LUXMAN SQ-38u

TUBE INTEGRATED AMPLIFIER

$5990

by

MIKE GALUSHA & BRIAN BOEHLER

 

 

FIRST TAKE

by

BRIAN BOEHLER

 

WHO IS LUXMAN?

When you ask the average StereoMojo reader what companies they think of when we talk vintage high fidelity most would answer McIntosh, Marantz, Audio Research, or possibly Dynaco.  To my knowledge, the oldest company is McIntosh which was founded in 1949.  But hold on a minute; how about vintage high fidelity companies outside of America?  How about a company from Japan established 25 years before McIntosh?  Although we tend to think of vintage high fidelity as being American based, we have some examples from around the world that started earlier than our history.

To quote from the Luxman site   “Lux Corporation was established in 1925 when radio broadcasting started in Japan. The radio department opened in Lux Corporation, Osaka, which handled pictures and frames at that time. As the department displayed radio receivers in the store showcases for the first time in Osaka, almost all the passengers stopped there to listen to the superb sound of the receivers. Luxman's history of seeking higher sound quality started from this moment”.

Luxman has had many gifted and talented designers/engineers over the years.  A number of ex-Luxman engineers became heads of their own companies because of changes in ownership.  Atsushi Miura and Masami Ishiguro founded Airtight when Luxman first sold to Alpine. Taku Hyodo launched the Leben Hifi brand which even today shows cosmetic influences of vintage Luxman design cues. Tim de Paravicini who was involved with a number of earlier Luxman tube and transistors amps founded Esoteric Audio Research in the UK.

Most American hi-fi enthusiasts are a little oblivious to the classic high-end equipment from Europe and Asia, and I’m no exception.  I am both impressed and humbled that this hobby is a worldwide phenomenon and I need to open my aperture to appreciate all that is offered.  A global perspective is really important in this regard. 

Luxman SQ-38u Features  

We have reviewed two other Luxman integrated amps here at Stereomojo and both of them where solid state. Both were found to have excellent, musical sonics, impressive lists of features and impeccable build quality.  The SQ-38u has much in common with the others with one major difference it is a  classic 30 watts-per-channel, EL-34-based tube integrated, not solid state. In addition, while this model has been around for many years, it is now in its 11th upgraded version. Luxman never leaves well enough alone. Check out the 2nd generation SQ-38 below, circa 1964.

 I decided to review the Luxman SQ-38u tube integrated amplifier and see what it offered to the average audiophile.  I found a full featured integrated amplifier with enough bells, whistles, and knobs to keep most audiophiles pleased.  Believe it or not they offer tone controls (you can bypass them for better quality) along with a flexible phono-stage which will work with virtually all cartridges.  The unit has a step-up transformer which can be set at high gain, medium gain, or off.  In addition to the tone controls, the unit has a mono switch and some filter settings which help make the most of worn-out or noisy records.  To put it simply; it is an extremely versatile unit harkening back to the 70’s with its feature set.  Some might call it retro while others would praise the fact it actually is useful and flexible.  I believe the easiest way to sum up the SQ-38u is it is a classic tube product but with some improvements like modern parts, voltage regulation, auto bias, and a remote control.  The best elements of vintage and modern design in one versatile package. 

Did I mention that it has a simple remote control that allows volume and mute?  Nothing fancy but easier than having to get up and down to make a simple volume adjustment or to engage the mute if the phone rings or your wife needs to ask a quesiton, and it is a quality metal construction designed precisely for the amp, not a cheapo plastic job chosen from a Chinese catalogue.

A quick laundry list of features and information include the following.  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 SQ-38u is a fixed-bias design which makes use of both local and global feedback.  The unit has chunky output transformers and a large mains transformer encased in black enamel metal covers.

In addition to the four power pentodes, the Luxman has seven small-signal tubes (four ECC83 and three ECC82) and a pair of custom step-up transformers. Gain is stated as 14dB for the line section and 37dB for moving-magnet phono.  I double checked but didn’t see a gain number listed for the moving-coil section.

Talk about useful knobs, how about a balance control, bass and treble tone controls, a mono/stereo switch, a mute button, a low frequency cutoff switch and two speaker connector switches.  They are also easy to locate and nice to the touch. And, there are even two AC outlets on the rear that allow you to plug in your CD player, turntable or other accessories. A "separate" switch on the front panel, allows the SQ-38u to be easily integrated into a home theater system. This separates the preamplifier section from the amplifier. Allowing one to take the output of a Home Theater Processor directly to the amplifier, bypassing the on-board preamplifier completely. Could also be used with a room correction device.

