Carver Silver Seven Mono Vacuum Tube Power Amplifier Reviewed

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History lessons may bore most of you, but some background is�needed to understand the brain-rattling Silver Seven. A lesson in�psychology wouldn't hurt either, because what we're looking at�here is a response to hurt pride, or ego, or whatever it takes to�drive a mass-market manufacturer to produce a four-chassis power�amplifier clocking in at seventeen big ones.

Additional Resources
� Read�more stereo amplifier reviews�on HomeTheaterReview.com.
� Find�an AV receiver�to pair with this amplifier.

Bob Carver, a wizard designer who can't decide whether he wants�to be Albert Einstein or Cecil B. De Mille, has the high end in�his blood. Founder of Phase Linear, Carver can take credit for�being one of the first to manufacturer gigantic overkill�transistor amplifiers. The seeds of cost-no-object high end took�root in the late 1960s and early 1970s, and Phase Linear was a�key player. But Bob's tenure with the company which bears his�name has seen only the production of affordable products with no�aspirations toward the high end, signified by a mix of genuine�innovation and marketing excess. Indeed, some of the Carver�notions are so bizarre as to border on the comical, but this�hasn't stopped the company from selling many millions of dollars�worth of hardware.

Carver has always enjoyed winding up the press with what are�known as 'the Carver Challenges'. Three years ago, Bob took on�the American high end community -- mainly in the pages of��Stereophile� -- by suggesting that he could make one of his more�affordable amplifiers sound just like whatever cherished�high-ender his critics cared to name. The technique he employed�was what he calls 'Transfer Function Matching', in which the�differences between an input signal and an amplifier's output are�used to identify its 'sonic fingerprint'. By inverting an�amplifier's output and summing it with the output of a second�amplifier, the amplifier can be tweaked to sound like the first.�If the two are absolutely identical, then a null will be created�by complete cancellation. Any differences will be the distortions�or by-products to be removed for tweaking the second amp to sound�like the first amp.

Subjective tests followed, apparently supporting Carver's�contention, but his victims were less than satisfied with what�reached the shops. Stung by this, Carver decided to produce his
own cost-no-object 'statement', returning to what he has�described in print as his true love: tubes.

Carver knows his target victims well enough to realize that what�he needed to produce was an absolute mother of a tube amplifier�which would offer the sound of the classics, the true greats,�while being able to emulate the virtues of modern amplifiers in�every respect. If it seems like Carver tailored the amplifiers to�perform in such a way as to appease certain reviewers, well,�that's probably the most pragmatic (if somewhat cynical) approach�I've ever heard of as far as hi-fi design is concerned. On the�other hand, if you, the reader, believe that Reviewer A is a�knowledgeable and honest individual whose opinions are to be�valued, then it also stands to reason that the designer who�builds an amplifier to that reviewer's exact tastes has made what�that reviewer genuinely considers to be a superlative product. In�other words, forget the motive, which will always be to sell�amplifiers and garner rave reviews (or vice versa). The proof is�in the performance.

Carver's Silver Seven Mono Vacuum Tube Power Amplifier is�described as a classic circuit benefitting from modern�developments. Taking no chances, Carver has incorporated every
known tweak short of Beltism, so the end user need do nothing�except install the amplifiers in the system.

The Silver Seven takes the form of two chassis per channel,�including a massive power supply connected by a multi-core�umbilical cord to an equally massive power amplifier. Starting�from the ground up, each hand-rubbed, black lacquered chassis�rests on four rubbery Simms Vibration Dampers, which in turn rest�on polished granite anti-vibration bases; Carver is taking no�chances here on mechanical interference causing microphony and�you do save on Isoplats. The power supply chassis, measuring�252x452x245mm (wdh) including the feet and baseplate, sports a�large needle-type meter on its front sloped panel, the meter�monitoring tube condition.

The slope continues back toward the massive mains transformers,�behind which lurk the fuses, the mains and umbilical leads and�the on/off and stand-by switches. This is Ergonomic Failing No 1,�because -- I don't care how purist you are -- these amps will not�be left on at all times once you've experienced either the heat�they generate or the way they set your electricity meter into�overdrive. Having the switches on the front would make one's life�a bit easier. The meter itself does diddly until something goes�wrong, so I didn't get to see it dance. It does, however, look�cute enough in its retro glory to have inspired Sony to put a�similar meter on the front of their top-end amplifiers.

