Published On: January 11, 2009

Theta Dreadnaught Amp reviewed

Published On: January 11, 2009

Theta Dreadnaught Amp reviewed

Theta is better known for digital but their Dreadnaught power amp has some serious weight and respect from those who know. Theta, now owned buy Morris Kessler of ATI, packs a lot of heat in the their audiophile amps but this was their first shot over the bow and it was one people took notice of.

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Why, this far into the A/V era, are we still surprised when a component earns praise for its 'crossover' ability? You know: the ones which sound as good in a purist, 2-channel music-only set-up as they do in a 5.1 installation, or vice versa. Am I alone in thinking than an-amp-is-an-amp-is-an-amp or a speaker-is-a-speaker-is-a-speaker? The alleged, indeed, mysteries of cinematic- versus music-only requirements create a whole school of red herrings because, after all, we're still talking about the reproduction of sounds, be they the human voice, massed instruments or a nuclear explosion. And yet a wide chasm still exists, despite the current music-only and full-blown home cinema differing ONLY in the number of channels.

Additional Resources
• Read audiophile power amp reviews from the likes of Krell, Mark Levinson, Audio Research, Linn, Naim, VAC, VTL, NuForce, Pass Labs and many others here.
• Read about tubes on the Audiophile blog, AudiophileReview.com.
• Want to read audiophile stereo preamp reviews? We have dozens from brands like ARC, Krell, Classé and many more.
• In the market for audiophile loudspeakers? Here are over 100 reviews from brands like Wilson Audio, THIEL, MartinLogan, Bowers & Wilkins, PSB, Vandersten, Magnepan and many more.

With discrete channels, digital encoding, unbelievably sophisticated surround processing and a number of other developments - most notably DVD - we should no longer even entertain such early-1990s and, at the time, necessary notions as the need for two systems if you want to optimise playback for both music and movies. If I had my way, the only time reviewers would wear different hats would be when assessing either music-only (e.g. 2-channel CD players, turntables or stereo pre-amps) or A-V-only (DVD video, monitors, line doublers) components. I have before me an amplifier so luscious that it's almost a shame it will only ever be sold as part of a home theatre system, with two-channel usage as an afterthought. And this is despite modularity which makes it purchasable as either a 2-, 3-, 4- or 5- channel amp, and operational details which beg for it to be used in stereo form. Hell, Theta would probably let you buy it as a monoblock if you were that profligate and/or purist.

However, the aptly-named Dreadnaught (Neil Sinclair revealing a prodigious memory by christening it in honour of a long-forgotten US behemoth amp of yore...) occupies a floor-consuming 448x214x597 (WHD) and weighs just over 45kg. Whatever one's commitment to total channel isolation, one would be grateful that this bulk houses all five channels. And, as it costs £3850 in stereo, plus another £850 per channel leading up to £6400 in 5-channel form, you'd be piddling away £8,600 extra for a quintet of mono units. But, oh! would five of them look devastating! For my money, the Dreadnaught is one of the most beautiful amplifiers I've ever seen, finished with such delicacy and styled with such subtlety that you forget it's actually a 5x200W monster. Even the top panel has been subjected to a designer's eye-and-hand, the unit's ventilation slots shaped to create an aesthetically-pleasing pattern...a far cry from off-the-peg mesh or mere perforations.

Dreadnaught's imposing front panel boasts swoopy, curved sections with a satiny finish, suggestive of the angels' wings motif which forms the Theta logo. Between them is a vertical section containing three LEDs and two buttons, the lights indicating 'standby' mode (main on/off is at the back), 'thermal' should any channel rise above the maximum operating temperature and 'surround' mode, showing that the surround bus is in use. The larger of the two buttons switches the amp out of standby, activating the stereo bus channels, while the smaller button activates from standby any channels assigned to the surround bus.

Depending on how many channels have been installed, the back will contain a vertical strip for each module. At the top of each is a newly-designed speaker terminal with a single screw fixing which grips both the + and - leads at the same time, under a crossbar which applies the pressure. Below are three LEDs, the first mirroring the thermal LED on the front, but in this case indicating precisely which channel; obviously, the single LED on the fascia only tells you that a channel is running hot, but not which one. Next to it are two LEDs to indicate if either the + or - internal fuse on the rail for that channel is blown.

Underneath the LEDs are the inputs, the top being a single-ended phono socket, the bottom an XLR input, followed by two toggle switches. The first chooses between single-ended and balanced, the second assigning the module to either the stereo or surround bus. And the extreme right of the panel, as viewed from the back, are two RS232 connectors (DB9 and RJ45) for connecting the Dreadnaught to an external controller including PCs and universal remote systems such as those from Crestron or AMX, remote trigger sockets which are activated by Theta's own processors and others, the main on/off rocker, the AC fuse holder and the IEC three-pin mains input socket.

Little information is forthcoming about the circuitry, so I'm assuming Class AB operation as the Dreadnaught never gets hot enough to suggest otherwise. Theta does, however, make much of the amplifier employing zero global negative feedback. Theta believes that small amounts of local feedback within a single gain stage do ensure circuit stability, while any signal delay will be minuscule. Global application of negative feedback, on the other hand, is too coarse, and the resultant artefacts will include 'serious' phase shift and intermodulation distortion.

Another key element of the Dreadnaught is its balanced operation. While some would like to think that the jury is still out on balanced-vs-singled-ended, the sceptics suggesting that its efficacy and benefits are only apparent when using long cable runs (the 6db extra gain notwithstanding...), I have no doubt that it in every way: quieter, more precise, more detailed, more dynamic.

Although I have to admit that Lexicon's MC-1, my processor of choice and that which I used for the surround sound evaluation, did not enable me to exploit balanced operation in surround mode, as luck would have it, I had the new Sugden Masterclass pre-amp and a GRAAF GM13.5 to hand to access the balanced operation in stereo mode. I know, this contradicts my plea from the opening paragraph, but I did hump the Dreadnaught from room to room to try it as both a purist stereo amp and as an A/V powerhouse. Also used were the Pioneer DV-414 DVD player, SME 10 turntable with SME Series V arm and Lyra Lydian m-c, Musical Fidelity X-LP phono stage, Marantz CD-12 CD transport and dCS's Purcell and Delius processors. Speakers included Wilson WATT Puppy 6 and Martin-Logan Scenario, Script and Cinema. Wiring consisted of various elements of Kimber and Transparent.

Given that this the A/V section of the magazine, it's obvious that priority must be given to its primary role - however arbitrary it now seems. Timing being everything, I can only thank the audio gods that both the DTS and Dolby Digital versions of DVD (Region One) arrived in time for the sessions. It was immediately apparent that this is a reference-grade disc, with not just visual but sonic evidence of Spielberg's utter genius. (Better still, it proved conclusively to me and others that DTS slaughters Dolby Digital, whatever the nay-sayers argue, but that's not a topic for discussion here.) The opening salvos, the sound and image switching from under water to above water, the myriad explosions, the conversations amidst gun-play, the roaring waves and other spectacular sonic events are enough to tax any system. Oh, and to convince me that sub-woofers do have their place. The engineers ensured that a clear directional path accompanied the gunfire, and thus the whole raison d'etre of surround sound is justifiable in a film of this calibre.

Read more on Page 2

Via the Dreadnaught, no transient was too quick, no explosion too deep, no thunderous crashing of waves too much for the amp's capabilities. Those who wear two hats could therefore point out just how apt the Dreadnaught is for an A/V role. Where it showed competence above and beyond the call of duty came in the smaller, quieter moments. A colleague (upon whom I will one day call to testify to the superiority of DTS) alerted me specifically to the subtle whooshes of the bullets underwater; via the Theta, these were not only clearer but more discernibly 'directional'.

