Luxman L-509Z Integrated Amplifier User Manual

Luxman L-509Z Integrated Amplifier User Manual

INTEGRATED AMPLIFIER

hen I reviewed Luxman’s L-509X flagship inte- grated amplifier,in May 2018,1 that sleek machine shook me to my vitals. I wrote, “Record after record, the L-509X illuminated every important aspect and area of the recording. It lived and breathed in the air around the notes, consistently creating big, solid, spatially natural images that presented me with a) the roundness and complexity of each instru-ment, b) a holistic sense of the musicians’ intent, c) excellent touch and texture and impact,
and d) a unified whole, regardless of musical style or dynamic level.” I concluded, “the Luxman L-509X integrated amplifier takes a different path to musical involvement. The L-509X is one of the most intimate-sounding, dynamic, texturally nuanced, truthful purveyors of music of my experience.”Luxman’s new flagship integrated, the L-509Z, has the same thick aluminum top plate and steel casework as its forebear and weighs a similarly knee-crushing 64lb. The older L-509X cost $9495; its newer, younger sibling rachets that up to $12,495. The front-panelcontrols are nearly identical, including those big, eye-catching dual VU meters; except for a new 4.4mm Pentaconn five-conductor mini headphone jack and a mute button, the Z matches the cosmetics of the X to a T. But as in all things, appearances can be deceiving. Even

SPECIFICATIONS

Description Two-channel inte- grated amplifier with 4-parallel bipolar, push-pull, class-AB out- put stage. Inputs, line: 4 pair single-ended (RCA; Line 1 and Line 2 are “Original high rigid- ity terminals”), 2 pair balanced (XLR); Amplifier in (“Main In,” RCA); Phono, switchable MM, high/low, MC (RCA). Outputs, line: Rec Out, Monitor, Pre Out (all RCA); two pair loudspeaker output terminals with indepen- dent on/off switching. Input sensitivity/input impedance, MM phono 2.5mV/47k ohms;
MC-H phono 0.3mV/100 ohms; MC-L phono 0.1mV/40 ohms, SE line 180mV/47k ohms; Balanced line 180mV/79k ohms; Main in 1.1V/47k ohms. Output power: 120Wpc into 8 ohms (20.8dBW), 220Wpc into 4 ohms (20.4dBW). Frequency response: phono 20Hz–20kHz,
±0.5dB; line 20Hz–100kHz,
±3dB. Tone controls: Bass
±8dB at 100Hz; Middle ±8dB at 760Hz; Treble, ±8dB at 10kHz. THD: <0.007% (8 ohms, 1kHz),<0.03% (8 ohms, 20Hz–20kHz).
Signal/noise ratio (IHF-A): MMphono >87dB; MC-H phono

70dB; MC phono >62dB; line
105dB. Damping factor: 330. Power consumption: 390W (maximum), 150W (no signal), 0.5W (standby). Supplied acces- sories: RA-17A remote control, power cord.
Dimensions 17.3″ (440mm) W × 7.6″ (193mm) H × 18.2″(463mm) D. Weight: 64.6lb (29.4kg).
Serial number of unit reviewed G30800022. Manufactured in Japan. Price $12,495. Approximatenumber of dealers: 70. Warranty: three years. Manufacturer Luxman Corporation, 1-3-1 Shinyokohama,
Kouhoku-ku, Yokohama-shi, Kanagawa 222-0033, Japan.
Tel: (81) (0)45-470-6980.
Web: luxman.co.jp. US distributor:
Luxman North America, 27 Kent St., Unit 122, Ballston Spa, NY 12020. Tel: 518-261-6464.
Web: luxmanamerica.com.com.