Switch-on from cold takes a good three or four minutes until the�'soft start' relays click and music emerges. At times when you�wish to interrupt your listening sessions, you can switch the�unit into stand-by; switching back on takes about one minute as�the amp has been left 'idling'.

You'll know when the amps are on, believe me. Each 330x485x275mm�(wdh) main chassis sports no less than �fourteen� 6550 output�tubes, plus a 6550 as a voltage regulator; KT88s are an�added-cost optional extra. A 12BY7 high-gain voltage amplifier�pentode serves as the input valve and three paralleled 12BH7A�power triodes drive the 6550s, completing the line-up. While the�1930s-mad-scientist styling may be aimed at securing a following�in Japan, where such glorious kitsch has real cachet, seeing four�chassis and 38 exposed valves is guaranteed to seduce �anyone� who�ever looked at an out-of-date �Hi-Fi Yearbook� in a lustful manner.

Protecting the four input valves at the very front is a tiny�barrier, to the right of which rests a gain control; the mains�transformers reside at the back. Beneath these at the rear are�two gold-plated input sockets, one for real-world pre-amps and�one for pre-amps guaranteed not to leak DC. Playing it safe, I�opted for the normal rather than the 'turbo' during the reviewing�period, as I don't trust any hi-fi equipment, whatever the�pedigree. The hot-rod input is labelled 'Lab Direct' and is DC�coupled to the amplifier, while the 'Normal' input is AC coupled�through a WonderCap. In a fit of bravery (or stupidity), I gave�'Lab Direct' a bash and will admit to experiencing a shade more�transparency, but my cowardice soon had me reconnecting via
'Normal'.

Although the 'Seven features automatic biasing, a bias switch on�the back comes into play when the valves have aged to a point�where the meter shows an idling current creeping above 0.6 amps.�Switch to 'high bias' and you extend the life of the tubes, as�the plate current will fall back to between 0.2 and 0.6 amps.

Ergonomic Failing No 2 is also found on the back, another touch�of 'retro' in the form of gold-plated screw tags for the speaker�connections. The Silver Seven allows you to choose from taps of�1, 2-4 or 8 ohms, but screw heads are not that wonderful for�grasping two bare cables or even two spade lugs if you're�bi-wiring. For #17,000, though, I'd be surprised if Carver said
'No!' to a customer who insisted on five-way binding posts.

The Silver Seven derives its name from the use of silver wiring�and silver solder throughout, and seven pairs of output tubes.�Carver, eager to have this behemoth dubbed a modern classic, used�traditional fully-balanced circuit topology, massive wide�bandwidth ultralinear output transformers and the calibre of�valves which I didn't think you could find in any quantity. The�14 tubes per side are driven to produce a conservative 375W into�8 ohms, with peak current on the 1 ohm tap of 35 amps; energy�storage is 390 joules. Reading the owner's manual and the�promotional literature reveals that the unit is tailored to sound�vintage, but with such modern touches as ghostly silence, the�ability to drive hungry and awkward loads and to offer bandwidth,�slam and dynamic capabilities not realised by tube designs of the
Golden Age.

HW International left the Carvers with me long enough to allow me�to try them with speakers including Apogee Divas (2-3 ohms),�Stages (3 ohms), Celestion SL700s (6 ohms-ish) and a host of 8�ohm-plus speakers. As the Silver Sevens are unlikely to be driven�by budget components, I restricted the sources to the�Basis/SME/Koetsu Urushi analogue front-end and the Marantz CD-12�and CAL Tempest II Signature CD players. Pre-amps included the�Audio Research SP-14 and Carver's own C-19 valve pre-amp, which�I'll discuss in detail next month.

Read more about the Carver Silver Seven on Page 2.

HTR Product Rating for Carver Silver Seven Mono Vacuum Tube Power Amplifier

Criteria Rating

Performance

5

Value

3

Overall

4

Disagree with our product rating? Email us and tell us why you think this product should receive a higher rating.


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The Sound Of $1650-Worth Of 6550s�Price shouldn't influence a reviewer or a civilian listener when�assessing any product; it should only determine the final�value-for-money rating and whether or not it fits a budget.�Although the Silver Seven may not be the dearest amplifier on the�planet, it's the costliest I've ever used in my review system and�it took a bit of effort to force myself into dismissing the�influence of the price tag. Then again, I wasn't presupposing

that the 'Seven would be all that marvellous, because I wasn't�expecting the performance to match the overwhelming appearance or�price tag. After all, Bob Carver's main achievements have been in�the middle market, and I had no reason to believe that a slap in�the face from the US press was enough to drive him to levels of�sheer brilliance.

