With the latest energy standards, the legendary Japanese brand Luxman was in danger of no longer seeing its Class A amplifiers pass the test benches. So it went ahead and redesigned the architecture of its Class AB products, to get as close as possible to the sound usually produced by Class A amplifiers. The result is the Lifes 1.0 feedback circuit, new to the new Luxman L507Z amplifier, the false successor to the L507MkII and the brand’s new flagship integrated amplifier, alongside the L509X. On this occasion, we had the exclusive opportunity to test one of the first units to be delivered in Europe.
On the eve of its 100th anniversary, expected in 2025, Luxman is once again carrying out an in-depth review of its technologies to better adapt to the problems of today’s world. And while the brand has been able to create some of the finest amplifiers for almost a century (from the famous tube models to those based on class AB transistors), it is now having to rethink the design of its products, in order to remove from its catalogue class A transistor amplifiers, which are too energy-hungry and whose consumption is no longer acceptable by many standards (including European ones), which are becoming more and more drastic year after year, as the ecological crisis makes itself felt more and more.
We therefore regret the sumptuous L-590AXII, one of today’s best Class A amplifiers, with a warmth that is typical of this technology, for a power of 2 x 30 W under 8 ohms that is already very comfortable with many loudspeakers. We also regret the L507MkII integrated amplifier, a 2 x 110 W class AB amplifier priced at €6,590, from which the Luxman L507Z takes its base, but with almost all the improvements, resulting in a new price almost
3,000 higher, at €9,490.
Closer to the 2 x 120W class AB L-509X (launched at €9,690 and now at €10,690), the Luxman L507Z, like all Luxman amplifiers, uses a high-inertia power supply circuit, consisting of a large-capacity, highly regulated EI power transformer, combined with eight times 10,000μF filter capacitors, twice as many as the L507MkII and as many as the L509X. The high level of instantaneous current supplied provides great stability, which is reflected in the final sound. The preamplifier section, and in particular the volume control, incorporates the latest developments in patented LECUA1000 (Luxman Electronically Controlled Ultimate Attenuator) technology, derived directly from the C-900u stand-alone preamplifier and already installed on the L509X. This computerised attenuator, whose 3D-printed board is integrated into the amplification circuit, allows volume to be adjusted in 88 steps,
This not only improves the finesse of signal processing as the volume is lowered, but is also more resistant to vibration, making it more robust than previous versions.
New LIFES 1.0 feedback circuit
In addition to this new design, which has been revised to direct the signal via the shortest possible route, with non-angular layout of the printed circuit boards to optimise current flow and limit loops and ground impedance effects, the L507Z’s special feature is above all its amplified feedback circuit. Once again completely redesigned, despite the latest generation ONDF 4.0 (Only Distortion Negative Feedback) further reworked in 2018 for the L509X, this circuit is now called LIFES 1.0 (Luxman Integrated Feedback Engine System). Recently launched on the M-10X power amplifier, its design is based on that tried and tested for more than twenty years up to the last generation, based on three stages, a parallel stage and a stage equipped with Darlington (a combination of two bipolar transistors which enables the gain to be increased tenfold), then a three-stage Darlington circuit combined with a four-parallel push-pull structure for the output stage. Based on this principle, the structure has been further revised to reduce the number of elements connected in parallel and halve the distortion of the amplification stage, while redesigning the output stage on a three-stage Darlington push-pull configuration with triple parallelism, the latter level ultimately closer to that of the L590AXII in pure class A than the more recent L509X in class AB. The loudspeaker relays have also been reworked, configured in parallel and with low resistance. They improve the damping factor, which is also helped by the OFC cabling, which has been shortened and is now even more direct to the speaker terminals.
Change with continuity
Compared with previous chassis, the L507Z chassis is even more robust thanks to its internal architecture, and allows you to play the game of seven errors with regard to its external design, but with one glaring difference: there are no longer six small front-panel selectors as on all other current models, but only four. Speaker management, which lets you choose an A, B, none or both pairs at the same time, is retained, as are bass, treble and balance management. On the other hand, Rec Out has disappeared, while MM or MC cells can now be selected with a single button, if you wish to use the amplifier’s standard phono preamp.
In addition to the two large left and right selectors, used respectively to manage source inputs and volume as always, the VU meters return to the white backlighting of the L509X, where previously the Class A models were yellow-lit and the Class AB models blue-lit. The light grey aluminium chassis, the only colour available and a Luxman reference, is grafted onto the bonnet with the two long plastic grilles familiar from the L590AXII, rather than the new cut-out metal model from the L509X, whose four cast-iron support feet the L507Z nevertheless uses.
There are also two headphone sockets on the front panel, a standard 6.3 mm one and a brand new 4.4 mm one with independent left and right cabling for improved separation of the two channels.