LUXMAN L-509Z

preamp section. The L-509Z has a fully discrete LIFES system in the preamp. Z-Series also has a seven-segment LED display, 12Vtrigger and control terminals, and mid-frequencies (EQ ) adjust- ment controls.” The L-509Z also includes Luxman’s “LECUA 1000 computerized attenuator” and “crack-resistant peel coat PCBs,” the website states.Let’s go over that list of changes. “Fully discrete LIFES” is
Luxman’s new feedback system, replacing the legacy ODNF (Only Distortion Negative Feedback). LIFES stands for Luxman Inte-
grated Feedback Engine System; the L-509Z includes version 1.0, aka LIFES1.0; LIFES is now used in both the L-509Z’s preamp and the power amplifier sections. LIFES1.0 aims to reduce the unwant- ed effects of using negative feedback and is said to lower the S/N ratio and distortion. Distortion is lowered “to less than half of the distortion as compared to ODNF4.0, the final derivation as utilized in the previous X-Series, with S/N improved by 3dB,” wrote Pravel.
The L-509X included only bass and treble tone controls, now augmented by that “MIDDLE” dial, which Luxman says is “effec- tive in the vocal and lead instrument frequencies bandwidth.” L/R

MEASUREMENTS

performed a full set of measure- ments on the Luxman L-509Z using my Audio Precision SYS2722 system.1 The amplifier is specified as having a maximum output power of 120Wpc into 8 ohms; I preconditioned the L-509Z before the measurements by following the CEA’s recommendation, running it at one-eighth that power into 8 ohms for 30 minutes.
Following that period, the top panel was warm, at 92.6°F (33.7°C), and the grilles over the internal heatsinks were hotter, at 111.5°F (44.2°C). I performed a complete set of tests using the single-ended line inputs, as they had been used by KM for his auditioning.
Looking first at the L-509Z’s unbal- anced line inputs, the amplifier preserved absolute polarity at all of its outputs. The volume control operated in accurate 1dB steps in Line Straight mode, and with the volume control set to the maximum, “0,” the voltage gain at 1kHz was 43.7dB into 8 ohms from the loudspeaker outputs and from the headphone outputs and 14.67dB from the Preamplifier outputs. These gains were not affected by switching the tone controls, set to do nothing, into the circuit. The single-ended input impedance is specified as 47k ohms. I measured 43.5k ohms at 20Hz, 41.9k ohms at 1kHz, and 34.8k ohms at 20kHz. In Separate mode,
which disconnects the amplifier’s front-end circuitry from the power amplifier section, the latter’s input impedance was 46k ohms at 20Hz and 1kHz, 35.1k ohms at 20kHz.
The Preamplifier output impedance was 680 ohms at all audio frequencies; the headphone output impedance was 80 ohms, again at all audio frequencies. The loudspeaker output impedance, including 6′ of spaced-pair speaker cable, was low in the bass and midrange, at 0.1 ohm, rising to 0.14 ohm at the top of the audioband. Consequently, the modulation of the
L-509Z’s frequency response due to the See com/content/measurements-maps- precision.

Fig.1 Luxman L-509Z, line input, frequency response at 2.83V into: simulated loudspeaker load (gray), 8 ohms (left channel blue, right red), 4 ohms (left cyan, right magenta), 2 ohms (green) (1dB/vertical div.).

Fig.2 Luxman L-509Z, line input, small-signal, 10kHz squarewave into 8 ohms.

Fig.3 Luxman L-509Z, line input, frequency response at 2.83V into 8 ohms with treble, midrange, and bass controls set to their maximum and minimum (left channel blue, right red).

setting for the remote control allows for comfortable and thorough volumecontrol action with minimal degradation in sound quality.”
So what about “crack-resistant peel coat PCBs”? On a typical circuit board, a thin, lacquer-like polymer is used as asolder mask to prevent unwanted solder accumulations between closely spaced components and solder pads; the mask also provides some protection to the con- ducting traces during manufacturing.But the mask, which is permanent, can cause stray capacitance; Luxman says it “can have a smearing effect on audio signals.” In Luxman’s process, the mask is removable—and is removed, remov-ing the mask-induced stray capacitance.
Another interesting thing about thecircuit boards is the curvy, swoopy course of those 0.1mm-thick gold traces “utilized for each channel of the L-509Z power amplifier section and in other internal locations”; those curvy traces create “better sound, improved current flow, with lower inductance as compared to PCB traces having ‘right-angle’ signal path direction changes,” Pravel said. All internal wiring is OFC copper, and the
last leg, from the output stage to the loudspeaker binding posts, is a copper cable with a 3.5mm2 cross-sectional area.
Inside, each channel of the L-509Z’s class-AB output stage uses three-stage Darlington bipolar transistors in quadruple-parallel push-pull configuration to deliver 120Wpc into 8 ohms, 220Wpc into 4 ohms—same power output ratings as the L-509X. A new,

