TARA Labs Space & Time Passage preamplifier

Better known for their speaker cables and interconnects, The Absolute Reference Audio Labs (TARA Labs) has quietly branched out into electronics and loudspeakers. Their Passage is a line-level–only preamp. I actually favor such a modular approach to preamp design. Standing as we are at the dawn of the digital audio age, the breakup of the traditional preamp into separate phono and line-level stages represents a more flexible, cost-effective design approach. Systems whose front ends are heavily into digital (CD and DAT), supplemented only by such other high-level sources as analog tape, could dispense entirely with phono stages. And because 50dB of low-noise gain for a moving-coil cartridge is difficult and expensive to implement—especially using tubes—that cost saving could either be pocketed by the consumer or used to purchase a better line-level stage.

Although the Passage is intended as a "cost-effective" line-level preamp, its looks are externally and internally refined. The aluminum chassis is finished in black with redwood side panels. A total of six inputs is provided, along with one tape out and two main outputs. The inputs are selectable from the front panel, which is also adorned by volume and balance pots and a "Mute" switch. The inside of the chassis is dominated by one large glass-epoxy circuit board containing good-quality passive parts. All internal wiring uses TARA's own Space & Time cable. A small toroidal power transformer and solid-state rectification are used in the power supply. A pair of 12AU7A (ECC82) twin triodes are used for amplification. This is a low-gain tube, with only about 20% of the voltage gain afforded by a 12AX7A. But that's okay—gobs of gain are not needed in this application. The really nice thing about a 12AU7A (or a 12AT7A, for that matter) is its much greater plate dissipation compared to a 12AX7A. (Curiously, the Passage's gain specification is nowhere to be found on the spec sheet. It's not high, to be sure, but certainly it isn't classified information.)

A power switch is provided on the back panel, but the manual recommends that the preamp be left on all or most of the time. It would appear that TARA still expects a three- to four-year tube life under these conditions; the tubes are under warranty for a full three years. And take a look at that heavy-duty power cord! A really nice touch is the inclusion of a TARA Quantum AC power cord—a $125 retail value.

Sonic impressions
Much has been said about the sound of tubes vs that of transistors, the strength of silicon vs the velvet of valves. On the basis of its sound with either digital or analog program material, I don't think that anyone would ever mistake the Passage for a solid-state unit. The mids sounded consistently smooth and disarmingly liquid, with a darkish tonality that gave the sound a rich, chocolatey flavor. "Too soft and liquid" was my first and lasting impression. I may be Tube Man, but these "feel-good" mids were too tubey even for me. It was like having carte blanche in a candy store. String tone was so liquid I could have gone for a swim in the soundstage, while the overtone structure was texturally so high in calories that I almost felt like I was gaining weight during the listening sessions.

The "midrangey" effect was further emphasized by a dull, lifeless lower treble. Soprano upper registers lacked adequate sheen, flute overtones lacked sufficient brightness. Brass blasts sounded muted and were unable to cut through orchestral textures. Brushed and struck cymbals never quite sounded right, and transient attacks and decays were slightly softened and blurred. This was quite evident with Anna Maria Stanczyk's Hamburg Steinway on track 10 of Stereophile's first Test CD. The effect was to blunt the percussive feel of the piano and to render the instrument's overall enunciation somewhat indistinct.

There were also problems in the bass, particularly in pitch definition and tonality. Bass transients lacked impact and control, and timpani thuds turned to Jell-O. Tight control was just not to be heard through the Passage. Upright bass, whether Ray Brown or Rob Wasserman, sounded ill-defined enough to force me to jot down those dreaded descriptors, "soggy" and "rubbery."

To its credit, the Passage projected a reasonably spacious soundstage, though of restricted depth and only decent image specificity. Massed voices were reproduced with the sort of broad brushstroke that left little room for the resolution of individual voices. Instrumental outlines were always slightly smeared, making their spatial outlines less easily resolved.

The most significant handicap was the lack of transparency—a Dance of the Seven Veils with none of the veils removed. This was more of a problem with dynamic speakers like the Ensemble Reference than with the Sound-Lab A-1 electrostatics. The sense of hall inherent in many recordings was diminished, making it difficult to hear deeply into the soundstage.

Ambience retrieval suffered even when there wasn't a hall. Jennifer Warnes's rendition of the "Ballad of the Runaway Horse" (Rob Wasserman, Duets, MCA-42131) is drenched in quite a bit of good-sounding artificial reverb. It should be possible to clearly delineate the halo of reverb surrounding her voice. This the Passage failed to do. The breathy effect of the presentation was diminished, dulling Jennifer's upper registers. All of this worked to some advantage, however, on track 2, where Rickie Lee Jones was made to sound less whiny.

It was on such high-powered recordings as Walton's Belshazzar's Feast (EMI SAN-324) that the Passage really failed to deliver the musical goodies. It was incapable of convincingly reproducing the dynamic bloom of an orchestra, especially when going from loud to very loud. Loud orchestral passages simply sounded compressed and uninvolving. But it was more than just poor dynamics that made the Passage such a musical bore. It all added up: dull, slow highs, opaque soundstaging, smeared spatial outlines, and loss of dynamic contrast. The combination of all of these made tedium of much of my favorite music. Beethoven's Ninth and Bruch's Kol Nidrei failed to move me. I heard the music all right, but it just failed to communicate. The dramatic fire and bite—the music's soul—was absent. There was no possibility of goosebumps: even a JGH on steroids wouldn't have reacted.

