More than a few learned colleagues regard dCS converters as the finest digital processors money can buy. Sensitivity to this fact, though, shouldn't impress the observer: every brand, however awful, has a fan base, if only the designer's Mom and Dad. dCS, though, managed to acquire King Of The Hill status while being both embarrassingly low-key hideously expensive, the latter usually enough to inspire a following, the former mitigating against it.

Like the Elgar which set everyone into worship mode, the new - and far less expensive at £5000 - Delius is a 24/192 D/A converter with clean, clutter-free, slope-free styling to match the Purcell Digital Upsampler recently reviewed by MC. (Elgar, Delius, Purcell - surely the next dCS triumph must be named Lennon?) Its 460x405x65mm (WDH) case features a mix of satin and matte finishes, with a black glass top plate. dCS struck a nice compromise between the grim utilitarianism of studio gear and the frippery of fashion-dictated audio styling, the centre panel and lucid display given prominence by being a taller, separate housing. The four tiny buttons - power, input select, mute, and function select - have a luxurious feel and short travel, while the back is filled with pro-grade connectors. It's an ideal duality if you crave a balance between domestic ergonomic and aesthetic acceptability the fitness-of-purpose of studio gear. Weighing a substantial 9kg, the unit oozes confidence-inspiring quality.

A fully-loaded, obsolescence-defying converter, Delius is also a proper digital pre-amplifier by virtual of six inputs and digital volume and balance controls; keep this in mind when judging its price, because it two components in one. Volume and balance can be accessed through a front panel rotary control, or via remote. Both the balanced and unbalanced main outputs are fully buffered and may be used at the same time, with maximum output levels of 2V or 6V selectable through the Function Menu.

Delius' heart is the discrete, proprietary dCS Ring DAC, a version of the DAC seen in the Elgar, with 5-bit/64 times oversampling architecture that 'avoids the limitations inherent in the conventional one bit and multibit off-the-shelf converter ICs that are the basis of most other D/A converters.' It boasts greater linearity than conventional DACs and a resistance to degradation over time or due to temperature variations. Its sample rates are 32, 44.1, 48, 88.2, 96, 176.4, and 192kS/s, with 24 bit resolution, and the device benefits from software and hardware upgrades (from a PC, via rear-panel ingress). Amusingly, it's a development of A/D converters they produced for airborne radar, where the A/D can be a major limiting factor in the overall performance of the radar. I loved this bit, regarding dCS' non-hi-fi pursuits: 'Only the best will do. Anything less and you risk being blown out of the sky.' As opposed to merely being blown away.

Blessedly, and to allow space in this two-page allocation for other than a mere litany of operational specifics, the unit comes with 60pp owner's manual and a laminated flow-chart similar to the ones found with the more complex A/V processors on the market. And you need to keep both nearby for the first few weeks of use, the lamination providing the same life-extending properties as plastic-coated recipe cards. There are, for example, 27 categories under the 'Function' heading on the chart; trust me, you will consult it often.

In terms of 'customisability', this thing seems limitless. The function menu, either through the front panel buttons or via remote, allows you to tamper with more than any tweaker has a right to expect. Four selectable reconstruction filters are available for each sample rate, affecting the frequency response in the ultra-sonic region above 20kHz. Juggling the gains, you can enjoy an improvement in stereo imaging 'at the expense of a slight increase in aliasing', the latter manifested by a not-entirely-unpleasant increase in brightness in the sound.

Delius can mute and 'unmute' instantaneously or gradually. As dCS points out, when justifying what might seem about as necessary as an electric carving knife, that 'Ramping the volume is generally more pleasant to the ear, but in some cases an instantaneous mute may be preferable, for example when carrying out listening tests where the ramping volume levels could be distracting.' Ditto for the display brightness control, which allows the display to match the ambient light level in your listening room or to switch it off completely. For year, purists have argued that display illumination affects the sound, while those more concerned with merely aesthetic considerations might simply prefer not to have a bunch of numbers glowing during a listening session because it's distracting. Either way, the choice is yours.

dCS believes that the quality of the Phase Locked Loop (PLL) Bandwidth has a major influence on the overall performance of a D/A converter. To ensure that the high accuracy of the dCS Ring DAC is not compromised, dCS designed a discrete PLL and clock recovery circuit with two selectable settings: 'Narrow' sets the PLL turnover frequency to an extremely low value to ensure excellent jitter rejection, optimising performance with high quality sources. The 'Wide' setting provides a higher PLL turnover frequency, for 'the playback of high jitter sources that might otherwise be unusable'.