measurements, continued

**** Ohm’s law interaction between this imped- ance and the impedance of our standard simulated loudspeaker2 was minimal (fig.1, gray trace). The amplifier’s response into resistive loads was flat in the audioband, with its output into 8 ohms (blue and red traces) down by 4dB at 200kHz. This graph was taken in Line Straight mode and with the volume control set to its maximum.
Commendably, both the very close channel balance and the overall response were preserved at lower settings of the volume control. The L-509Z accurately reproduced a 10kHz squarewave (fig.2), with no over- shoot or ringing.
The audioband response with the tone controls switched on but set to do nothing was still flat, but the output at 200kHz was 6dB lower than in Line Straight mode. Fig.3 shows the effect of the tone controls set to their maximum and minimum positions. The bass and treble controls boosted or cut their passband outputs by 9dB, the midrange control by 8dB.

Channel separation was moderate, at 70dB across the audioband. The wide- band, unweighted signal/noise ratio, taken in Line Straight mode with the unbalanced input shorted and the volume control set to its maximum, was a good 72.6dB ref. 2.83V, which is equivalent to 1W into 8 ohms, in both channels. This ratio improved to an even better 83.7dB when the measurement bandwidth was

restricted to the audioband and to 86.8dB when A-weighted. Switching on the tone controls set to do nothing decreased the S/N ratios by 12dB. The blue and red traces in fig.4 show the amplifier’s low-frequency noisefloor at 1Wpc into 8 ohms in Line Straight mode with the volume control set to its maximum. The level of random noise is low, but odd-order harmonics of the AC supply frequency are present, which will be due to magnetic interference from the power transformer. Reducing the volume by 20dB and increasing the input signal by
the same amount so that the output power remains at 1W (green and gray traces)

See stereophile.com/content/real-life-measure- ments-page-

Fig.4 Luxman L-509Z, line input, spectrum of 1kHz sinewave, DC–1kHz, at 1Wpc into 8 ohms with volume control set to the maximum (left channel blue, right red), and to –20dB (left green, right gray) (linear frequency scale).

Fig.5 Luxman L-509Z, line input, distortion (%) vs 1kHz continuous output power into 8 ohms.

Fig.6 Luxman L-509Z, line input, distortion (%) vs 1kHz continuous output power into 4 ohms.

LUXMAN L-509Z

bespoke, low-loss 600VA EI-core power transformer, with round copper windings and 40,000μF per channel of filter capacitance, features “newly developed, large capacity filter capacitors of a more recent internal construction, like those used in the M-10X power am- plifier,” Pravel wrote. The L-509Z adds newly developed Toshin and Nippon Chemi-Con capacitors.
The L-509Z includes a higher- specced MM/MC phono section with a “new two-step gain switch to select between high and low MC settings to accommodate a wider range of MC cartridges,” the web- site states. By using the “Pre-Out” or “Main In” connections and afront-panel switch (“Separate”) that decouples the preamp and power amp sections, the listener can runthe L-509Z’s pre and power amp sections as separate, standalone components. Luxman’s “beeline” technology ensures the “short- est practical signal path implementation,” Pravel explained. “Thepreamp section is located near the rear input-panel, so signals don’ttravel the distance to the front panel. From input to output, short- est signal routes are optimized for minimum capacitance.”

Twenty-eight sharply sculpted top-panel venting chambers, with honeycomb-mesh protective
grids, add to the L-509Z’s allure. A chunky, user-friendly aluminum remote add to its functionality.
Just like the L-509X, the ampli- fier is supported by four large insulator feet made from a cast iron/graphite material, which protect the chassis from external vibrations. “The material density [of the feet] increases from the out- side diameter toward the center to counteract and suppress external vibration effects,” Pravel wrote.

