Reviewer: Srajan Ebaen
Source: Zanden Audio Model 5000 MkIII DAC; Accustic Arts Drive-1
Preamp/Integrated: Bel Canto PRe2
Amp: AUDIOPAX Model 88
Speakers: Anthony Gallo Acoustics Reference 3; nOrh SM6.9; Artistic Audio Möbius [in for review]
Cables: Stealth Audio Varidig S/PDIF, Stealth Audio Indra (x2), Crystal Cable Reference speaker cable and power cords; ZCable Hurricane power cords on both conditioners
Stands: 2 x Grand Prix Audio Monaco four-tier
Powerline conditioning: BPT BP-3.5 Signature; Walker Audio Velocitor for source components
Sundry accessories: GPA Formula Carbon/Kevlar shelf for transport; GPA Apex footers underneath stand and speakers; Walker Audio SST on all connections; Walker Audio Vivid CD cleaner; Furutech RD-2 CD demagnetizer; WorldPower cryo'd Hubbell wall sockets; Musse Audio resonance dampers on DUO subs; Mapleshade 4" solid maple platform under BPT conditioner
Room size: 30' w x 18' d x 10' h [sloping ceiling] in long-wall setup in one half, with open adjoining living room for a total of ca.1000 squ.ft floor plan and significant 'active' cubic air volume of essentially the entire (small) house
Review component factory-direct pricing: 999 Euros delivered without Q-controller, $1,298 with Q-controller

The eAR Pre Two by Danish firm Acoustic Reality arrives in a very unusually shaped small pyramidal enclosure of bent stainless steel, with a triangular footprint, a black rear panel and a keyhole for wall-mounting which then faces the connection bay and controls to the floor. 9.25" along the longest edge of the rear, 8.75" wide on the bare front and 6.5" on the side with the attenuator and company nomenclature, maximum height is 5" for a compact, stylish component that spells Scandinavian chic in capital letters. A unique optional feature installed on this review loaner was the Q-controller. It was accessible as a second set of pre-outs preceded by a proprietary circuit whose parameters are adjustable via dual-mono trim pots to alter the Q or damping factor of sealed-alignment loudspeakers (ported designs should first be sealed with a foam plug to optimize this feature). An outboard 17-Volt DC wall-wart power supply connects to the rear panel via 5-pin DIN and a 6' umbilical. With the Q-controller installed and as delivered for review purposes, the Pre2 was limited to two sources since it converted one possible input into a second output with inverted phase (the regular pre-out is non-inverting). However, when ordered with the Q-module installed, the Pre2 sports one Q'd pre-out and three inputs standard.

The name Q-controller could be misunderstood as pointing at amplifier damping factor which is an audiophile buzz word and part of the 'zero's war' of spec man silliness. It relates to the interface of source and load impedance. The lower the former, the higher the damping factor. Low output impedance transistor amps have a far higher damping factor than most any tube amp known to man. Popular wisdom cites this as one of the chief reasons why solid-state amps wring better bass performance from most loudspeakers. In the olden days, amplifier output impedance and speaker input impedance were often closely matched 1:1. Even today, certain speakers with proper self-damping like most single-driver crossover-less designs actually don't benefit from high damping factors which over-damp to prematurely roll off LF response [see Nelson Pass' article on this phenomenon]. These speaker types often produce lower and fuller bass with tube amps. To categorically pronounce a high damping factor superior to a low one is thus shortsighted nonsense. It depends on the speaker you want to drive. The Audiopax Ref100 for example is specifically designed with the distortion and impedance characteristics of SET amps in mind.

That said, the Q-module actually alters the operative damping factor or Q of the speaker by implementing an adjustable version of the Linkwitz-Greiner theory. It works over the range of 0.1 to 1.0 and applies some sort of tailored bass boost once you drop the value below a Q of 0.7. That will enhance transient response but reduce output by accelerating roll-off and thus require 'equalization' and more and more amplifier power depending on the size of the speaker enclosure. Though I couldn't truly understand the designer's technical explanations on the phone due to the Danish/English language barrier, he essentially dubbed this feature an "analog room correction without phase shift". He claimed that a customer of his sold a TacT room correction device and now obtains better subjective and measurable results with his Q-controller augmenting 15" woofers in his speakers. To the designer's knowledge, this Q-controller is the first commercial adjustable implementation of the Linkwitz-Greiner theory. Another Danish company does sell a similar module, albeit with fixed values that become invalid as soon as the room, the speaker or the position of the speaker in the room changes.

