Audible Illusions Modulus 3A preamplifier Page 5

The Modulus's one-tube/channel phono-stage obviously doesn't use the commonly implemented "cascode section" for voltage gain (two tubes run in series) because again, Ferris feels this method induces an unacceptable amount of phase shift. Yet the Modulus offers almost 60dB of overall gain (28dB phono at 1kHz/30dB line), low distortion, and outstanding S/N ratio using active RIAA equalization in combination with very low overall negative feedback.

For low-output coil cartridge fanciers, the John Curl-designed M3 solid-state gold board (circuit traces and ground plane etched in gold) adds $500 to the 3A, bringing the total cost to $2395. The gold board, with factory-adjustable gain between 22 and 30dB, is essentially a somewhat simplified version of Curl's fabled Vendetta Research phono section (single FET versus the Vendetta's dual FETs which results in somewhat higher noise, though noise, even with the lowest-output coil cartridges, is not a problem with the 3A).

More than simply a head amplifier placed in front of the phono section, the gold board is integrated into the RIAA section of the tubed phono-stage, which then has to be custom trimmed to meet RIAA specs.

All of this circuitry is driven by a sophisticated low-impedance power supply capable of wide voltage swings: the 3A is said to reproduce a perfect 10kHz squarewave and is almost perfect at 20kHz.

The Modulus 3A sounds off
So what does this new circuitry give you sonically? Well after about a week's break-in, my quibbles with the 3's performance have gone up in solder smoke. If the Modulus 3A isn't the finest-sounding (or -non-sounding) preamplifier in the world, regardless of price, it is one of the finest, and given its price, the words of Stereophile's founder J. Gordon Holt are as true today as they were in 1984: "A steal for the money."

Using a series of very demanding orchestral CDs—including a number of Shawn Murphy-engineered soundtracks, all of which are recorded using a Kenneth Wilkinson-style "Decca tree" mike setup—I compared them EAD direct out and through the Mod 3A.

The Murphy recordings, including Dances With Wolves (Epic ZK 66817 gold CD), Casper (MCA MCAD 11240), Moviola (Epic EK 52985), and Batman Returns (Warner Brothers 9 26972-2), feature stupendous bass, gigantic soundstaging width and depth, rich string tone, outstanding portrayal of inner detail, and thunderous dynamic range—none of which will come as any surprise to "Wilkie" aficionados. Any of these, and virtually all Shawn Murphy soundtrack recordings, are audiophile-quality demo discs.

Bottom line is, I was hard pressed to hear any significant differences between the EAD direct out and through the Modulus 3A. I concentrated on bass-drum impact and focus, string tone and texture, ambience, soundstaging—you name it. If I noted any consistent difference, it would be an ever-so-slight overall darkening of sound. But so slight that I noted bigger differences when changing the interconnects between the EAD's analog outs and the Mod 3A's inputs, so we're talking very minor. The one-tube/channel line-stage of the Mod 3A is virtually transparent and ultraquiet.

As for the phono input, where there can be no "direct reference," with the low-output Clavis D.C. or the new AudioQuest 7000 Fe5, I can tell you, there's more than enough gain for them to perform on a bed of utter silence. What's more, whatever bass sluggishness I noted with the 3 was gone. The midrange was as glorious as before, and the top was extended and detailed without etchiness or glare.

Large-scale dynamics were explosive top to bottom, and well-controlled, as were the small dynamic gestures that create inner detail and a sense of living, breathing music. Everything was right with the 3A referenced to my experience listening to live music—not that my stereo sounds like live music; no one's does.

For those into playing with impedance loading, the gold phono board is factory preset at 47k ohms, but that can easily be changed by inserting the desired value resistor into gold-plated pins on each board.

COMPANY INFO
Audible Illusions
7066 Commerce Circle
Pleasanton, CA 94588
(510) 463-9191
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