The L-509Z features a large numerical “seven-segment” LED display, which made reading volume levels a cinch across my small room. The VU meters are illuminated by white LEDs, making them easier on the eyes. The back panel sports four pairs of single-ended (RCA) line inputs and two pairs of balanced (XLR) inputs; the first

measurements, continued

reduced the level of the 60Hz component by the same 20dB and those of the higher- order spuriae by up to 10dB.
Figs.5 and 6, respectively, plot how the THD+noise percentage varies with output power into 8 ohms and 4 ohms with both channels driven. The downward slope below 30Wpc into 8 ohms and 60Wpc into 4 ohms indicates that the distortion lies below the noise up to these powers, but it remains very low until the actual onset of clipping. At our usual definition of clipping, which is when the THD+N reaches 1%, the L-509Z slightly exceededits specified output powers of 120Wpc into
8 ohms (20.8dBW) and 220Wpc into 4 ohms (20.4dBW). The Luxman clipped at 140Wpc

into 8 ohms (21.46dBW) and 225Wpc into 4 ohms (20.5dBW). I didn’t test the Luxman’s clipping power into 2 ohms, as the ampli- fier isn’t specified as being able to deliver full power into 2 ohms.
Fig.7 shows how the THD+N percentage changed at 12.67V, which is equivalentto 20W into 8 ohms, 40W into 4 ohms, and 80W into 2 ohms. The distortion into 4 ohms (cyan and magenta traces) and
8 ohms (blue and red traces) is very low, rising only a little in the top two octaves, which suggests that the amplifier has a wide open-loop bandwidth. However, into 2 ohms, the distortion in the right channel (gray trace) is higher than that in the left channel (green trace), though it is still low in absolute terms.

The THD+N waveform at 20W into 8 ohms was primarily the second harmonic (fig.8), which will be subjectively innocu- ous up to much higher levels than those observed in the L-509Z (though some crossover distortion is present; see fig.9). Intermodulation distortion was also ex- tremely low, even into 4 ohms (fig.10).
To examine the performance of theL-509Z’s phono input, I connected a wire from one of the Audio Precision’s ground terminals to the grounding lug on the Luxman’s rear panel. This input preserved absolute polarity in all three modes at all three output types. In MM mode, the input impedance measured an appropriate 44k

Fig.7 Luxman L-509Z, line input, THD+N (%) vs fre- quency at 12.67V into: 8 ohms (left channel blue, right red), 4 ohms (left cyan, right magenta), 2 ohms (left green, right gray).

Fig.8 Luxman L-509Z, line input, spectrum of 50Hz sinewave, DC–1kHz, at 20Wpc into 8 ohms (left chan- nel blue, right red, linear frequency scale).

Fig.9 Luxman L-509Z, line input, 1kHz waveform at 30W into 8 ohms, 0.0036% THD+N (top); distortion and noise waveform with fundamental notched out (bottom, not to scale).

two RCA inputs are on “original high rigidity terminals.” This is “a design borrowed from our flagship C-900u/C-10X preamplifiers,” according to Luxman USA head Jeff Sigmund. “These terminals employ a special copper alloy with the conductivity equivalent to copper and the hardness equivalent to brass. They also feature an improved internal structure allowing for better contact with the associated cable, as well as improved oversized termination points where the 509Z’s internal wiring connects to the rear of the termi- nal assembly.” Why use only two? On the inside of the rear panel, they take up too much space.
Two preamp outputs and one power-amp input facilitate system configuration including biamping. A classic Luxman hairline fin- ish adorns the amplifier’s top panel. The supplied remote control replicates the front-panel options, including power on.
To the lovely, CNC-cut top plate, Luxman adds “blaster-finished” aluminum- alloy front and side panels and powder-coated steel bot- tom and rear panels. Aluminum-alloy blaster finish, which is also used on the remote, is the “same process used in camera finishes by the likes of Nikon and Canon,” Pravel wrote.