To really test this Q-controller feature, I'd have to abandon my usual active horn references and rely on the passive Anthony Gallo Acoustics Reference 3s (10" air-suspension woofer), the Artistic Audio Möbius (8" ported woofer) and nOrh SM6.9 (7" ported woofer). To boot, I'd use Roger Hebert's Wyetech Labs Sapphire paralleled 300B zero NFB monos for 18 watts of 'wimp power'. Common wisdom would wag a finger and predict underpowered, under-damped and not at all kosher for any of these 88dB lads - unless you were a deftly daft reviewer of course. But hey, what a setup to stick it to conventional wisdom if Lady Luck fancied me. And would I really be dumb enough to set you up this way and then fail to be lucky?

Certain audiophiles complain about never getting any. Wyetech Labs' new monos might contribute to this dry spell by keeping you locked away in That Room of yours. Still, you'd be getting something else highly satisfying if less carnal. And even without any wizardry by James Bond outfitter Q, malnourished, wan and pale would be the last words on your mind. Twirling the remaining hairs on your neck, you'd be listening to the above rig in a flummoxed state of mind. The eAR Pre2 not only has oodles of gain up the proverbial ying-yang but also adds a fetching amount of body and color already duly noted with the Duos over the standard outputs. 'Color' is a dangerous word in our audiophile lexicon. Let's be clear that I'm not using it to suggest colorations but rather, the opposite of 'black & white' or the byproduct of body which gives contrast and richness to the sound. My reference Bel Canto Design PRe2 is not bodylicious in the same sense. It's smooth yet very bland if you expect additive behavior from your preamp. Like me, you could also view it as a paragon of neutrality - designer water without any discernable self taste. In my resident system with its tubes in the DAC and monoblocks plus the latter's TimbreLock facility, that's exactly what I want in a preamp - nothing except for superior noise floor, heightened resolving power and creature comforts like remote control, input-specific volume memory and the like.

However, that preference is clearly system- and taste-dependent. Some rigs need help in the grunt and heft department. Others are flat and need more 3D. Acoustic Reality to the rescue. Their Danish preamp acts more like a tube pre in this regard. It sticks the music into the gym for a quick workout and has it exit moderately pumped and flushed. This is true for the regular and the Q outputs (which usually wouldn't both be on the same unit but were deliberately installed in parallel to enable this comparison). Still, swapping between normal and Q links (remember to invert phase at the speakers in Q-mode), quickly made clear that this adjustable feature was no mere marketing gimmick or designer fluff. With the Gallos, it did exactly what the word on the street predicts about higher amplifier damping factors in general. It added articulation, pitch definition and displacement down low. In one word, it inserted the iron fist of control and paid back with better transients. Sometimes common wisdom isn't so common after all. Experimenting with all sorts of music that would benefit from more rather than less control, I soon began to view the Pre2 with Q as a spectacularly well-matched compadre for my kind of amplifier which, as a general rule, is weakest in the lower frequencies when driving speakers not particularly designed with SETs in mind (i.e. 99% of all available speakers).

Where common wisdom would be wrong? Writing a blanket indictment against an 18-watt SET driving 88dB speakers with massive 10-inch woofers while citing poor or at least compromised results as justification. Not. As the upcoming review will show, the Sapphires are anything but wheezy SETs with raisins for cojones. Still, like others in their category, they do suffer two apparent shortcomings - low power and relatively high output impedance. While there can be no argument about these attributes, what they should signify is very much up for grabs. And the Q-controller shifts this scenario even farther left field than predictions would have it. This feature clearly doesn't affect the operative output impedance of the amplifier which is what the speakers see. It also doesn't affect the Pre2's output impedance which remains 75 ohms regardless of Q-controller setting. This is not an impedance-contingent effect despite the suggestive name. Still, I can unequivocally report that it works as advertised. The most fascinating aspect when used with a SET is that the tonal/textural qualities in the bass don't change at all. What changes is firmness and slam. In broad strokes, think solid-state quantity, tube quality. And that's an exceptionally welcome combo in my book.