As for the rear panel, it still offers a plethora of connections, through which up to seven sources can be integrated in addition to two pairs of loudspeakers, including four RCA sources with wider (20 mm) copper-brass alloy terminals for input 1, classic (18 mm) and pure copper terminals for RCA Line-2, 3 & 4. Alongside these are a pair of grounded RCA phono terminals and two balanced XLR inputs. A Pre Out output allows you to take advantage of only the preamplifier part, while a Main In input allows you to integrate only the amplifier part of the device, complemented by 12 V/0.1A Trigger inputs and outputs, if you want to switch on several devices at the same time.
As standard (« De série »), the RA-17A remote control model allows you to select inputs and control volume remotely, in addition to a number of sound parameters and, if the amplifier is connected to a Luxman CD or SACD player, the latter’s basic functions.
The set up
The Luxman L507Z was tested on a system that usually houses a pure Class A Japanese integrated amplifier from a competing brand, and immediately found its place. It was connected to numerous pairs of speakers, compared on its phono preamp to a Vida Prima and a Gold Note PH-10, on the headphone inputs to a Sugden Masterclass HA-4 and, of course, allowed us to integrate sources via both its balanced and unbalanced inputs, with, as always for this type of product, greater musical gain when connected to XLRs. The loudspeaker terminal blocks prefer to use forks, although we also connected banana plugs on several occasions. Finally, moving the amplifier around on several shelves and using it during our Solidsteel cabinet test enabled us to check the resistance of its feet to various supports.
The sound of the Luxman L507Z
Luxman is one of the finest names in hi-fi, with an immediate sonic signature that is even more clearly defined in the L507Z than in previous Class AB models. Thanks to its new feedback circuit design, and the tried and tested LECUA amplification and volume management circuits, this new integrated amplifier boasts a level of sonic purity and finesse that has rarely been achieved. More ductile than an Accuphase integrated, even in class A, the Luxman L507Z manages to recapture the silkiness of the L590AXII, while benefiting from a directness of attack closer to the brand’s class ABs. The warmth of Class A may not be 100%, but it’s much more apparent than on the above models, and the roundness is always present, making for a very pleasant listening experience, free to carry the listener along for several hours without any feeling of fatigue.
On rock tracks, the L507Z develops both power and dynamics, while retaining a real flexibility that is even more audible when listening to natural music such as classical, jazz or blues. For the latter, the quality of the soundstage is always ample, as is the beauty of the timbre, benefiting not only the instruments, but even more so the voices, with that special grain and a very analogue feel, even when using a streamer as a source. The particularly classy white backlighting of the volume meters, between which the volume level is now displayed in red, allows them to evolve at will, to the delight of the eyes and above all the ears, from -80dB to a red zone of 0 to 3dB and more, which we didn’t venture into, out of respect for our neighbours as well as our loudspeakers.
Tested with a mid-range MC cell, the integrated phono preamp outperforms many entry-level and mid-range stand-alone preamps, without reaching the level of openness of our two models costing over a thousand euros, while the headphone outputs are everything but relegated to the background, and can compete with top-of-the-range stand-alone headphone amps, thanks to the fact that their amplification circuits are directly derived from those for loudspeakers.
Our conclusion
With the new Luxman L507Z, the brand shows that its engineers have lost none of their ability to challenge the most tried-and-tested technologies in order to improve their models time and time again. With its new Life 1.0 feedback circuit, the new class AB integrated amplifier achieves the feat of getting as close as possible to the usual class A sounds. In addition to the roundness of the sound, the precision of the details and the absence of noise take the listener into spheres of rare splendour, with the added advantage of relatively low energy consumption and a device that doesn’t heat up much. All this comes at a price, of course, but while the €9,490 you have to pay to enter this world is a hefty sum, it’s well worth it for the musical experience you’ll have afterwards!
Author: Vincent Guillemin
Technical sheet: LUXMAN L507Z
- Origin: Japan
- Price : €9,490
- Dimensions : 440 x 178 x 454 mm
- Weight : 25.4 kg
- Amplification type : Class A/B
- Power rating:
- 2 x 110 W at 8 Ω
- 2 x 220 W into 4 Ω
- Input impedance : 180 mV/79 kΩ (XLR); 180 mV/47 kΩ; 2.5 mV/47 kΩ (Phono MM); 0.3 mV/100 Ω (Phono MC)
- Harmonic distortion (THD+N ): 0.007% (8 Ω, 1 kHz)
- Signal-to-noise ratio (S/N ): >105 dB (XLR, RCA); >91 dB (Phono MM); >75 dB (Phono MC)
- Frequency response: 20 Hz – 100 kHz; +-3 dB
- Analogue inputs: 4 x RCA; 2 x XLR; 1 x RCA Phono
