A back-to-the-future tube amplifier?

The Luxman SQ-38 amplifier debuted in 1963 in Japan, and the latest revision maintains a lot of the original's flavor.

Steve Guttenberg
Ex-movie theater projectionist Steve Guttenberg has also worked as a high-end audio salesman, and as a record producer. Steve currently reviews audio products for CNET and works as a freelance writer for Stereophile.
Steve Guttenberg
3 min read
The Luxman SQ-38u: Japanese luxury hi-fi at its best. Tone Audio

Luxman was making high-end amplifiers long before the term "high-end" was coined. Take the original Luxman SQ-38 integrated amplifier; it debuted in 1963, the upgraded SQ-38D came in 1965, and the design was revised and refined again and again over the years. I recently reviewed the SQ-38u, which is the 11th incarnation of the amp! The new one still looks like 1970's hi-fi, but its insides reflect modern thinking. Or should I say modern tube amplifier thinking? The complete SQ-38u review appears in the latest issue of Tone Audio magazine.

There's a weird thing happening in modern tube design: some tube amp engineers try to mimic the sound of solid-state electronics, so a lot of contemporary tube gear sounds more or less like solid-state designs to me. The SQ-38u doesn't fall into that category; it sounds like a tube amplifier that's the product of 48 years of refinement.

For those who prefer solid-state sound, Luxman offers a tasty selection of solid-state integrated amps. Different strokes for different folks.

The beauty of the SQ-38u's exquisitely machined front panel is more than skin deep. The silky feel of the controls is perfect, just like the good old days. The metal chassis is sheathed in a handsome real wood case, and the little remote control handles just volume and mute.

Connectivity is all-analog of course: there are five pairs of line-level RCA inputs, including a phono input; a Rec Out/Monitor; Pre-Out/Main-In jacks; and a set of A & B speaker binding posts. The amp's tube runs to four large EL 34 power tubes, four 12AX7 and three 12AU7 small signal tubes planted within the 15.7-by-7.7-inch high by 12.2-inch chassis. The SQ-38u weighs a very solid 44 pounds.

Unlike most integrated amps, the SQ-38u's built-in headphone amp isn't based on a little 50-cent chip amplifier. No, this bad boy uses the same tube output stage that drives your speakers. So you get the same sound quality from your headphones as the speakers. The amp had no trouble driving difficult headphones like the Hifiman HE-6 planar-magnetic headphones. The sound was extremely dynamic and very transparent; it was on par with my $1,050 Woo Audio WA-6SE tube headphone amp.

Since the SQ-38u design dates back to 1963 I shouldn't have been all that surprised to see that it has tone controls. Wow, it's been a long time since I used a high-end product with bass and treble controls, and I have to say the SQ-38u's are nicely done. Subtle gradations of bass and treble can make recordings that sound less than stellar, such as Bruce Springsteen's "Darkness on the Edge of Town" CD, a lot more listenable. I dipped the treble down a little and the bass up a few notches, and that was much better. Once I really got into the music, I realized what I've missed from the Boss' more recent recordings: his band doesn't sound like a band anymore. Here on "Darkness," Springsteen is playing with his band of brothers. The SQ-38u brought out the best in his music without highlighting the recording's harshness.

When I played an audiophile recording with real spatial depth--as opposed to digital reverberation--the SQ-38u unleashed a fully three-dimensional soundstage. The CD "Nama," by Puente Celeste, was done "live" with no overdubs, dynamic range compression, or equalization, so the sound was palpably alive. The recording so perfectly captures the sound of musicians playing in real time; they listen and react to each other, and the sound was a pure thrill. It goes far beyond mere hi-fi; it sounded like real music.

The SQ-38u, like every preceding generation of SQ-38 was designed and made in Japan. That said, Luxman is currently readying a new lower-cost line that will be made in China. The Luxman SQ-38u is imported by On A Higher Note and retails for $6,000 in the U.S.