GOODSOUND!GoodSound! "Equipment" Archives

Published August 1, 2007


Antique Sound Lab AQ1003 DT Integrated Amplifier

I’ve never owned a tube amp -- for me, solid-state gear has always been too convenient, too affordable, and too reliably adequate. Adequate isn’t exactly a ringing endorsement, but when you’re just starting out or don’t know the difference, "good enough" is probably just that. One of the main benefits of a good solid-state amp is its ability to reproduce recordings with accuracy, removed from an identifiable sonic signature. In the solid-state era, "neutrality" has become a high compliment for an audio system. How much more you get with a $1000 solid-state amp than with a $400 solid-state amp is a separate discussion, but the problem with solid-state gear is that it tends to have little personality of its own, particularly in the GoodSound! price range. The Antique Sound Lab AQ1003 DT tube integrated amplifier ($1250 USD), however, has personality to burn. If you’re curious about how much magic tubes can bring to your listening, now might be the time to find out.


Twenty years ago, Antique Sound Laboratory and its affordable tube amps probably couldn’t have existed. Founded in Hong Kong by Joseph Lau, the company is a United Nations of electronics, employing Chinese manufacturing, Russian parts (in the form of EL34 tubes), and North American distribution through Canada’s Divergent Technologies. Prior to the partnership with Divergent, Lau offered tube-based amplifier kits, specifically low-watt single-ended-triode (SET) power amplifiers. However, Lau had limited reach in the marketplace, and his distributors were hesitant to support his plans for more ambitious design and production.

About that time, Tash Goka of Divergent Technologies had received rave reviews for his high-efficiency Reference 3A loudspeaker, specifically for how beautifully it responded to SET amps. Unfortunately, most SET amps were expensive, and Goka was looking for a low-cost alternative that would mate well with the 3A. After he’d talked with Lau and tested his designs, the two agreed to combine Divergent’s expertise in speaker design with Antique Sound Lab’s fine workmanship and ability, to jointly produce affordable electronics that would make musically sophisticated tube systems available to a wider range of buyers. To further its goal of attaining audiophile levels of performance in its products, Antique Sound Lab makes its own transformers, and operates its own metal shop, powder-coating paint facility, and tube-electronics assembly and testing group.


I was surprised at how large the AQ1003 DT is -- and lifting it, I felt every ounce of its 45 pounds. Removed from its double boxes, the polished steel chassis measures a manageable 15"W by 12"D, but its 9" height made for a tight squeeze in my entertainment center. Everything was meticulously bubble-wrapped and Styrofoamed, and each tube -- four large EL34s and four small 12AU7s -- was snug in its box, packed securely under the amp’s protective tube cage. One thing that steers potential buyers away from tube amps is the initial setup. But once the cage was unscrewed, the boxes opened, and the tubes exposed, assembly of the AQ1003 DT was simple, each tube fitting easily into its socket.

On the exquisite brushed-aluminum face, to the left of the Antique Sound Lab logo, are a remote-control sensor and a Power lever with a blue indicator light. On the right are two sturdy aluminum knobs: one for volume, and the other to select among three input sources (CD, SACD, DVD). The firmness and solidity of the knobs, and the nifty remote control of carved wood (which handles volume, source, and mute, but not power), were the first indicators of the AQ1003 DT’s outstanding build quality; another was the point-to-point wiring inside. And the workmanship was just as impressive around back, with three pairs of gold-plated RCA jacks, a set of subwoofer outputs (a nice contemporary touch), six five-way speaker binding posts (to accommodate speakers with impedances of 4 and 8 ohms), and the socket for the detachable power cord.

The wooden remote control, subwoofer output, and tube cage all come standard on the current version of the AQ1003 DT, but the single most ingenious upgrade is the built-in bias meter set into the center of the chassis platform. Unlike transistors, tubes can perform inconsistently or behave a bit temperamentally as they repeatedly heat up and cool down. The meter measures the output performance of each tube set (a dial switches among four positions). You can then recalibrate a tube set by turning one of four small screws. My tubes were pretty evenly balanced the moment they were inserted, but I had to bias them once during the first few hours of listening. Such a simple, intuitive method of evaluation and calibration not only worked superbly, it removed one layer of anxiety associated with owning tubes.

The AQ1003 DT replaced the NAD 325BEE integrated in my system, which also included an Oppo DV-970HD universal player, Monster Cable interconnects, and a pair of Axiom M22 speakers connected to the AQ1003 DT with 9’ runs of Element Cable’s Double Run cable, terminated with banana plugs.


The Axiom M22s proved a beautiful match, their overall neutrality kissed with a hint of warmth from the Antique Sound AQ1003 DT. The combination thrived on music that nods to the organic sound of tube-based studio equipment, even if that equipment is digitally simulated, as on Amp Fiddler’s Waltz of a Ghetto Fly [CD, Genuine 64715]. On "I Believe in You," the bubbling bass, dipping keyboards, and thud of the kick drum maintained a harmonic balance and structure that was completely free from the excessive brightness common with CDs. The AQ1003 DT offered outstanding midrange performance enhanced by clearly audible details. Fiddler’s whispery vocals on "Eye to Eye" and "Possibilities" were precise, and the female singers backing him up on "Unconditional Eyes" sounded soft and sweet in just the right measures.