Unlike many manufacturers that insist you download the owner’s manual, Luxman included a copy, which, as Art Dudley wrote in his April 2020 review of the Luxman CL-1000 preampli- fier, “suggests a manufacturer who gives a shit about the customer and who realizes that anyone who spends this much money on a single audio product might be presumed to have more than a pass- ing interest in how the thing works.”2

Setup

Once secured in my audio rack, it was a joy to slide my left hand over the L-509Z’s silken casework as my right hand removed the rubbery plastic caps that protect the back-panel RCA and XLR jacks. The L-509Z is beautiful to behold and pleasant to operate.
Sigmund suggested 200 hours of break-in for the L-509Z, and he wasn’t kidding. It sounded confused and bloated on initial hookup—I feared something was broken. But after two weeks of constant streaming, it had come into its own.
I experimented with the tone controls and found the efficacy of the “Line Straight option,” which bypasses the tone controls, to be mostly recording or whim dependent—not sure which. Generally, activating Line Straight made music sound cleaner, better focused, well organized, and orderly but perhaps a little rigid. With Line Straight disengaged, music was less tidy and seemed to fill up the room with sound more easily. I mostly stuck with Line Straight for its exacting sonic signature.
Alongside Mono, Mute, Phase Reverse, and Subsonic, the L-509Z offers Loudness, which increased low-end weight to a greater de- gree than any ’80s era integrated I remember. Engaging Loudness was like wrapping the music in a soggy wool sweater; I liked it, but it made me break out in a rash. Increasing bass via the tone con- trols didn’t achieve the same deep-in-a-sauna effect that the Loud- ness feature did. Some of these controls are only on the handset.

Fig.10 Luxman L-509Z, line input, HF intermodulation spectrum, DC–30kHz, 19+20kHz at 40Wpc peak into 4 ohms (left channel blue, right red, linear frequency scale).

Fig.11 Luxman L-509Z, MM phono input, response with RIAA correction (left channel blue, right red) (0.5dB/vertical div.).

Fig.12 Luxman L-509Z, MM phono input, spectrum of 1kHz sinewave, DC–1kHz, for 40mV input with volume control set to –12dB (left channel blue, right red, linear frequency scale).

Listening

What immediately struck my ear, brain, and backside, to a degree beyond other tubed or solid state amplifiers I’ve had in-house, was the size and stability of the L-509Z’s presentation. L-509Z images were large, dense, and spatially profound, presented within a soundstage of considerable scale. The L-509Z recreated record- ings with nearly life-sized portrayals of musicians, vocalists, and the ambient space in which they were captured—all this in my small listening room. The amp’s pure sonorities in the upper mids through the treble captured my ears. This is an amp of brilliant pu- rity and fluid communication. Its squeegee-clean top end allowed cymbals, guitars, pianos, and percussion to resonate and commu- nicate direct to my gut.
Recordings I know well, such as Miles Davis’s Miles in the Sky (LP, Columbia CS 9628), trumpeter Matthew Halsall and the Gondwana Orchestra’s Into Forever (LP, Gondwana Records GONDLP013), the Horace Silver Quintet’s Finger Poppin’ (LP, Blue Note 4008), and drummer Kendrick Scott’s Corridors (LP, Blue Note 4552189) were presented in near-3D on a generous stage with munificent images.
In those respects, the Luxman outperformed other integrated or separate amplifiers I’ve reviewed or had/have in house. Myreference PrimaLuna and Shindo Labs tubed electronics sounded tonally sweeter; the Luxman inhabited my room as if it had won an election and was implementing its own agenda.
Playing Ella Fitzgerald’s Ella Swings Lightly (Verve MGVS 64021) using the Luxman’s own phono stage, I relished the delicacy of her voice and responsiveness of the ensemble. Equally, my 1957 Lexing- ton Ave press of Sonny Rollins’s Blue Note BLP 1542 ( Sonny Rollins Vol.1 ) sounded pungent, powerful, and barking-mad dynamic: I defy any Tone Poet to sound this good. The Miles Davis Quintet’s Workin’ (Prestige PRLP 7166) smacked me with its potency, pres- ence, and transparency to the source, especially Paul Chambers’s tractor-beam acoustic bass.
The L-509Z was beyond quiet, presumably due to Luxman’s noise-suppressing technologies. Beyond its bass-to-midrange neutrality and superpure, upper-tier clarity, the L-509Z had no obvious signature. It was largely music and equipment agnostic. It allowed recordings, whether from streaming or vinyl, to speak. It did, however, provide a clear view of the accompanying equip- ment, most of which does have a sonic identity and personality.
I was impressed with the Luxman phono stage. The tubed Manley Chinook had a larger presentation and a more relaxed and swinging sense of flow, but the Luxman stage had serious clarity and drive.
Up to this point, I had done all my listening with the Volti Audio Razz speakers, which, with their high sensitivity coupled with the Luxman’s power, superbly charged bass-oriented instruments with drive, and music in general with excellent space and depth, providing consistent delight.