 

 

 

Luxman SQ-38u Fit and Finish  

The fit and finish, and overall appearance of the integrated remind me of earlier pieces of gear.  The quality is very much like the best from the ‘50s and ‘60s.  It has an all wood case as standard, something that most amps don’t even offer as an option anymore and if they do, it cots big bucks. The satin front panel reminds me of the Marantz 7.  It feels heavier than most golden-age tube integrated amps, and seems solid and much better put-together.  The solid build-quality makes many old tube amps feel flimsy and frail in direct comparison.  Overall, I was impressed with the fit and finish and feel it is a cut above most other tube units, or solid-state for that matter. 

As a point of reference, my wife doesn’t particularly like the look of the amplifier.  The wood case and brushed satin faceplate with multiple knobs and switches just seems cluttered compared to many modern day units.  I personally like the look and think it draws us back to a time when equipment was about functionality and graceful style and not audio bling/jewelry.  I think of it as timeless beauty, functionality, and just good looking.  A good friend shared the concept we are often “imprinted” with a look and style when we first entered this hobby. This statement really resonates with me and I can definitely see the connection.  Since beauty is in the eye of the beholder, you will have to decide for yourself.

 

Fedex Strikes Again 

I do need to share one problem I had with the unit.  It hummed very loudly when I first hooked it up!  I assumed the unit must be defective.  My friend, Mike Galusha, will talk about this in his Second Opinion, but suffice it to say, there was a simple fix.

To be fair, you need to understand distributors take one unit and ship it around to reviewers.  The unit had sent to several audio shows, possibly other reviewers and handled very differently by numerous people.  Instead of being inserted into one system and hooked up, they can get substantially more use and abuse than normal.  This situation has nothing to do with the quality of the product but a fact of constant handling and shipping across the country and/or world.  While the unit had a problem from use and abuse, this in no way reflects on the build quality of the product or company.  I just want to make sure people don’t take my sharing of this minor issue as a slam to the quality of the product. 

 

Build Quality

They say a picture is worth a thousand words.  Very clean layout, great quality parts, and well dressed.  I think you get the idea that this is a top notch product designed and executed by a top notch company. 

 

Sound Quality – Part One

Where to start?  I think it would be fair to say this piece of equipment taught me some lessons about what I hear in music.  I have been a solid state guy most of my life.  I have had two different vintage Scott receivers which were tube and enjoyed them for what they were.  They never took center stage in any of my systems but performed back-up system duties.  Being old and vintage, they were noisy and fairly colored.  They served well, but I never took them seriously and felt they were secondary at best.  Jump to the future and I have a tube integrated amplifier from a famous manufacturer which has modern parts, designed with audiophile sensibilities, and built like a tank versus vintage, cheap sheet metal. 

I guess it would be fair to say I have some pre-conceived ideas about how tubes sound.  These prejudices were probably established many years ago when I owned the Scott tubed receivers.  Essentially, my ideas included rolled off bass (usually very loose and flabby), rolled off top-end, golden or caramel midrange, overly romantic sound, and reasonable soundstage highlighting space versus placement.  These are obviously gross generalizations but represent my mindset when I started this review. 

I hooked the Luxman up to my Vienna Acoustic Mahler speakers and fired them up.  Surprise, I heard essentially what my pre-conceived ideas said I should hear.  Needless to say, I was torn since I wanted to like the unit and value what tubes can accomplish.  I listened casually for a few weeks and just couldn’t get excited.  I decided the Luxman should be paired up with smaller and/or more efficient speakers.  Over here in the States, our larger rooms and more power-hungry speakers can put too much burden on many amplifiers especially tube amplifiers. In Japan, one of the most crowded populations on the planet, room size on the average is much smaller. 

 

Another issue is that my Mahler’s are said to be 90db sensitive with a nominal 6 Ohm load, and that is probably somewhat optimistic. The company states that recommended amplifier power starts at 50 wpc and goes up to 500. In short, the amp was being asked to do more than it was designed to do. We talk a lot about the important of system matching at Stereomojo and publisher James Darby has written often that he believes MOST systems in the homes of audiophiles suffer from one form of mismatching or another. This, as it turns out, is a perfect example of what he’s talking about.

 

Sound Quality – Part 2 - Vivid

At this point, Mike Garner from Tweek Geek invited me over to hear the Vivid speakers and to bring the Luxman to hook-up.  Vivid and Luxman are both distributed by Phillip O’Hanlon of On A Higher Note.  Mike is a dealer for both lines and had a pair of the brand new Vivid GIYA G3 and wanted me to hear how they matched up.  Mike Galusha, a fellow StereoMojo writer joined me and we made the trek to Tweek Geek.  We started by listening to the Vivid’s on the Luxman class A solid state amplifier.  In simple terms, it was outstanding but not what we were there to accomplish.  We then hooked-up the Luxman SQ-38u to the Vivid GIYA G3’s and took a listen. 

