Published On: February 14, 1992

Vimak DS-2000 D/A Converter Reviewed

Published On: February 14, 1992

Vimak DS-2000 D/A Converter Reviewed

Inundated by wonderful products at hi-fi shows, I find it a miracle that anything commits itself to memory. Upon re-reading a show report a month after I've written it, I'm mortified by the unfamiliarity of half the information. A...

CD_VIMAK-DT-1000.gif

Inundated by wonderful products at hi-fi shows, I find it a miracle that anything commits itself to memory. Upon re-reading a show report a month after I've written it, I'm mortified by the unfamiliarity of half the information. A Swiss cheese brain? Boredom? No. It's just that something has to be mind-blowing -- as in what you do to an EPROM -- if its to be retained. Yet nearly a year after my first glimpse of it at the 1991 Hong Kong show, I'm still in awe of the Vimak DS-2000 D/A Converter.

Not that I get a major buzz from D/A converters. Aside from a few buttons to push or inputs the play with, they don't offer a high Fiddle Factor. They're the digital equivalent of head amps, 'black boxes' which you need but which don't really deliver hands-on fun. The Vimak DS-2000, though, stood out from the crowd because of a number of reasons, not the least being that it's also a full-function digital pre-amp loaded with facilities like multi-room capability, on-board diagnostics fed to the factory down the telephone line, modular construction for upgradeability, drop-dead gorgeous styling, build quality that suggests Geneva rather than Massachusetts and a whole lot more. But what really moved me was the company's attitude. For a first-time exhibitor, Vimak behaved like a well-established, wholly professional veteran, right down to the slick hand-out sheets, an active display with production-ready hardware and answers to every question. And they answered my first one in record time: they followed the DS-2000 with its mandatory off-shoot, the DS-1800 D/A converter-sans-pre-amp.

Additional Resources

Why is this so important? Simply because most high-end purchases are additions to systems, few people assembling a whole system from scratch. And the kind of people likely to look at stand-alone D/A converters, especially ones with four-figure price tags, probably already own decent pre-amps. With the DS-2000 selling for just under $5000 in the USA, it's a big bucks proposition; the removal of the pre-amp section could bring the cost of Vimak performance down by at least 20 percent. And the pre-ampless DS-1800 is pegged to sell for between $3500 and $4000, which puts in right into the middle of Theta and Wadia territory, but nowhere near the top of the price ladder.

Externally, the DS-1800 looks like its dearer predecessor minus the rotary controls and the bank of push buttons. Controls are limited to 'dead flesh', soft-touch buttons providing full-power-on/stand-by selection (this unit is best left in stand-by mode when not in use, rather than having it switched off at the mains, because it doesn't reach optimum performance for at least an hour), two selectors which scroll up or down through the four inputs, a phase inversion selector and two 'program keys'. In the middle of the curved fascia is a panel which illuminates to show the input you've selected, the sampling rate (32k, 44.1k or 48kHz), a pre-emphasis indicator, inversion indicator and whether you've chosen program A or B, about which I'll tell you shortly.

The four sources include normal RCA coaxial and two TOSlink opticals, plus an XLR AES/EBU balanced input (which accepts signals from certain direct broadcast/satellite receivers); either or both of the TOSlinks can be ordered as optional AT&T/ST Glass type inputs. Additionally, the RCA coaxial can be supplied as a BNC socket. All four inputs can be driven at once, but A/B'ing from one to the next isn't as vivid as it might be as there's a short muting period between selections.

The input sockets are arranged in the middle of the back panel, flanked by a single coaxial digital output (this is optional) and a choice of unbalanced (RCA) or balanced XLR outputs to feed into a pre-amp. To the right are computer-styled nine-pin connectors which provide input and output for home automation systems, home theatre use and factory diagnostics. So far, only the latter has been implemented, but future Vimak products will exploit these interfaces with full backwards compatibility.

The Vimak is a large, hefty beast quite unlike the dainty or low-profile D/A converters which seem to be the norm. It measures 4.375x17.5x18.23in (HWD) and weighs a serious 19.1kg. Available in gloss black, gloss white or silver, the DS-1800 is an imposing unit and it looks like the £2000 that it costs our American readers is a bargain. And here's where Vimak gets cheeky: there's an optional clear perspex lid available, in case you're the type who likes to gaze inside without drooling all over the circuitry. And you'll want to look inside for proof that the weight isn't all cabinetry.

Of course, the chassis does contribute to the bulk. It's fashioned from thick solid aluminium sections around a steel frame, the layout providing isolation from electrical and magnetic interference. Separate shielding is applied to the digital, analogue and power supply sections. Inside, this unit combines the best of American high end practice and the kind of high-lux finish you see in the exotica from Japan. The chassis is copper-plated for further immunity to interference. Further isolation is applied through the use of specially designed optical couplers for the converter circuitry, which eliminates any electrical connections between the analogue and digital circuit boards. A large part of the real estate is occupied by two semi-toroidal R-Type transformers (one each for the digital and one for the analogue sections) which look like they'd be adequate for most serious power amplifiers.

The heart of the DS-1800 is a Motorola DSP-56001, using proprietary software which is upgradeable via the rear panel comms ports. Digital-to-analogue conversion is 18-bit with x64 oversampling, the data filtered and resampled through a 5th order Delta Sigma processor which converts the information to single-bit format. Four single-bit PDM DACs are used for each channel, controlled by a proprietary dual PLL reclocking system claimed to reduce jitter to 50 picoseconds (RMS). The tight specifications and overkill attention to detail provided the two major boredom-dissipating aspects of Vimak ownership over other processors.