Boy, was I wrong. Even before the 'Seven had driven the mercury�up a degree or three, I was finding my face locked in a�grin/rictus. All of those 'chill factor' criteria were met, the�amplifier delivering a flood of 'you are there' touches of the�type that would have J Gordon Holt hopping with glee. Aside from�imagining Bob Carver with a balloon over his head reading 'I told�you so', the Silver Seven -- regardless of the speaker to which�it was attached -- proved itself to be audibly superior to any�amplifier in my arsenal or in recent memory. But before I get to�the inevitable caveats , let me try to describe what this�amplifier does for the music.

However 'classic' the sound is meant to be, it has lower�registers unlike any vintage valve amplifier I can recall. Modern�designs I've heard (regardless of their chosen technology) which
approach or match the Carver include the larger Audio Research�amplifiers, most of the Krells, the big Rowlands, the Mark�Levinson monoblocks and the Goldmund; note that none of these are�'inexpensive', so such low-end control and extension does not�come cheap. If the bass does betray either its tube origins or�Carver's avowed intentions, then it's only through a slight�richness which absent from the solid-state designs mentioned�above.

The vice-like control and the richness continue with absolute�consistency up into the midband, where the latter starts to fade�out in exchange for greater neutrality. I don't know how�deliberate is Carver's sonic 'tailoring', but he managed to make�the richness dissolve by the point where it's already stamped the�sound with valve status, at the same time not allowing it to�intrude into the all-important midband. The inaccurate (though�undeniably pleasing) extra warmth heard on acoustic instruments�and vocals played through vintage tube products is absent in the�'Seven's performance -- a good thing as more and more time passes
from the days when most audiophiles lived with vintage gear and�would be prepared to forgive such euphonic distortions.

As for the treble, it's the same recipe: transient attack to�rival the fastest, most authoritative solid state devices you can�name, with the sweetness (but not the tubby lushness) of the tube�legends. However much it strikes me as dealing with mutually�exclusive virtues, Carver has managed to juggle the old and the�new with greater skill than I've yet experienced. Just as�impressive as the tonal neutrality, though, is the manner of�presentation, for the Carver has holographic capabilities�(dictionary rather than 'Sonic Holography' definition) on a par
with the very best.

'Tall', 'wide' and 'deep' are only part of the story. The spatial�characteristics also include uncanny precision and a seamlessness�that avoids overetched, 'Viewmaster'-style landscapes. In this�arena, the 'Seven has a few rivals bearing Audio Research, Krell�and (when they're working) Jadis badges, so the Carver hasn't�really pushed the boundaries in 3D terms. But rest assured that�it's world class. But if it is compromise or weakness that you�need to read about, then I should mention the way the Apogee�Divas (not the Stages) rendered the 'Seven a bit breathless.

Whatever the power rating, this amplifier is not the gutsiest�beast I've ever used. While the Diva was the only speaker in my�possession to expose some limitations in the Carver's dynamic�capabilities, I have knowledge of a few dozen other speakers�which are just as demanding. True, they, too, could be avoided,�but all are natural candidates for the 'Seven. Indeed, the�majority of high end speaker builders assume that their products�will be mated to powerful amplifiers. Normal levels were no�problem, but playing hardball is not this amplifier's forte. The�Aragon 4004 at 1/10th the price offered greater levels and no�compression or clipping with demanding material like large�orchestral works and sonic showstoppers.

But that doesn't stop me from regarding the Silver Seven as one�of the very finest amplifiers money can buy. The big chuckle,�though, is the price, which means that the Silver Seven is as�much a marketing tool as it is a hi-fi statement, however�undeniable and real its standard-setting virtues. Which leads us�to...


'T' Is For Tiny
Earlier in this review, I mentioned Carver's 'Transfer Function�Matching'. Quite obviously, the #1900 per pair, solid-state�Silver Seven T monoblock is conceived to be the poor man's Silver
Seven, right down to the 'steam punk' styling. Somewhere, I read�or heard that this amplifier was supposed to deliver '90% of the�Silver Seven's performance for 10% of the cost'. Hmmm...