Wow, many of my perceptions flew out the window.  While it was still a tube unit, many of the areas of concern were either eliminated or they were reduced in a dramatic way.  Bass was not flabby or uncontrolled.  It still didn’t reach to the lowest regions but what was there was very controlled and sounded like real bass.  Acoustic bass was nicely rendered but electronic bass was just not as tight or fast.  Overall, I was impressed and feel like most people who love acoustic music would be very happy with this sound.  The top end was not as extended as solid state but had a very nice sense of authenticity. 

The sense of space and placement were fantastic.  I finally get what tube-o-files love about the sense of realness.  This experience got me thinking I needed to re-insert the Luxman in my system and concentrate on what it did well versus what it didn’t do compared to my solid-state amplifier.  In other words, I needed to approach the review as the cup was half full instead of seeing the cup as half empty.  While this may seem a minor detail, your mindset going into a review can affect the outcome more than most people realize. 

 

Sound Quality – Part Three

The sound was more dynamic than I had originally thought, clean and extended, involving and non-fatiguing.  Short of ultimate bass control there was little to dislike.  Dynamics and slam were limited, but that was not the fault of the SQ-38u, it was a byproduct of the mismatch. If you concentrate on sound quality and a life-like ethos then we have a real player.

 

Picking apart the individual elements of the sound is not the point with this unit.  The overall impression is one of reality and connected to an overall impression of the real thing.  There is not a specific element I could identify which would be considered best of class.  On the other hand, all elements worked together nicely to form a cohesive whole which was more organic and rich in color and texture. 

In my opinion, what Luxman has done is retain the general sound aesthetic of a vintage tube product but built out frequency response and tightened up overall articulation. Hence the SQ-38u has fully modern extension on both ends and the kind of low noise floor 21st-century listener’s demand.  What's more, the unapologetic focus on vintage sound through deeply rendered colors, richness of sound, and texture enhance the musical beauty.

 

Sound Quality – Further Thoughts

When it comes down to the overall impression of the Luxman, it is this It is a versatile player which can be remarkably good under the right circumstances.  Like most components, the Luxman needs the right associated ancillary or complimentary pieces of gear to bring out its best.   When the room and speaker were reasonable, it had good sound-staging, good rhythm and low levels of noise.  Given a modest sized room, there is enough power to drive less efficient speakers with real world music.

So who is the Luxman SQ-38u for?  Primarily, it’s for the music lover.  Do you still listen to disks which sound like crap because of the recording technique?  Good for you!  You can consider this integrated amp a near ideal piece for someone more interested in musical pleasure than ultra-fi purity. It makes your music collection bigger and takes the edge off of most pop music.  It lets you just enjoy the music and not worry about audiophile nervosa. 

Needless to say, I received an education on what a well-designed tube integrated amplifier can accomplish.  Properly supported with reasonably efficient speakers and a less than cavernous room you get a view of music very real and thrilling to experience.  While the sound does not lend itself to electronic music and plumbing the depths with tons of control, it lends acoustical music and most classical music with a sense of realness most solid-state electronics can’t approach. 

 

 

MIKE GALUSHA

When James asked if I'd like to listen to the Luxman SQ-38 and provide some additional comments I jumped at the opportunity, how could I say no.

 

Picking up the SQ-38 from Brian, I didn't want any information on his opinions of the sound, just to know if there were any problems I should be aware of. The only comment was “it's a hummer”. The result of this was my first experience with the unit was on my test bench. While not the latest and greatest I have a fair amount of test gear and took some initial measurements to get an idea of the hum and see if perhaps there were any tubes with problems. It's worth mentioning that permission was obtained from Philip O'Hanlon before I cracked it open to check the tubes.

 

Testing the tubes showed some were weak but none were bad, swapping in a different set had no  impact on the hum.  About 4mV of hum was observed with the HP analyzer connected to the input, this dropped by 6dB when the mute switch was engaged, indicating some type of grounding issue. Running a heavy lead from the analyzer to the ground post on the amp provided the same effect, confirming a ground loop of some type. Inspecting the input section revealed the circuit ground is capacitor coupled to the chassis ground. While this can work well it can also be the source of problems. I'd love to see the inclusion of a switch to connect the circuit ground to safety earth ground. Based upon these observations, a discarded old interconnect was pressed into service as a ground jumper, the shield was stripped back and attached to the ground post and the other end plugged into an unused input. Bingo, noise problem dramatically reduced.

