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Reviewer: Srajan Ebaen
Source: Zanden Audio Model 2000P/5000S; Ancient Audio Lektor Prime; AMR CD-77 [on review]
Preamp/Integrated: Supratek Cabernet Dual; Wyetech Labs Jade; ModWright SWL 9.0SE; ModWright LS 36.5 [on review]; Bel Canto PRe3
Amp: Yamamoto A-08S; 2 x Audiosector Patek SE; First Watt F3
Speakers: Zu Audio Definition Pro with Gallo Ref 3 SA bass amp/crossover/EQ; Mark & Daniel Ruby with OmniHarmonizer; WLM Diva Monitor with Duo 12 passive subwoofer, Alto bass amp, Pre/Passive and Bass Controls; Gallo Acoustics Ref 3.1; DeVore Fidelity Nines [on review]; Mark & Daniel Maximus Monitor [on review]
Cables: Crystal Cable Ultra loom; Zanden Audio proprietary I²S cable; Crystal Cable Reference power cords; double cryo'd Acrolink with Furutech UK plug between wall and transformer
Stands: 2 x Grand Prix Audio Monaco Modular 4-tier
Powerline conditioning: 2 x Walker Audio Velocitor S fed from custom AudioSector 1.5KV Plitron step-down transformer with balanced power output option
Sundry accessories: GPA Formula Carbon/Kevlar shelf for transport; GPA Apex footers underneath stand, DAC and amp; Walker Audio Extreme SST on all connections; Walker Audio Vivid CD cleaner; Walker Audio Reference HDLs; Furutech RD-2 CD demagnetizer; Nanotech Nespa Pro
Room size: 16' w x 21' d x 9' h in short-wall setup, with openly adjoining 15' x 35' living room
Review Component Retail: depending on trim level, from £2974.47 excluding VAT to £5953.19, plus possible surcharges for various phono board options
Radically different thinking about hifi. That's what Brit firm DNM not only promises but has in fact delivered for longer than most 'philes can remember - since 1978 in fact. DNM simply never enjoyed a big overseas presence to become better known. Their research into magnetics, slit-foil capacitors and material/enclosure effects on sonics occurred without brassy fanfare in the glossies. However, just one glance at their products or a cursory read through their website confirms that me-too isn't in Denis Morecroft's dictionary. Rather, it has cropped up elsewhere as a result of his research. Not all of this eventual mainstream adoption has gone unrecognized. For example, Jeffrey Kalt at US firm Resolution Audio is so enamored with and impressed by DNM's approach, he openly credits Morecroft with collaborating on his own amplifier:


"These efforts resulted in the Opus 21 s30 based on the DNM PA3 series of amplifiers. The PA3 is one of the finest sounding solid-state amplifiers ever produced. The design is somewhat deceptive - the schematics appear highly conventional but there are details which transform the performance. Most important is the treatment of the amplifier as a network element and the careful tuning of ultrasonic frequencies. How the amplifier handles signals beyond the audible range is more important than believed. This is not your everyday solid-state amplifier. This approach requires a sophisticated combination of measurements and listening tests that result in a highly tuned circuit. Surprisingly, these modifications are not detectable with conventional audio amplifier measurements, which are typically limited to audio frequencies. This area of research may explain much of the sonic differences among amplifiers which have similar measured performance [ from the Resolution Audio website]."
What is this area of special research? Simply put, alternating currents, when propagating through wires and PCB traces, create stray magnetic fields and eddie currents which interact with the originating signal and other metallic components in close proximity. Since 1984, DNM has championed the radical elimination of metals anywhere near electrical conduction by introducing low-mass acrylic or Perspex cases for its enclosures. This was incidentally the same year that DNM introduced solid-core wires. Locking-bayonet plastic-bodied DIN plugs extended this theme and the aluminum heatsinks of its amplifiers are shielded from the electronics by non-magnetic aluminium oxide blocks. Magnetic field effect behavior then is at the heart of DNM's design approach. This included the invention of slit-foil and then 4-pole T-network capacitors; the application of star earthing since 1982; and modular, very PC 3-dimensional daughter board assemblies. Proper application of global feedback without ultrasonic oscillation and intermodulation of out-of-band feedback
errors with the audible range are another core concern. Related are realistic rather than overkill power ratings. Current DNM designs combine surface-mount technologies with old-fashioned hand labor, the latter of the vaunted Swiss kind whereby Reson of Switzerland is licensed and contracted to build DNM's designs.