I pulled out the DeVore O/babies. They revealed the Luxman’s purity. The DeVore’s explicit tweeter, though, requires careful matching. I pushed them closer to the back wall. The resulting sound was crystal-clear and graphic with a tight, solid low end. Music didn’t bloom as with the best tube amps, but the L-509Z’s presentation left no detail uncovered. The Luxman/DeVore combi- nation was consistently engaging, with superhigh resolution and excellent front-to-back layering.
Seeking synergy closer to that of the Luxman/Volti audio pair- ing, I invited the venerable, tried-and-true Spendor BC-1s to my even more venerable (circa-1860) tenement apartment.
In his October 1978 review of the Spendor BC-1, J. Gordon Holt wrote, “Its assets include truly remarkable reproduction of depth and superb imaging and scale. … Despite their manifest shortcom- ings, these speakers can recreate the gestalt of live music like few

systems—so well, in fact, that we found ourselves digging out old records we hadn’t listened to for years and enjoying them for their content as well as for their naturalness. … Summing up, then, we would characterize the Spendor BC-1 as a music lover’s speaker system rather than an audiophile’s system.”
I wish he could have heard them with the Luxman.
The Luxman didn’t overcome the BC-1’s wooly bass, but as Holt stated, music sounded live and natural; the Luxman driving the Spendors was a natural fit, like Mingus’s bass with Dannie Rich- mond’s drums. The duo made music feel good, effortless, and fun. Records pulled me into a large, deep stage, liquid yet punchy and large in scale. I could’ve listened to this jam all night.
That little speaker with the big voice, the GoldenEar BRX, also sounded alive and liberated when driven by the L-509Z. The amp paired smoothly with the speaker’s expressive folded-ribbon tweeter and 6″ mid/woofer, providing a luminous stage with dead- center focus and an airy, ambient glow. Playing Coleman Hawkins with the Red Garland Trio (LP, Prestige Swingville SVLP 2001), the master tenor player sounded relaxed and airy, guttural and groov- ing, the other trio positioned a step or two behind him on the stage. The Luxman provided a swinging, happy gestalt that moved and liberated this listener.

Conclusion

Some amplifiers make you work to understand their meaning and message. Others shout their personalities like “Swifties” aboutto see their heroine. The Luxman L-509Z never shouts, barks, or begs. Its message is clarity, balance, coherence, seamlessness, quietude, and a certain invisibility—in keeping, I believe, with a Japanese audio aesthetic of delivering music artifact free, above all else.
As Luxman’s evolving noise-suppression technologies make the company’s amplifiers more silent, what is left behind is purity and focus. The L-509Z builds on tradition without losing the plot. It’s an exacting integrated amplifier with a good phono stage, a bevy of control options, and plenty of power. The Japanese company’s flagship integrated merits a “Sai-kōkyū” designation. We call it Class A. ■

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References

• ラックスマン株式会社｜プリメインアンプ、プリアンプ、パワーアンプ、真空管アンプ等、オーディオ機器のご案内 - LUXMAN
• luxmanamerica.com.com
• Home Page | Stereophile.com
• Luxman L-509X integrated amplifier | Stereophile.com
• Home Page | Stereophile.com

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