Luxman SQ-38u integrated amplifier
Let's not beat around the bush: this is what an amplifier is supposed to look like. The silver front panel contains over a dozen knobs and switches, yet somehow avoids seeming cluttered. The solid wood cabinet wouldn't look out of place next to Hugh Hefner's cognac decanter. And the controls! The SQ-38u is as full-function as they come ("as they used to come" would be closer to the truth), with a Balance knob, separate Bass and Treble Tone Controls, a low-frequency cutoff (aka "rumble") switch labeled Low Cut, a Mono/Stereo switch, and a mute button; plus switching and connectors for two pairs of loudspeakers. Everything but curb feelers.
The Luxman uses two EL34 tubes per channel in a class-A/B Ultralinear circuit, for a total of 25Wpc into 8 or 4 ohms, or 30Wpc into 6 ohms. (The amp has no apparent means of switching between different output-transformer secondaries or combinations thereofbut it does have those two sets of speaker connectors, plus a control knob for selecting either or both pairs, combinations of which may account for different load impedances and power specs.) The fixed-bias design, with a rail of about 420V (at power), makes use of both local and global feedback.
In addition to the four power pentodes, the Luxman SQ-38u contains seven small-signal tubesfour ECC83 and three ECC82plus a pair of custom step-up transformers. Gain specs are 14dB for the line section and 37dB for moving-magnet phono. (A spec for moving-coil phono gain was not provided.)
The Luxman's component parts are distributed across a number of sturdy PCBs, the largest of which contains the preamp and phono-preamp circuitry, along with those seven dual-triodessome protected with spring-loaded cansand the step-up transformers for the phono section. Very chunky output transformers and a similarly large mains transformer are encased in metal covers; these, like most of the chassis' interior surfaces and even those tube cans, are finished in textured black enamel. Parts quality is good to excellent for this price range, and build quality is fine. It appeared that my review sample had been around the horn more than once, yet it still worked without a hitch.
Installation and setup
In my main reference system, the Luxman SQ-38u took the place of both my Shindo Massetoitself a full-function preamp with an MM phono sectionand my pair of Shindo Corton-Charlemagne mono amplifiers. The Luxman's own MC step-up transformers, with switchable gain for low- and high-output MC cartridges, performed acceptably welland without detectable noise or grainyet for consistency's sake I tended to precede the Luxman's MM phono section with my own step-up transformers: an Auditorium 23 SPU Standard for my low-output Ortofon SPU cartridge, and a Silvercore One-to-Ten for my higher-output EMT pickup heads. My primary line-level sources were a Decibel (v.1.0.2)equipped Apple iMac with Wavelength Proton USB D/A converter and, as a CD player, a Sony PlayStation of indeterminate vintage. At the other end of the system were my Audio Note AN-E/SPe HE loudspeakers and, on occasion, my original Quad ESLs. I used only the Luxman's stock AC cord, and avoided tweaks of every sort.
The Luxman is supplied with a small remote handset, with Up and Down volume buttons and a Mute switch. As with most such things, I appreciated the gesture but tended not to use it.
From record to record, the Luxman SQ-38u was a big-sounding and altogether musically agreeable amplifieryet one whose overall tonal signature wasn't egregiously tube-like. Tonally, the Luxman was nicely balanced from its bass through its trebles, with well-defined sonic contrasts. Musical sounds all had weight and forceeven in the trebles, where higher notes had timbral body and, when called for, lots of impact. The amp didn't appear to invert absolute signal phase through either its line or its phono inputs.
When I listened to Jascha Heifetz's recording, with Fritz Reiner and the Chicago Symphony, of Brahms' Violin Concerto (LP, RCA Living Stereo LSC-1903), the soundfield was huge, instruments therein having good physical presence. Yet far from sounding opaque, there was a decent level of openness throughout the imaginary stage: individual instruments were present and clearly defined, the timpani at the rear of the stage scarcely less so than the fiddle up front. Timbrally, Heifetz's violin had the right signature and tactile "bounce"; the strings had just enough "bite" to sound realistic. It was a tubey sound but not a gooey one, and the orchestra sounded big and powerful, with very good momentum and flow.
On R.E.M.'s "How the West Was Won and Where it Got Us," from New Adventures in Hi-Fi (LP, Warner Bros. 9362-46320-1), the SQ-38u was on a par with the Leben CS300, also reviewed in this issue: rhythmic nuance and impact were good, but not up to the megabuck standard. The Luxman's bass depth was also acceptably good, although the Leben edged it out in that regard.
Taking advantage of the Lux's Mono switchof the three integrated amps I reviewed for this issue, it was the only one that had such a featureI decided to try some of my favorite 78s. The SQ-38u delivered decent punch and presence from Louis Armstrong's "You're Driving Me Crazy" (Parlophone R866), but not as much as my Shindo separates. Classical music on 78s fared better, such as the original 1932 discs of Yehudi Menuhin, Georges Enesco (sic), and Pierre Monteux leading an uncredited Paris Symphony Orchestra, in J.S. Bach's Double Concerto (Victor DM 932): perhaps the greatest Bach recording in my collection, and a stunning testament to Monteux's oft-overlooked greatness.
In a general sense, the Luxman's phono performance carried over to its use with line-level sources. A 44.1kHz rip of Mindru Katz playing the Bach-Busoni Organ Chorale and Prelude, BWV 659, had good musical flow, with decent timbral color and a nice, subtle sense of drama. Likewise, Marianne Ronez and Affetti Musicali performing Biber's Mysteriensonaten (Winter & Winter 910 029-2)easily the best-sounding "Red Book" CD I've ever heardwas hypnotically musical and sonically colorful through the Lux (although sonic texture was somewhat lacking): Every instrumenteven the bass and organ continuosounded almost eerily three-dimensional.
The Luxman sounded okay with the Quad ESLs, although the match didn't strike me as ideal. Compared to the Leben CS300, the Luxman allowed the piano's left hand to sound tighter and cleaner in Elgar's Violin Sonata in E Minor, with Midori and Robert McDonald (CD, Sony Classical SK 63331). Still, turning the Luxman's Bass knob a little to the left didn't hurt at all, especially with pop CDs with unrealistically equalized bass content.
To persist in my efforts to avoid bush-beating, I really enjoyed the Luxman SQ-38u. The Leben CS300 integrated, reviewed elsewhere in this issue, delivered a somewhat more tactile, believably textured sound with notably better bass extension, but the Luxman was consistently engagingif not always quite as excitingand its user interface was the best I've encountered in a contemporary amp.
I'd make some droll remark about high-end audio's anti-minimalist craze being right on schedule, but at Luxman Corporationan 86-year-old Japanese company that ushered in the first age of high fidelitydomestic products with tone controls, mono switches, headphone jacks, solid wood cabinets, and tubes have remained in production for decades. The SQ-38u is no mere vintage reissue: At Luxman, it seems that vintage never went away. A good trip, happily recommended.