Rated at a 550W per side, the Silver Seven T is said to duplicate�the 'transfer function of the Silver Seven'. Using Carver's�Magnetic Field design circuitry, it actually pumps out more�watts, can drive 2 ohm loads, weighs only 7.2kg per side (as�opposed to the Silver Seven's 68kg), takes up floor space of only�370x292mm and looks just as wonderful. The controls are limited�to an on/off switch at the front, while the rear sports the�five-way posts I wish were on the Silver Seven.

This amplifier is notorious for having received one of the worst�reviews ever published. I think I understand why, though the amp�is by no means ready for display at Crufts. Basically, Carver was�silly for hyping this as a poor man's 'Seven because even those�who haven't heard the 'Sevens would therefore expect something so�far beyond the 'norm' that the wee Carver would have had to�perform miracles. Inevitably, the 'T lacks the absolute�transparency, the delicate treble, the coherence and the�authority in the lower registers of the 'Seven, but none would�have minded so much had Carver not declared it to be a�near-clone. Indeed, it has exceptional stage width,�better-than-average depth, reasonable bass extension and -- with�certain cone-type loudspeakers at least -- enough slam to suggest�that its power rating is indicative of its performance.

However poorly it fared with the Diva, the 'T worked nicely�enough with the Stages to make me wish that I hadn't (1) reviewed�it side-by-side with the 'Seven and (2) heard Carver's claims.�And I could only register dismay when the 'T failed to prove�adequate when asked to drive the ATC SCM20 'mini' monitors. I'd�rather not dredge up the hoary old debate which started with�Carver's Cube of some 10 years back, with its astronomical power�ratings and about as much guts as Charles Hawtrey. The 'T, also�endowed with 'Magnetic Field' technology, also seems to perform�less like a 500-watter than one would expect. It simply lacked�the slam I associate with amplifiers from the Aragon 4004 on up.

But I can't trash the amp because I did manage to find speakers�with which it mated beautifully, the Monitor Audio Studio 10 for�example never causing the 'T to turn harsh or to sound�'over-driven'. But just as the Silver Seven sounded like a�thoroughbred whatever the speaker, so did the 'T seem less than�authoritative through all but the smaller monitors. It suggests�that the 'T does not want to do too much work below 60-80Hz (the�effective lower limits of most small boxes), in which case the 'T�should be auditioned with this in mind.

Let's face it: The betubed Silver Seven is simply a 'dream'�amplifier. At its frightening price, it's amazing that over 50�sets have been sold. Even Carver will admit that it's a flagship,�like Infinity's IRS, designed to call attention to the rest of�the range. That both the Carver Silver Seven and Infinity IRSes�do sell is simply a bonus. But the 'T is the first off-shoot, and�it does not succeed in bringing the 'Seven Experience' to the�masses. It's simply a good, if undistinguished amplifier.

Because the 'T is so aesthetically adorable --'retro-tech' like�the Olympus 'O Product' camera or Mazda's Miata roadster -- it�will probably sell to the same people (and that includes me) who�buy 1930s styled pens or watches or cameras. But that doesn't�help those of you who want a taste of the Silver Seven's glory at�a lower tariff. For that, you'll have to wait for the forthcoming�Silver Six, or investigate the first of the company's tubed�pre-amps. Amusingly, Carver's first valve control centre is not a�high-end piece but a #950 unit within reach of the same people�who'd consider Naim or Exposure or Musical Fidelity; its high-end�counterpart will follow later.

As for that showpiece Silver Seven, well, whatever the sins or�graces of its progeny, it is simply a milestone in high-end�design. I can't flat-out say that it's the world's best amplifier
because I haven't heard every amp available (nor has anyone�else). Indeed, if anyone ever tells you that any single product�is the best of its type, be highly suspicious and change to
another shop or magazine. But I'll tell you this: The Silver�Seven, like most Ferraris, actually performs on a par with its�aesthetic presence. When you first see the four chassis, you
can't help but grin. You realise that here is a product made�truly without any constraints. It's audiophilia gone berserk.�Then you listen. After you recover, you realise that rampant
audiophilia isn't so crazy after all.

Additional Resources
� Read�more stereo amplifier reviews�on HomeTheaterReview.com.
� Find�an AV receiver�to pair with this amplifier.


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