 2805 electrostatics, but also Harbeth’s Super HL5 Plus, and the new Falcon LS3/5a—did the amp exhibit any behavior that suggested less than consummate ease, composure, and stability. The base price is $3500.

As regular readers of mine know, I believe fervently in bass and treble controls. Bongiorno told me he liked them because “no room is perfect.” I agree, but conventional tone controls are generally speaking much too broad in their effects to be of much help in correcting room modes. But when it comes to source material, broadband tonal correction really can make an excessively bright recording listenable—and let’s face it, most recordings are a little bright owing to the proximity of the microphones—or warm up one that is bass-shy (e.g., most of the George Szell recordings for Epic and Columbia are both bright and bass-shy). Initially I wondered if the centers weren’t too high in the bass—300Hz, the low-end of the midrange—and too low in the highs—3kHz, the low-end of the high range. But slopes are so cannily chosen I was completely won over. Used with care, these controls can transform any of number of tonally unmusical recordings into pleasing and listenable experiences.

The operation and display of the balance control were initially confusing to me. I’ll explain: When the balance control is selected, on one side of the display an arrow appears and on the other side, you see a numerical indication of level. The arrow points in the direction of the channel being raised and is illuminated on that side of the display. Thus, if you’re raising the volume in the left channel, the arrow will appear on the left side of the display pointing toward the left speaker, while the numerical setting appears on the right. This makes perfect sense except that the symbol does not look particularly arrow-like, so the first time I used the balance control, I assumed that the numeric display was on the same side as the affected channel. When the volume was raised in the opposite channel I rechecked all my connections; as they were correct, I was thoroughly perplexed until I realized that that symbol was supposed to be an arrow. This sort of misunderstanding could easily have been prevented if the manual had provided some explanation; as written, it’s rather barebones for a unit of this sophistication.

On the plus side, every one of these features is accessible via the handset, which makes it my kind of remote. However, it’s not stock, but rather an optional accessory costing $175. This seems to me rather steep, but I acknowledge that it’s a very sophisticated device and impressively constructed from what feels like a solid block of aluminum.

A Class A headphone amplifier comes standard in the Thoebe, with a pair of ’phone jacks accessible via the front panel. I don’t much listen to headphones, but if you do, this should fill the bill about as well as anything you’re likely to find out there. And one feature I really appreciated is that only one of the jacks automatically mutes the main outputs—a smart feature, as you don’t necessarily always want the speakers muted when listening to headphones. Connectivity consists in three pairs of single-ended (RCA) and one pair of balanced (XLR) outputs, and four pairs of line-level RCA and one pair of XLR inputs.

The Thoebe II can also be purchased with a built-in phonostage and/or an internal DAC at an additional $500 each. The phonostage takes up one of the RCA inputs, while the DAC option adds USB, coaxial, and TosLink inputs. If purchased together, SST knocks $250 off the $1000 total. So a fully tricked-out Thoebe II with phonostage, DAC, and remote will set you back $4250. This seems to me to be very good value: like the amplifier, it worked absolutely flawlessly, was a joy to use, and in ergonomic terms struck me as about as close to perfection as you can get. If I did not already own a preamplifier that serves my needs perfectly well, the Thoebe II would be a very tempting purchase to consider (though if Sarmento is ever tempted to make a change, I would wish for a stereo/mono switch).

When it comes to the sound, these units remind me of the Ambrosia and Ampzilla 2000: the same quietness, smoothness, transparency, dynamic range, and that elusive impression of body, dimensionality, and solidity. It’s been three years since I had their more expensive brethren in the house, but I suspect that in an exacting A/B comparison, considerable concentration would be required to distinguish one pair from the other. Given their lineage and the fact that they are fully contemporary solid-state designs of great competence and sophistication, describing the sound does not invite purple prose or any other sort of colorful language, which is to say that it is neutral, transparent to the source, and in any practical sense distortion and noise-free.

 

Because the review period was limited, I auditioned Thoebe and Son as a combination. As found with all exceptional equipment, there is on the best recordings a gratifying impression of lifelikeness and vitality, simultaneously relaxing yet wholly involving. There is nothing about the basic circuitry of these units that calls untoward attention to itself. If forced to the wall, as an initial impression I might say that I wondered if there weren’t a very slight tilt toward the yin side of the spectrum, but I suspect this owes to the fact that I had just come off reviewing the Benchmark AHB2 amplifier, which is anything but. I am especially impressed, but not surprised, given the lineage, that the bass here is so powerful, deep, superbly defined, and absolutely unflappable. At the same time, there is none of that excessively tight, punchy bass beloved of some audiophiles but which has no real equivalent in live music, where bass in addition to being strong is also warm, rich, and full.

Moving to the midrange—vocals in particular—as it happened, the end of the review period coincided with an appearance by the Anonymous Four on their farewell tour. They sang a program of seasonal music in a Greek Orthodox church in Orange County that boasts splendid acoustics. The next day I played several of their albums that contained pieces I’d heard in their live concert program. Now, clearly, it would be absurd to state that the sound resembled what I’d heard at the concert since the recordings span over a quarter century and involve different venues and one change in personnel. However, in the strictly timbral sense, the voices in the group (as currently constituted) were truthfully reproduced, and that is as tough a tonal acid test as I know, at least with musical sources.