Prince’s Musicology [CD, Columbia 5171659] is characterized by sharp separation of the instruments and a spacious three-dimensional soundstage. Through the AQ1003 DT, the title track’s bass line began with a crisp snap that decayed into a soft, deep ring, while the horns jabbed the foreground with their brassy framework. "A Million Days" and "Cinnamon Girl" were dense and complex, but the AQ1003 DT was consistent in its ability to translate the musical information contained in these tracks into sonorous beauty. It dealt with "Life of the Party" with ease, effortlessly slamming the beat and tracking the tune’s transient energy, while the slow drag of "Call My Name" had body, and its dynamics were rendered without stress as Prince’s voice swooped from one end of its range to the other.

The temptation to serve the AQ1003 DT a steady diet of acoustically rich, expansively liquid recordings was hard to resist, and I thought I was doing just that when I put Elvis Costello and Allen Toussaint’s The River in Reverse [CD, Verve Forecast 6660] in the Oppo player. I expected the Antique Sound Lab to convey the driving backbeat and electric buzz of the guitar on "Six-Fingered Man," the plaintive frustration in the vocal on "Freedom for the Stallion," the accusation and instrumental sting at the core of "The River in Reverse," and the gentle soulfulness of "Nearer to You." And it did -- the AQ1003 DT deftly handled all of these characteristics. But with this recording, an excess of coloration began to creep into my listening experience, a noticeable muddiness that stopped just short of unpleasantness and reminded me of the large, unsophisticated three-way speakers of my youth that favored heft over agility.

But this woolliness occurred only with The River in Reverse; the recording itself must possess characteristics that the AQ1003 DT’s tubes accentuated instead of optimized. When I listened to "Part I," from William Parker and Hamid Drake’s First Communion [CD, Aum Fidelity 039/40], in which the duo perform in an apartment for a small audience, the AQ1003’s tubes infused their collection of handmade drums with a nuance and an in-the-room tonality that were remarkably arresting and true to life. On "Part III," the pair engage in over 50 minutes of bass/drum interplay, and the AQ1003 DT supported Parker’s resonantly woody and powerfully immediate bass, and the cracking explosiveness and effortlessly controlled attack of Drake’s traps, without ever tripping itself up or succumbing to the kind of congestion that’s possible when an amp comes under this kind of musical barrage.


The NAD 325BEE (and its predecessor, the 320) is a well-known bargain among integrated amplifiers at its entry-level price of $400. In terms of inputs and operability, it offers a wealth of conveniences. Its unabashedly transistor-based 50Wpc boost the bass just enough to let you know they’re there, and extend the treble to just short of brightness. The 325BEE discards none of the intentions of whichever musicians made the recording at hand, and puts the solid in solid-state.

Antique Sound Lab’s AQ1003 DT, if not the NAD 325BEE’s opposite, represented an entirely different approach to the reproduction of music. Its engineering emphasized a lush midrange, which accounted for the exceptional naturalness and old-school warmth that made it wonderful to listen to. I found that its 30Wpc were comparable to the NAD’s 50Wpc, particularly when I remembered that the NAD’s power rating is widely believed to be conservative. At volumes that tested the limits of listenabilty, the AQ1003 DT introduced nothing in the way of audible distortion or breakup. But with the AQ1003 DT you sacrifice input options, a tape loop, a headphone jack, and the low-heat, trouble-free operation of solid-state. You also pay three times as much as you would for the NAD.

The knock on tube sound is that it suffers from a soft, rolled-off top end; mushy, undefined bass; and a loss of detail due to excessive midrange coloration. The AQ1003 DT avoided all of these while offering a more natural timbre and a ripely melodic and rhythmic drive. Those parts added up to a lovely whole.


Among Antique Sound Lab’s line of pre-, power, and integrated amplifiers, the 30Wpc AQ1003 DT is a step up from smaller, lower-powered, entry-level integrateds, while pleading guilty to the qualities that caused tubes to lose out to transistors in the first place: It’s big, it’s heavy, it requires assembly and some maintenance, and it runs hot. In fact, its tubes generate enough heat for you to question whether you’d want to use it during the summer months. In addition, biasing tubes is a nuisance (although with the AQ1003 DT I had to do this only once). And while the tube cage is a nice touch, its bars are too far apart to provide much protection to prying little fingers.

On the positive side, in addition to its warm, graceful sound, the AQ1003 DT’s cosmetics are first-rate, its point-to-point wiring and overall fit’n’finish are miraculous at the price, and its wooden remote control is a minor work of art.

At the end of the day, owning a tubed integrated amplifier isn’t about which amenities you lose or how much it lightens your wallet. It’s about the pleasure you get from your music collection, and the enjoyment that’s added to your listening sessions. Hour after hour, Antique Sound Lab’s AQ1003 DT made music that provided me with relaxation, joy, and simple diversion. The sheer delight you’re likely to get from this tubed integrated should render all else insignificant.

...Jeff Stockton

Price of equipment reviewed

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