I remember the first time I heard Bruch's Kol Nidrei (Julius Berger, ebs 6060). I was engulfed by the acoustic of the hall, in the middle of it all the cello singing so sweetly, so urgently. That memory flooded back as I listened to the same piece through the Passage. I wondered where all the magic had gone.

I compared the Passage's performance with that of the Music Reference RM-5 Mk.II ($1150 retail). Though I'm less enamored of the RM-5's sound than I was when I reviewed it two years ago, the RM-5 still managed to outshine the TARA. The Passage sounded smoother and more liquid through the mids, but the RM-5 did better at the frequency extremes. The lower octaves through the Music Reference were better defined, treble transients quicker and more precisely controlled. The dynamic range from loud to very loud, though leaving me wishing for more, was a step ahead of that afforded by the Passage. Finally, the RM-5's less colored midrange tonality was more sunny than that of the darkish Passage.

The problem with either of these units, really, is the performance level afforded by the Sonic Frontiers SFL-1 that I reviewed in August. For only a fistful of dollars more ($1395 US retail), this Canadian line-level preamp, a hybrid designed by Joe Curcio, blows away the competition at this price. The SFL-1 offers a significant slice of the best sound money can buy. Its ability to flesh out the dynamic bloom of individual instruments, and its dynamic headroom from soft to very loud, put the two other preamps to shame.

In terms of parts and construction quality, the Passage represents a fair deal for $995. Unfortunately, it combines the best and worst sonic attributes of valve amplification. The good news is of a midrange that is a fountain of liquidity: an edgeless, nonanalytic, flowing presentation that's easy on the ears. Then there's the bad news: harmonic textures on the dark side of reality and a dull, soft lower treble.

One of the most challenging and rewarding artistic processes in audio revolves around the mixing and matching of components to produce a synergistic musical blend. If the overly liquid mids and timid upper registers were the Passage's only shortcomings, I would venture to say that such a personality could be put to good use in mitigating the brashness of many budget solid-state amps and loudspeakers.

But what's a poor mother to do with bass control and impact that flunk even kindergarten? One possibility would be to mate the Passage with a loudspeaker that had little bass to begin with. That way, its shortcomings in the lower octaves would be reasonably well hidden. And the soggy upper bass and lower-midrange fullness might even give the illusion of more bass response.

However, there's no hiding or ameliorating the Passage's failure to illuminate the soundstage. Depth was not fully developed, and image outlines were fuzzy and out of focus. The portrayal of individual instruments was broad-brush at best, hindering the resolution of spatial detail. The most frustrating thing of all was the presence of a "curtain" that veiled the soundstage and thus reduced the immediacy of the illusion. Both spatial and low-level detail were obscured to the point that the Passage can be fairly described as a low-resolution device.

Because its retrieval of dynamic shadings was pretty limited, the Passage failed to re-create the dramatic conviction of which live music is capable. Its dispassionate attitude hurt orchestral music the most; I was routinely bored. Dull, slow, colored, and dynamically constrained, this preamp booked me passage all right; not to musical heaven, but to the Land of Nod. Goodnight, and pleasant dreams.

TARA Labs' Matthew Bond informed me late in the proceedings that he has switched from National (distributed by Richardson Electronics) to Golden Dragon 12AU7As. Current production of the Passage uses only the Chinese tubes, which Matthew felt were responsible for a considerable sonic improvement. He sent me a pair of Golden Dragons to try.

At the same time, I finally received a copy of the schematic for the Passage. As I'd already suspected, this preamp inverts polarity. A single 12AU7A is used per channel: one section provides a gain stage, the other is used as a cathode follower. With only a single gain stage per channel, polarity inversion is inevitable. While this can easily be accounted for by reversing the speaker leads at the amp or speaker terminals, the Owner's Manual is curiously silent on this subject—as if TARA is ashamed to own up to the facts. This important information should be explained to the end user. Having already experimented with polarity reversals, I had basically settled on the polarity that sounded best with a given musical selection.

I fully agree with Matthew that the Golden Dragons constitute a significant sonic improvement. Much of the darkish harmonic, or "chocolate-flavored," textural quality that had previously afflicted the mids was now gone. In hindsight, it is clear that the National tubes coated the mids with a euphonic glaze. In contrast, the Golden Dragons sounded cleaner, imposing less of their personality on the sound. I've heard that the 12AU7A is one of the most colored preamp tubes around—probably a reflection of the sad truth that decent-sounding 12AU7As are rare.

The Golden Dragon 12AU7A may be one of the best-sounding tubes of its kind, but even it failed to solve the Passage's remaining problems. That's not surprising; tube substitution obviously cannot effect design or circuit changes. The flavor of the amp changed, but its basic personality remained intact. The ill-defined bass, dull highs, broad-brush image outlines, opaque soundstage, and compressed dynamics were not impacted by the change in tubes. Neither was my basic impression of the Passage.

TARA Labs, Inc.
716 Rossanley Drive
Medford, OR 97501
(541) 488-6465