 

A quick power test was made since the analyzer was connected. This particular amp handily exceeded the rated power, managing right at 40W into 8 ohms before the onset of visible clipping on the oscilloscope. THD was .1% at 1W/8ohms and .8% at 40W. Considering the 30WPC rating, this was 25% more power than advertised.

 

Since the hum had been addressed it was time to listen to some music. Initially I inserted the SQ-38 in place of the Atma-Sphere M60 amps. While it didn't sound bad I must admit disappointment. My normal system layout places the source gear on a side wall and balanced interconnects are run from the preamp. I prefer keeping the amount of gear between the speakers at a minimum. The decision was made to re-arrange things and move the DAC and music server close to the Luxman so the additional preamp and cables were not in the circuit.

 

In my notes that day the first sentence is, “My my, what a difference setup makes.”. Actually, I think it best to include my notes as they capture the moment.

 

In the first listen, I fed the amp from my main preamp, which I know was far from ideal, but it was quick and easy and allowed the subs to work. Now I have moved the music player PC and DAC to the front of the room and connected the DAC directly to the Lux. I have some adapters that I hoped would allow the use of the subs but there was too much hum, might be able to reduce this via fiddling with the isomax (Jensen IsoMax isolator) switches but didn't want to mess with it. Playing the same tracks as last night, Ben Webster - Soulville (Verve Master Edition) and it sounds vastly better than before, somehow the little Lux is able to drag more bass from the Abbey's.

 

Very involving, something it was not last night. Intimate and warm but with excellent dynamics at the same time, no seeming shortage of information. I can easily see this with a good source and a relatively efficient pair of speakers providing some long term enjoyment, especially for those more interested in listening to music that messing about with equipment. Very nice indeed.”

 

Really, there isn't a great deal to add to what I captured at the moment. The following day I packed up the amp and Brian and I paid a visit to Mike Garner, our local Luxman, dealer to give this little amp a listen on the fabulous new Vivid Giya G3 speakers. A few weeks prior we had been fortunate enough to attend an afternoon and evening at Mike's with Philip O'Hanlon introducing the new G3 speakers and the thought of spending more time with those and the Luxman was very appealing.

 

The Giya G3 have a pair of approximately 8” side firing woofers and produce some stunning bass. The only area the SQ-38 struggled with was with controlling those woofers, but it did an admirable job. Nothing like a solid state amp with low output impedance, but pretty darn good for most things. Granted, pairing a $6K tube integrated with a pair of $40K speakers is pretty unlikely, the result was very nice. The sound was more dynamic than I had any expectation of, clean and extended, involving and non fatiguing. Short of ultimate bass control there was little to dislike.

 

 

The Luxman SQ-38u is a great amplifier for someone wanting a system that just plays music, with no prejudice towards any genre, no fuss, no massive pile of equipment. It saves serious bucks on connecting cables alone. Features like balance control, bass and treble, ability to connect two pairs of speakers, a headphone jack, and a very high-quality phono section for turntables set this amp apart. Note the the bass and treble controls are not defeatable, so they are always in the circuit.

With its classic styling and real wood case, its style is another unique factor. Luxman is known for its Lexus like overbuilt quality with exquisite attention to detail. A system that will involve and draw the listener into the music and given the build quality, do so for many years to come. A nice DAC and or turntable, a pair of reasonably efficient speakers and one could retire with this amp with the real possibility of passing it down to ones children.

 

More specifically, with 40 measured wpc, speaker matching is vital. A pair of reasonably efficient speakers, perhaps 90+ dB at 1w/1M with well controlled bass and without the desire to try and fill a really large space at high levels is essential.  Speakers with sensitivity of 95 db and above will fill pretty much any reasonable large room with tons of sound.

Once I arranged my system in a manner reflecting how the SQ-38 would normally be used, I was very happy with the result. If you are looking for a reasonably powered, inviting, non-fatiguing with over the top musicality integrated amplifier, I would add the Luxman to your audition list, it will very likely put a smile on your face, it did on mine. The Luxman SQ-38 as a great amplifier for someone wanting a system which just plays music, no fuss, no massive pile of equipment.  The Luxman will draw the listener into the music and let you forget about audiophile sensibilities.  Good system component matching and you have a great system which serves the essence of the musical experience.  The Luxman experience has truly changed my perception of what tubes offer in real world terms.  I am impressed and, via its incredibly musical tube section, fundamentally changed by this listening experience. Solid state has its place in the world for sure, but it seems tube ampification, at least in this amp, renders music that solid state has yet to achieve.

 

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