Time to see how the 88dB Artistic Audio Möbius speakers would react to being Q'd. Back went the Gallos into our modest home theater rig sans center or rear channels.

Due to its native port resonance, the Möbius responded rather critically to exactly where the Q-controls were set. Had I used something other than a low-power amplifier, I couldn't even have run the speaker in this fashion without first stuffing its vent to control the acoustical parameters of the box. At 0, bass was overdone and a little out of control - slightly fat, slightly fuzzy, slightly bloated and indistinct. Cranking the controls to full blast would have elicited applause from the "cellulite be gone" telecommercials of magical potions and lotions. The bass clearly firmed up and regained its composure. It didn't become the equal of the Gallos but when compared to itself, was a significant improvement nonetheless. Things got even better when I stuffed the ports with rolled-up cotton pillow cases. Extension decreased somewhat but edge definition and tautness improved. Setting the controls back to 0 meant a return to minor unruliness but not as pronounced as before. Running the speakers subsequently from the normal outputs and again with open ports as designed was a step backwards in control but regained some reach when compared to the stuffed ports. The latter test would have required far more amplifier power to regain or even improve extension over what was lost by lowering the enclosure Q via the preamp's controls. In the final analysis and referenced to my Reference 3s, the Q feature seemed somewhat less useful with the Möbius when using a low-powered amp. Little surprise there. But I had one more ported speaker trick up my sleeve: The Thai cast-marble and turbine-shaped SM6.9s.

With Q=0, the woofers now nearly jumped out of their fluttering skins, not quite as bad as hitting infrasonic vinyl without a low-pass filter at 30Hz but clearly completely out of control and frightening. Set to max however and with their little butts plugged, the damping factor feature was clearly preferable to running these speakers from the normal outputs. Needless to say, there's quite a range of adjustments but they'll be different from room to room and speaker to speaker so I didn't bother to go anal outside of confirming the extreme options. For a real mind blower, I then set these babies on the floor, angling them upwards to make up for the loss in height. Close floor proximity can do wonders for this type of speaker, something Mapleshade guru Pierre Sprey has been preaching for ages. He had it proven to one and all during HE2004 in the Robyatt Audio room. A pair of Fostex-based single-driver speakers from Omega perched sideways on Pierre's maple buttresses, hovering within a foot from the floor while dishing it out. This caused our own Jim Bosha and colleague Art Dudley to flip their wigs and pronounce this exhibit one of their favorites. While not nearly as resolved, extended or dynamic as the Gallos, my $995 pair of thick-wall 2-ways without any internal stuffing majors in a fun quotient similar to that Robyatt/ Omega rig. Think perky and meaty presentation that belies size or price.

In the end, Acoustic Reality definitely is on to something very useful with their version of gizmo king Q, particularly if you run air-suspension/sealed loudspeakers with triodes. What if you don't? Consider the Pre2 regardless. While aftern real estate forbids the use of silly garden-hose cabling, the sonics will bring a smile to your face. This is a component with character rather than overt voicing. It doesn't mess with tone but injects a very benign presence of full-blooded heft that tends to completely elude passive preamps. It makes a strong argument for using a preamp even if functionally you could get away without one. Don't let the wall wart power supply and petite size fool you. This is a serious piece that gives you certain tubular benefits without the usual heat, price or upkeep. The state of Denmark scores a big one with this good li'l 'un on the value/performance charts!

I was less enthralled with the matching triangular amp previously reviewed, particularly with its lack of protection circuitry and its reliance on Speakon connectors jammed into a very inconvenient space-challenged recess (both of which, I'm told, has been addressed since). I'm thus very pleased to report that the preamp sibling suffers no apparent cause for redesign and is a winner just as it is. Additionally and somewhat bucking the relentless trend to go upscale that dooms our industry in general, its asking price of 1,298 Euros with the Q-controller seems very fair. For those wishing to go upscale, pure silver wiring and fine silver RCAs, active crossover functionality and a massive full-size outboard power supply are some of the add-on options offered inside the very same physical package but then dubbed Pre Extreme or Pre One. Well done, eAR!
Manufacturer's website
US distributor's website