CD_VIMAK-DT-1000.gif

The first involved the two program buttons. Vimak has all sorts of unusual plans for future applications of these settings, but at present the choice of programs include standard and weighted dither. This provided lots of head-scratching because the differences were so miniscule as to be barely audible. The differences between types of fibre optical cables were drastic by comparison. It was only when I tried a cheap transport that the choice of weighted dither seemed to improve the performance by improving inner detail. Or maybe it was the other way around. Considering that it also varied from disc to disc, I figured that it was better to get on with my life by ignoring it.

The second novel aspect, marginally related to the first, involved the choice of transports you can use with the Vimak -- and it made finding a suitable budget transport diffucult indeed. After failing to extract signals from three well-respected transports, I phoned the factory to find out what was wrong. I named the offenders and designer Mike Koulopoulos registered no surprise whatsoever. He said that most transports worked with an accuracy of 400 parts per million but the Vimak would only lock onto signals which bettered 250 parts per million. Which is a crafty way of ensuring (while we await Vimak's matching transport) that all customers try the Vimak with the transport they use at home before parting with their money. And class acts always win: I used the Marantz CD-12 transport successfully in coaxial mode, while both the optical and coaxial outputs from the Krell CD player worked perfectly. And, no, I'm not going to embarrass certain other manufacturers by telling you which ones failed to make the grade because they work more than adequately with their own and most other D/A converters.

This incompatibility with seemingly lesser transports is, depending on your feelings about raising standards, either a serious attempt at forcing CD playback onto a higher plane or it's sheer conceit. I opt for the former because I hate the notion that it's better to aim for the lowest common denominator. And the results sing for themselves.

Having access to six D/A converters, ranging in price from 350 to 3000-plus, I wasn't short of fodder for comparisons. But I didn't quite expect the Vimak to massacre the opposition. Previous experience hasn't geared me to expect radical changes when going from one converter to another, with differences between like-priced or similar types often bordering on the insignificant. It is, however, easy to fall for the Audio Alchemy Digital Decoding Engine 1.0 when you factor its price into the performance, just as it's easy to sit there slack-jawed when you hear that betubed beauty from Stax. But the Vimak, which is hardly overpriced by today's standards, has The Magic.

I've always maintained that a product which is good in all areas is worthy of recognition, while one which is good across the boards yet excels markedly in one area deserves acclaim. (Failing in any areas while being brilliant in others leads us into the area of how much we'll forgive or overlook for access to the brilliance.) The Vimak revealed no failings whatsoever, enough to warrant high praise, but it also stood out in a number of key areas. And shockingly so. Which means instant greatness.

The moment I heard the first notes from the Vimak, I knew that I was in the presence of something very special. The gains in transparency, the greater sense of realistic scale, the more precise sense of a three-dimensional event -- it was not unlike changing from a small monitor to a massive panel as far as presentation concerns were being assessed. This is not too abstract a concept to absorb; all you have to do is A/B an LS3/5A with Quad 63s. You'd have to be deaf or daft not to notice the difference.

But (as any supporter of Phil Spector's Back to Mono movement will tell you), the spatial aspects and stereo performance are secondary when compared to the sound itself. What's your preference, coloured stereo or perfectly neutral mono? Anyway, the Vimak doesn't stop at VistaVision and Cinerama. Just as the scale is reinforced in all three dimensions, with texturing removed to allow for a cleaner peek into the sound stage, so is the sound stretched at both ends. The bass through the Vimak, especially with recordings where weight is essential (listen to Incognito's Tribes, Vibes and Scribes or any club/house megamixes), has no downward limits. At the same time, there's no flab, no loss of control. Vimak does not muddle the distinction between extension and quantity. Best of all, the DS-1800 avoids the Gobi-like dryness which many feel is an inescapable negative aspect of digital reproduction.

The midband benefits from the aformentioned transparency and a touch of warmth which I'd only ever heard before from CDs played through the CAL Tempest IISE. It's not enough to suggest the use of valves, but neither will the term 'clinical' cross your mind. Vocals? They're about as real as it gets, sibilance-free and benefitting from the rise in temperature. I'm almost tempted to use the term analogue. This is constant throughout the spectrum, right up to the clean, clear treble.

And it's the upper registers of the Vimak which distinguish it from any other converter I can name. Whatever the technical limitations of CD, the heavy filtering, the limited frequency response, Vimak has managed to eliminate the choppy decay of upper frequency sounds. The transients remain crisp, fast and devoid of smearing, a trait best challenged by rapid synth work. Conversely, real instruments with extended fades -- Gary Moore's introspective moments on either of his recent blues bashes will do nicely -- taper away smoothly and consistently. As an added bonus, the Vimak's optical intputs were the first of the type to better coaxials beyond any doubt.

The Vimak's revelatory performance hasn't meant the pensioning of my turntable, but it does make further resistance to CD seem more the act of a masochist than of a true music lover.

Additional Resources

Subscribe To Home Theater Review

You'll automatically be entered in the HTR Sweepstakes, and get the hottest audio deals directly in your inbox.
HomeTheaterReview Product Rating
Value: 
Performance: 
Overall Rating: 
When you buy through links on our site, we may earn an affiliate commission. Your support is greatly appreciated!
© JRW Publishing Company, 2020
magnifiercross linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram