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Reviewer: Edgar Kramer
Source Digital: Sony XA-5ES as transport; Bel Canto Design DAC 2
Source Analogue: Pro-ject 6.1 turntable with Pro-ject arm and Goldring cartridge
Preamp/Integrated: Supratek Sauvignon with NOS RCA and Sylvania tubes
Amplifier: Pass Labs X 250.5
Speakers: Wilson Audio WATT/Puppy System 6
Cables: Cerious Technologies Interconnects [in for review]; Harmonic Technology Magic Digital; Harmonic Technology Magic and Truthlink Silver; DanA Digital Reference Silver; Eichmann eXpress 6 Series 2; Bocchino Audio Morning Glory interconnect cable [future review]; PSC Audio Pristine R30 Ribbon [on loan]; Cerious Technologies speaker cables [in for review] and Harmonic Technology PRO-9+ loudspeaker cables; Harmonic Technology Fantasy AC; Shunyata Research Diamondback power cords, Eichmann eXpress AC power cable; PSC Gold Power MKII AC cable [on loan]
Stands: Lush 4-tier, partly sand filled
Powerline conditioning: PS Audio P-300 Power Plant (digital equipment only), dedicated 20 amp circuit
Sundry accessories: Bright Star Audio IsoRock Reference 3, Bright Star Audio IsoRock 4 isolation platforms and BSA IsoNode feet; Bocchino Mecado isolation diodes; Black Diamond Racing cones; Stillpoints ERS paper in strategic positions around DAC, Shakti On Lines; Densen CD demagnetizer; Auric Illuminator CD Treatment; ASC Tube Traps
Room size: 16' w x 21' d x 10'/11' h [stepped ceiling] in short-wall setup, opens to adjoining office room
Review component retail: $800/ea. unbalanced, $900/ea.balanced (as reviewed)

Lilliputian devices
Brace yerselves. The beginning of the new century finds itself in the midst of ushering in a turning point for high quality, affordable and diminutive audio amplification. The end of the previous millennium saw the emergence of digital power processing technologies for the purposes of amplifying the signal that drives our technologically rather retrograde loudspeakers. Companies like Bel Canto, Spectron, Sharp, PS Audio and TacT were early adopters and pioneers of that pubescent technology.


Some manufacturers released models sporting various versions of the Tripath digital chip that popularized so-called digital amplification while others used lesser-known digital technologies from competing companies or developed their own variations. All were stuffed into the same high-tech basket and henceforth referred to as Class D amplifiers, including amplifiers like Linn's, which merely contain switch-mode power supplies.


These amplifiers were hailed for their light weight, thermal efficiency and general technical prowess. Still, they left a large proportion of audiophiles yearning, specifically in the areas of harmonic richness and timbral accuracy. Sure, there were superior examples of this technology that did a splendid job at driving and controlling the loudspeakers in an efficient and satisfactory manner but like their operating temperature, conservative music lovers received them frostily.


However, the last couple of years have seen the emergence of digital amplification technologies that are a far cry from the previous pioneering generations. ICEPower from B&O, the latest refinements in Tripath Technologies, Cirrus Logic, Yamaha, LC Audio and Hypex are just a few of the names that have brought about improvements to the digital amplification industry. These technological advancements have given rise to numerous manufacturers like H2O Audio, Flying Mole, Sonic Impact, Red Wine Audio and Acoustic Reality. Stalwarts like Audio Research and Jeff Rowland Research too have embraced Class D technology for select models within their catalogues.

Now there is a new kid on the block that's purportedly doing things a bit different. As NuForce prefers to refer to it, the 100-watt RMS Reference 8 is not a run-of-the-mill digital amplifier but rather, an analog switching amplifier [actually true for most of the breed - Ed.]. The design is unique and based on proprietary in-house advances by chief designer Tranh Nguyen who has filed for no less than three patents, with several more pending. These folks aren't capitalizing on other companies' OEM technologies to incorporate it into their own black box with blue LEDs for a pretty penny. They are actually inventing technologies from the ground up. Good on 'em! And what of the credentials for such an ambitious project, you may wonder? None other than Nguyen's position as chief bottle washer in charge of developing the Tomahawk missile power system.
Who better to explain than Nguyen how the "NuForce™ amplifier technology is based upon the principle that a power oscillator can be modulated by an audio signal to produce an amplified audio signal obtained with a reconstruction filter but without the bandwidth limitations of a fixed frequency carrier-based conventional PWM control. It uses a high-performance analog modulation technique and a close-loop control system. Therefore NuForce refers to its audio amplifier as analog switching amplifiers".

The NuForce design philosophy includes the implementation of very high usable bandwidth with a -3dB point of 50KHz, very low distortion within the full frequency range and almost zero phase shift. Remarkably, the NuForce engineers headed by Tranh have created a 26dB gain circuit that sports the highest damping factor (lowest output impedance) I've ever come across - a massive 4000 at any audio frequency. Call me a gun jumper but shouldn't that translate to an iron-fisted grip on any unruly bass driver of any diameter and therefore a fast, accurate bass range? In addition: "Unlike the conventional Class-D amplifier, NuForce's analog switching amplifier does not require a saw-tooth waveform for modulation but uses a proprietary, naturally occurring modulating signal. In conjunction with taking the signal directly at the loudspeaker terminals to eliminate filter distortions, NuForce's natural switching signal does not add noise into the system. NuForce™ amplifiers also don't suffer from the 180-degree phase shift caused by the usual output filter".

The comprehensive NuForce website further states that the high bandwidth and unique closed-loop system provide very high forward gain well beyond the audio frequency range up to 10MHz. All non-linearities are claimed to be greatly reduced to achieve an operating power bandwidth as high as 150kHz while maintaining consistently low distortion across that spectrum. Unlike conventional or digital amplifiers, crossover distortion, excessive heat, MOSFET junction noise, phase shift, frequency jitter etc.are purportedly all eliminated.


All this technology is packaged into two plain, simple and ultra-lightweight black anodized aluminum boxes with the ubiquitous central blue LED. These minis deliver 100 watts of 2-8-ohm RMS power with 1152 watts of 2-ohm peak power that may just about fit in your trouser pockets. Not for long though. All current NuForce owners will soon be receiving a new ¼" brushed aluminum faceplate. Gratis. Quite a swell gesture from the NuForce folks. Has anyone heard of a multi-national bestowing such upgrade niceties upon their loyal customers por nada lately?

Actually, "all this technology" and then looking at the internals of these dwarfs becomes almost an oxymoron. There is not much stuff inside when compared to a conventional amplifier design with a linear power supply but what there is becomes a hi-tech testament to mind-boggling modern circuit miniaturization and surface-mount technologies. Don't be fooled by the plain external appearance. Nothing about the Reference 8s is quite conventional or mundane. Externally, each monoblock sports the bare essentials - a rear mounted on/off switch, either XLR or RCA inputs depending on your choice of connecting cable terminations (in my case XLR, a $100 upcharge) and a set of the increasingly popular and quite clever Cardas 2-in-1 rotary knob speaker binding posts. That's it. Finito. Of course, what else would you need?