Tube Preamp Reviews

No preamplifier, no cry
Short a preamplifier, I drove the VTL 300s with the EAD straight out for CDs while for analog I resurrected a Dynaco PAS-2 I'd picked up at a garage sale for $5 (along with a Stereo 70 fitted with Amperex "Bugle Boy" EL34s and a mint Scott 350 stereo tuner thrown in). All four gold-pinned Telefunken 12AX7s in the Dyna passed Tube Testing 101, and the unit wasn't spitting any DC nasties, so I cautiously inserted it into the system, replacing the Clavis with a $125 Grado Signature Jr. cartridge (nice!). Hello vinyl, bye-bye neutrality. But for five bucks, what the hey? It's no mystery why Dynaco sold about 100,000 PAS 2- PAS 3- PAS 3x preamplifiers. They were cheap and they were damn good.

But not good enough for my needs in 1995. What to do? I borrowed a friend's Audio Research SP-11 Mk.2 for a spell, but finally I decided what I needed to do was buy an Audible Illusions Modulus 3. Seeing as how I'd recommended it without reservation in TAS based upon hearing it in other people's systems, and given its very reasonable price (then about $2000 with moving-coil phono board), it made sense.

I give you a short history because this is my first electronics review in Stereophile, and I hope the added perspective will lend more gravity to what you're about to read.

No more history
While Audible Illusions hasn't sold as many preamps as Dynaco did in its David Hafler heyday, more than 15,000 Modulus preamps have flown from the factory—well, dribbled is more like it—over the past 15 years. That is an impressive number for any high-end product, especially an all-tubed one.

As my friend Tony Chiarella pointed out in his Modulus 3 review in TAS a few years ago, Art Ferris, the man behind Audible Illusions, began his audio life as a dealer in precious antiquities: vintage McIntosh and Marantz gear which he exported to Japan in great quantities. So blame him if you can't find or afford the stuff.

When the supply began to dry up in the early '80s, Ferris, trained as a graphic designer, began marketing Audible Illusions' original Modulus preamplifier overseas, hoping to whet the Asian market's appetite for American tube gear.

Eventually Ferris took control of the company in an effort to improve production, quality control, and the budget-priced product itself, which had already garnered a series of favorable reviews worldwide (including JGH's footnote comment in Stereophile in October 1984 (Vol.7 No.6, p.51), that "the Modulus is a steal at its modest price") and a loyal following in the then "audio underground."

Ferris's electronic tinkering gave way to serious design chops, cheered on by the likes of Saul Marantz, the mysterious John Iverson, John Curl, and others. Over the last decade, the Modulus evolved into the Modulus 2, which underwent biannual revisions until 1992. Then it was replaced by the Modulus 3, which sold for $1495 complete with an all-tubed MM/high-output-MC phono-stage. Add $500 for the optional John Curl-designed solid-state low-output MC Gold Phono Board.

Modulus 3 arrives: the 3A waits in the wings
The Modulus design philosophy "simpler is better" is reflected in both the circuitry and physical layout. The compact, two-piece 3 arrived last winter, giving me my first opportunity to carefully examine the build quality. Looking at and touching the solidly constructed anodized aluminum (Ferris insists on nonferrous) main chassis, you'd never suspect the Modulus 3 was a "budget" preamplifier.

The faceplate is a substantial, ¼" thick, finely finished metal slab; the four meaty control knobs are beautifully machined from aluminum. The top cover is secured with nicely finished hex-headed screws. Connector layout on the back is spacious; it's easy to access the first-rate Teflon-dielectric, machined RCA jacks that are bolted to the chassis and hard-wired to one of three circuit boards inside. The rear complement includes two sets of main outputs for easy bi-amping.

Front-panel layout is simple, too: source selector (a generous six inputs), tape monitor, and dual volume controls. Two pushbutton switches flank the knobs: low-frequency filter and stereo/mono switch on one side, Mute and On/Off on the other. A nondetachable umbilical cord connects the main chassis to the hefty power supply, which is housed in a 5" W by 3½" H by 10" D chassis.