These electronics do not favor any type of music over another, but it being the holidays, I did play a lot of choral music from large and small ensembles, several of them recorded in churches or church-like venues, again large and small. These typically have rather “wet,” that is, reverberant acoustics, and the best recordings—right now I’m listening to the Huddersfield Chorus singing Christmas music—capture plenty of ambience and hall sound. Thoebe and Son rendered these thrillingly, and quite spectacularly when large organ and brass were added, as in a program recorded in St. Paul’s. Another such recording, not seasonal, but tremendously thrilling is Paul McCreesh’s A Venetian Coronation 1595, which reconstructs the coronation ritual of a Doge in sixteenth-century Venice. The performing forces consist of a small choir with soloists, an organ, and a collection of period instruments, including natural trumpets and drums. At one point near the beginning, the drums and trumpets begin in the far distance and come forward, building in volume and intensity until they reach the front, where they perform a sensational toccata that is spread across the entire soundstage. These are compositions in which the deployment of the performers in the physical space is an essential part of the music’s meaning and experience. It is also music rich in colorful instrumental timbres and complex contrapuntal textures. Thoebe and Son reproduced it an ideally mediated combination of organic blend and textural clarity. When you find the right playback level, the sense of being in a vast space with gloriously resonant acoustics is uncannily real—Peter Walker’s “window” into the concert hall.

One characteristic of the phonostage that struck me right away was the sensational dynamic range, which is also a quality of the Ambrosia’s phonostage. The presentation was equally free from glare or tonal anomalies and was superlatively quiet. At $500 it seems to me to punch far, far above what its price-point might suggest, fully competitive with units costing a couple of grand. With just 42dB of gain, the phonostage is suitable for high-output pickups only. As I currently have none of these on hand, my listening impressions were based on the Ortofon Windfeld through my Quicksilver transformer. I’ve been using the Quicksilver on and off for nearly thirty years now, so I think I can compensate for its contribution to the sound, which is exceedingly small apart from amplifying the signal: a very neutral device, mirroring Thoebe’s phonostage, and the Windfeld has also been widely recognized for its neutrality. To anyone contemplating a Thoebe who is also deeply into vinyl, I recommend the optional phonostage without serious qualification as both an outstanding bargain and a fine performer without regard to price.

The DAC is built around the ESS Sabre (9018) 32-bit chip, and features (according to the specs) an “asynchronous, galvanically isolated USB input” that supports up to 32-bit 384kHz PCM and DSD64 + DSD128.” I do not own a music server and am not yet into downloads, hi-res or otherwise, so I can’t evaluate it in this regard. Reviews I’ve read from writers who are rate it very, very highly for these applications. I auditioned the DAC only via the transport section of my Marantz SA8004 CD player. It performed very well, to my ears its presentation ever so slightly brighter than the 8004 on its own, but Marantzes are famously smooth, natural, and musical sounding. On balance, I fractionally preferred the Marantz by itself, but that was strictly a matter of taste, not a judgment as such against Thoebe’s DAC.

 But if you buy a Thoebe, should you go for the DAC option? Well, if you already have a high-quality CD player that you enjoy, I seriously doubt the Thoebe’s DAC will be an improvement, though it will be different (among other things, it doesn’t reclock the signal, which would be unreasonable to expect as its price-point). Taking, for example, the Anonymous Four recordings I referred to earlier, my preferences fall in this order: the Marantz used as transport feeding my Benchmark DAC1, the Marantz standing alone, and the Marantz feeding Thoebe’s DAC. The Marantz/Benchmark struck my ears as the most neutral, transparent, detailed yet natural reproduction; the Marantz alone was notably smooth, natural, and musical, with a bit of warmth yet without sacrificing detail; the Marantz/Thoebe DAC was a tad on the bright side, not at all warm, yet very listenable. In fact, all yielded excellent results that I could easily live with. But truth in reporting mandates I point out that several of these Anonymous Four recordings are also SACD, which was superior to all of the Red Book presentations. So if you’re buying the Thoebe (with DAC option) solely to replace the DAC section of your current DVD player, you may get better sound or you may not. But if you’re thinking of getting your feet wet by experimenting with a music server and downloads, it’s hard to see how you can go wrong, especially in view of the $500 ticket price, which as mentioned becomes a mere $250 if you buy it in tandem with the phonostage—so you can hardly lose.

As for the place of Thoebe and Son in the current market, the one area where advances in technology and design have unquestionably benefited the consumer is electronics in the broad middle category from below a thousand up to a few thousand per unit, right where these new offerings land. Are they better than comparably priced and spec’d products from NAD, Marantz, Rotel, Paradigm, McIntosh, et al? The short answer is probably not, because the overall excellence in this sector of the market is outstandingly high. That said, however, there will be subtle differences between them, especially depending on the associated components, which means that letting your ears decide is, as always, the wisest course. This combination does have one cachet, though: the bragging rights of their lineage and, what’s more important, reproduction of extremely high accuracy, resolution, and musical authority allied to build-quality that guarantees long and trouble-free performance for decades to come.

SPECS & PRICING

Thoebe II stereo preamplifier
Inputs:  Balanced on XLR jacks, unbalanced on RCA jacks (USB input for software updates)
Outputs: Balanced and unbalanced
Headphone amplifier: 338mW into 330 ohms
Gain: 11dB or 17dB (switchable)
Optional phono input: 42dB of gain
Optional DAC: Up to 384kHz/32-bit and DSD64 and DSD128 on USB, TosLink, coaxial
Dimensions: 17″ x 4″ x 14″ 
Weight: 25-28 lbs., depending on options
Price: $4250 as reviewed

Son of Ampzilla II stereo power amplifier
Power output: 220Wpc into 8 ohms; 350Wpc into 4 ohms
Inputs: Balanced and unbalanced
Outputs: Balanced and unbalanced
Dimensions: 17″ x 5″ x 9″
Weight: 40 lbs.
Price: $3500             

SPREAD SPECTRUM TECHNOLOGIES
4235 Traffic Way
Atascadero, CA 93422
(805) 466-9973
sst.audio

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