Audible Illusions Modulus 3A preamplifier
By Michael Fremer   •   February, 1996 What a thankless task! No, not reviewing audio equipment (though the case could be made). I'm talking about preamplification in the digital age: who needs it? The EAD DSP 9000 MK3 digital processor I'm using includes an ingenious full-resolution digital-domain volume control accessible by remote control.

Run a set of interconnects from the EAD's analog outputs to an amplifier and you're rocking. Who needs a preamplifier, with its noise-inducing circuitry, and analog domain potentiometers? Anyone with other analog sources like tape decks, tuners or...turntables. That's who. That's me. Hopefully you.

While digital products from PS Audio (the Reference Link), Wadia (the Model 17) and Meridian (the 607) contain A/D converters, which enables them to input analog signals, "digital vinyl" is to my mind and ears an oxymoron, the impassioned arguments of the Wadia folks notwithstanding. I've auditioned the PS Audio product and found it less than transparent in A/D mode, and subject to overload. Wadia claims transparency for its converter. Dare I believe? No.

Meanwhile, back in the real world
Fact is, folks who spin the black circle want analog analog, and that means a conventional preamplifier—either one with a built-in phono section or line-stage/phono-stage separates. Speaking of thankless tasks, look at what a line-stage is supposed to do: nothing. Anytime a reviewer ascribes a "sound" to a line-stage, it must be a distortion, since the job is to pass what it's fed unaltered, but amplified in volume. With a properly designed amplifier driving source available, such as the EAD, one can assess the damage done by comparing the results straight out, and through the preamplifier .

When I got started in the reviewing business, I owned a heavily modified Hafler DH-101 preamp that I'd upgraded after reading Walt Jung and Richard Marsh's groundbreaking capacitor article published in Audio some 15 years ago.

I replaced and "bypassed" every capacitor in the box with polystyrene and Teflon versions—some the size of small sausages. I replaced the hookup wire with what AudioQuest was making at the time, and the input and output jacks with gold-plated/Teflon-dielectric Tiffany connectors that were mounted to the preamplifier's top cover—the only place they'd fit. The chassis literally groaned under the weight of all the caps I wedged in there.

The improvement in sound was amazing, but to me, there's nothing more annoying than reading a product review in which a "home-brew" component is part of the reviewing chain. I needed a preamplifier readers could relate to, and besides, the Hafler couldn't take a low-output moving-coil cartridge straight in, so out it went.

The next logical step up for me and my budget was PS Audio. I owned a succession of their preamplifiers—4.5, 5.0, 5.5—all of which had many fine qualities like low-noise moving-coil sections, outstanding soundstaging, impressive image specificity, but some serious shortcomings, such as threadbare midrange, chilliness on top, and a fondness for amplifying RF. Neutral-sounding, you say?

No way. Colorations? Clearly. Colorations I had to work around in reviewing other components. Still, the PS Audios were nice pieces for the money.

Eventually I moved on to Rowland's two-box Coherence One. This solid-state preamplifier was far more fleshed out in the midband, but somewhat closed in on top and a bit fat on the bottom. It also cost over twice as much as the most expensive PS product—reflected in its build quality—but I still wasn't satisfied, especially once the EAD 9000 arrived and I could compare the sound of CDs directly out and through the preamplifier.

The last preamplifier I had in-house before leaving The Abso!ute Sound last year was Jadis's "budget-line" DPL line-stage/DPMC phono preamplifier combo—a mere trifle at $8600/pair. The all-tubed units looked and felt sumptuous, with sound to match. The line-stage was ultrasilent, and with its simple, elegant circuitry, close to neutral when referenced to the EAD straight out. But for the slightest compression on dynamic peaks, a mild sensation of tube "glow" and a bit of added liquidity, the Jadis was neutral. What it added was more than pleasant, and didn't mask vital musical information.

The all-tube phono-stage was another story: while it sounded detailed and sweet and could handle very-low-output moving-coil cartridges, it was noisy with the Clavis, the Dynavector XX-1L, and other low outputters. When the music wasn't loud, the tube rush was, despite the importer's insistence that the unit was sufficiently quiet. When I left TAS, the Jadis left my house, review unwritten. But I was impressed.