When the Delius is switched off, all settings, including volume, balance, digital filter, mute speed, display brightness and others are saved in non-volatile memory and are restored at switch-on. Also at switch-on, a rigorous self test on its digital processing is performed automatically; it also continually analyses the input signal and flags errors if they occur for easier trouble-shooting. The Delius has four de-emphasis settings, the unit de-emphasises according to codes in the input data. Also available are manual selection of 50/15µs, which was used on some early CDs, CCITT J17, which is a broadcast radio standard, and the option of no de-emphasis regardless of codes in the input data.

DCS feels that the first two modes hold special interest for audiophiles, as they enable the Delius to deal with any CD, whether or not it was recorded with pre-emphasis and whether or not the emphasis identification flags in the data stream were correctly set when the CD was mastered. Because the de-emphasis is performed digitally, the filter curves are extremely accurate. Furthermore, digital de-emphasis filters ensure that it will be easy to update the Delius to accommodate any new digital standards which might require de-emphasis, as opposed to DACs where de-emphasis filtering is implemented in the analogue domain, thus requiring potentially expensive hardware and software updates. The Delius can, for example, already process the Sony DSD format; it is, after all, based (like the Elgar) on hardware similar to the professional dCS 954 D/A converter found in major studios, which has had DSD processing capability since May 1998. But, because there is currently no consumer interface for DSD, this function is not yet accessible; once the standard emerges, dCS will release an upgrade.

One quickly determined preference was the use of XLR AES/EBU connections between Delius and the Purcell upsampler (with which I fell in love...), with RCA coaxial from my transport of choice, the Marantz CD-12. The Delius (and Purcell) were fed, both with and without pre-amps, to the McIntosh MC275 commemorative edition, Unison Research Smart 845, and Musical Fidelity Nu-Vista 300 power amps, while Wilson WATT Puppy 6 speakers were used for monitoring throughout.

After a suitable warm-up, the listening began. And it was the cause of immediate confusion. Quite evidently, I was hearing digital source material played back with a previously-unattainable level of clarity and - more importantly - warmth, the latter aspect (and only the latter) reminiscent of the late, lamented, all-tube CAL Tempest II. Such an audio satori is rare, while twice in a year is miraculous and I'd had two in the previous four months: Wilson WATT Puppy 6 and Theta Dreadnaught. This was too much. Utter seamlessness from top to bottom, precise resolution of the finest details, transparency to rival the character of a full-range electrostatic speaker, transient attack with absolutely no overhang, total freedom from digital nasties...the list of benefits was even greater in number than the catalogue of Delius' features.

Left in the demo pile from a previous session was the sublime soundtrack to on conventional Virgin America CD, which I use to remind me of why I love Classic Records' 96/24 DVD version. Even without the benefit of upsampling, the CD now aped almost completely the scale and extension of the DVD version, while exhibiting slightly more warmth. When the Purcell was added to the system, the gap all but disappeared, and it was nearly impossible to tell the difference. Refinement is but a part of overall tune-up applied by dCS. Of far greater worth, especially if you are honest and want greater realism, is a restoration of the very richness which some believe digital bleeds from the music.

Turning to solo vocals, 'unplugged' material and even wholly synthetic works, different virtues were made evident; after all, orchestral grandeur has little to do with Dr John's solo piano recordings or a session with the Persuasions' a capella. I suppose that the most singularly impressive and convincing aspect of playback through the Delius was a sense of palpability, a sense that the images weren't just three-dimensional but also possessing mass. It is, by any definition, what is required if you believe that the task of a hi-fi system is to replicate a real musical event in your home. Anything else is Viewmaster-flat images, like the aural equivalent of cardboard cut-outs. And I cannot avoid the obvious: using the Delius as a pre-amp eliminates whole stages of unnecessary extra circuitry and the concomitant noise and distortion an extra component brings to the table.

It opens a whole new can of worms. Maybe CD was really better than we ever knew. How sad that the requisite components - Linn's CD-12, the dCS converters, and the like - only arrived in time to show us this, just as we witness the re-classification of CD as 'obsolete'. But don't take it too hard, and wallow not in the cruel irony. If, as I, you've been building up a CD library since '83, you probably have hundreds of discs which will benefit from a dCS makeover. And then there'll be 96/24, SACD, DVD-A...