DNM's company philosophy is also very green by insisting on protecting customer investments; building for extreme reliability; and offering fully reconditioned second-hand DNM equipment which creates a growing community of DNM owners who can comfortably trade in equipment to upgrade while newbies may enter ownership with cost-effective recycled refurbs. The modular building approach further allows ready upgrade conversions which are priced attractively to insure a less than 5% depreciation of the customer's original brand investment. Even the currently en vogue cable movement to low-mass connectors and simple geometries has long been a DNM mainstay and the Eichmann approach borrows much from their work. Morecroft's very affordable interconnects and speaker cables are in fact the stuff of legend. While the mention of DIN plugs could raise the old incompatibility specter of early Naim kit which didn't interface well or at all with off-brand gear, Morecroft assures us that this is not at all the case with DNM.


DNM's preamp is called 3D and the Primus, Twin or Six power supply options determine whether the final two-box affair becomes a 3D Primus, 3D Twin or 3D Six preamp. For placement options and cable length management, an optional signal transfer board allows an amp to derive its inputs from the preamp's power supply rather than its main chassis. DNM uses the 5-pin DIN interface to carry left/right grounds discretely and low capacitance/high inductance interconnects are a must for best results. The split or dual mono volume control can be set to output a mono signal. The headphone socket is driven directly from discrete line amplifiers and suitable for 35 - 300+ ohm loads. For best performance during headphone listening, the power amp interconnect should be disconnected to override the main-out muting feature that gets otherwise engaged but apparently compromises the headphone signal somewhat. It is also recommended to disable any unused source inputs by setting their corresponding toggle selectors to off. When both optional RIAA boards are fitted, the 3D selects between either cartridge feed (any combination of moving coil/magnet is possible).

DNM's singular obsession with extreme wide-band circuit tuning has, as summed up by Roy Gregory of HiFi+ in his 1999 assessment of DNM's PA3S power amps, resulted in something "fussy eclectic and off-beat. Resolutely hair-shirt, two channel and devoid of any convenience features at all, they are expensive and in terms of material content, sadly lacking. They are also beautifully made precision amplifiers, rather than male jewelry or foundation stones for your ego. They should be measured on the scales of musical satisfaction, and in that realm they're one approach to the state of the art." In other words, forget audio jewelry, Boulder/Rowland-type tank construction, remote control and sundry creature comforts. This is uncompromising kit that doesn't romance the typical hifi punter with the usual laundry list of attributes many equate with quality - size, mass and glitz.


Incidentally, Morecroft is quick to credit superior SETs with especially treble performance and purity that is far harder to achieve with transistors. Still, his expertise with semi-conductors and associated research convinces him that if properly applied, transistor circuits have the upper hand. It's that elusive if that separates the men from the boys and includes minutiae like acrylic screws and the wonky behavior of subtle electromagnetic fields which set up counterparts to oppose the originals while invoking an audible electronic haze or congestion. Removal thereof -- what we might call a pervasive electronic signature that distinguishes playback from live performance -- has been Denis Morecroft's private crusade. It's arguably been running in parallel to the SET renaissance which is based on similar pursuits, albeit based on different technical implementations.

Stereophile's Art Dudley, a listener after my own SET/hi-eff speaker heart, had more than one go-around with DNM gear over the years. His latest one published in 2005 where he concluded that "...toward the end of the year, the 3C Primus was at the heart of a system that gave me more pleasure than any other: an all-Linn record player driving the DNM preamp, driving the Lamm monoblocks, driving the Quad ESL-989s: the best combination of musical accuracy, color, drama, scale, and texture I've ever enjoyed in my home, framed with superb stereo imaging - and all quite fun to use. The DNM once again impressed me as extraordinary in virtually every sense - and more than worth the asking price." Art then mused that "the Primus is only the entry-level 3C preamp: The others in the line, especially the new 3D, may well sound even better. And I'm told the 3D does have a mono switch." His surprised and surprising assurances to readers that the entry-level DNM preamp positively loved SET amps naturally didn't go unnoticed here. When an overture for a DNM review was made, first with us, then with DNM on our behalf and the company responded to that reader's suggestion by contacting us, I welcomed the opportunity. As subject, the new 3D preamp was proposed and I happily agreed. If its predecessor had lifted Dudley's kilt so flamboyantly, what fine things could the new 'um be accused of?
Manufacturer's website