Turning to less effects-laden soundtracks, the Theta revealed deft handling of music-plus-dialogue-plus-sound effects through the early fight scenes in , most of the action scenes inand during the nightclub sequences in , the sound moving from authentic 1940s Big Band-plus-vocals to crashing glass. Undoubtedly, much of the credit goes to the processor, but that is true in any system, and so it is in some ways difficult to separate the two. Which is why I schlepped 45kg-plus of amp into my 'purist' room. Wired to the Wilsons and fed purist analogue and digital signals (Theta's new slogan, by the way, is 'Digital Done Right', my italics...), the Dreadnaught suddenly turned into a world-class stereo amplifier.

But, hey, you're thinking, why didn't I just go two-channel in the main system? I did, I did - switching the Lexicon to stereo and with the Theta's surround bus deactivated, and it did sound wonderful. But that was in single-ended mode, remember? In the purist system, a quick burst revealed the immediate and obvious superiority of the balanced mode, a digital SPL meter ensuring that I was hearing no level gain. In addition to making me beg for an XLR-equipped Lexicon, the experience revealed whole layers of low level sound, the sort of subtleties usually denied most A/V systems...if for no other reasons than two-channel music-only sound spares us the distractions of extra channels, visuals, the typically louder playback of a movie-viewing system and, typically, inferior ancillaries.

'Crowdpleaser' on the Lightning Seeds' latest, most of Lenny Kravitz's , even Cher's 'Believe' are close to presenting a two-channel mix of cinematic complexity in that they blend voice and synthesiser, real instruments and artificial. Theta applied the same even hand to the music-only diet as it did to the vids, amusingly providing a silky sheen to the music not unlike that of the finish of the front panel. It was 'easy listening' in the non-MOR/schmaltz sense: 'easy' in that it was effortless, fatigue-free.

But for me, it's a tragedy: too many of you in the market for a robust, fearless, big-bucks tranny amp won't even have the Dreadnaught on your short-list if A/V isn't part of your plan. Me? I think Theta's Dreadnaught is one of the finest solid-state amplifiers I've heard, the number of channels be damned. If I had to give up valves, or house only one system, this is the amplifier to which I'd aspire. It's a ******g masterpiece.

Absolute Sounds, 58 Durham Road, London SW20 0DE. Tel 0181 971 3909, FAX 0181 879 7962

Sidebar: Stereo Vs Surround!
While most of the connections are obvious and self-explanatory - choosing between single-ended and balanced is now a fairly commonplace decision - the stereo vs surround bus selection needs clarification. What Theta has fitted is a switching facility which allows you to use only the channels required for your type of listening. It is this feature which got me to thinking about how meaningless are the divisions between A/V and pure music playback, Theta having shown that, wasting electricity aside, one amp should fit all. What you do to access this feature is to simply connect the main left and right speakers to terminals with their toggles set to stereo, while the remaining channels - centre and rear left/right - have the toggles on their modules set to surround.

When you switch on from the front panel (this amp needs a long warm-up time, so leaving it in standby when not in use is advisable, rather than switching off the rear panel rocker), you can simply choose the stereo-only speakers or both. If the thought of pressing two buttons to activate all five channels troubles you, note that the selecting action can be triggered remotely by the use of a suitable control unit, e.g. Theta's Casablanca or Casa Nova - not ust overall on-off, but either/or, stereo or surround. The benefits, especially for purists, are the elimination of unused channels during stereo-only playback and the sonic remuneration this might contribute, and the green effect of using less AC juice. According to Theta's specs, the Dreadnaught consumes 750W in 2-channel mode, but 1440 in 5-channel mode, so the difference is conside
rable.

Additional Resources
• Read audiophile power amp reviews from the likes of Krell, Mark Levinson, Audio Research, Linn, Naim, VAC, VTL, NuForce, Pass Labs and many others here.
• Read about tubes on the Audiophile blog, AudiophileReview.com.
• Want to read audiophile stereo preamp reviews? We have dozens from brands like ARC, Krell, Classé and many more.
• In the market for audiophile loudspeakers? Here are over 100 reviews from brands like Wilson Audio, THIEL, MartinLogan, Bowers & Wilkins, PSB, Vandersten, Magnepan and many more.

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