Following the L-100 Centennial Class A integrated amplifier, the D-100 Centennial CD player and the P-100 Centennial headphone amplifier, LUXMAN continues to celebrate its 100th anniversary with the B-100 CENTENNIAL mono power amplifier.
The new flagship of the Japanese brand’s amplifiers, it is the first monoblock model of its kind since the B-1000f, launched in 2005 to mark the 80th anniversary. At its heart beats the latest version of the LIFES 1.1 amplification circuit. Derived from the LIFES circuit first introduced in the M-10X in 2021, this latest iteration has been further optimized to reduce distortion even further and improve overall performance.
The B-100 Centennial adopts a new ‘4×4’ output configuration, consisting of four triple-stage Darlington push-pull modules in a quad-parallel arrangement for each channel. This configuration delivers 25 W in pure Class A at 8 Ω and 125 W in Class AB. At 4 Ω, the power doubles to 250 W and quadruples at 2 Ω to 500 W. Capable of reaching up to 1,000 W peak power at 1 Ω, it aims for total linearity and absolute control over the speakers, reinforced by a damping factor exceeding 1,000.
The main reason for the doubling of power output each time the impedance is halved is the power supply, which relies on a massive, custom-built, high-efficiency 1,250 VA EI-type transformer, featuring flat copper windings to reduce losses and improve coupling. This is combined with 16 filter capacitors of 10,000 μF each (totaling 160,000 μF), which provide a considerable energy reserve. The ‘peel-coat’ circuits are gold-plated without varnish and combined with specific inductors and numerous relays.
The exterior design features a solid, high-quality 5 mm-thick chassis with machined ventilation slots. The thick front panel with a slanted chamfer is reminiscent of the recent D-100 and P-100 Centennial models and, of course, the M-10X stereo amplifier, but features a single warm-lit analogue VU meter at its center.
Sold in pairs at a price yet to be announced in Europe, the B-100 Centennial mono amplifier represents the new pinnacle of LUXMAN’s current technology and expertise and paves the way for future generations from the century-old Japanese manufacturer.
While the reputation of headphones designed around electrostatic transducers is based on the finesse of their sound reproduction and the sharpness of the sound image they deliver, this technology remains particularly difficult to implement. Very few manufacturers venture into this field, even among the most expert in the world of headphones. Japanese headphone designer Stax has over 70 years of expertise and mastery of this technology. Today, it presents a unique combination of electrostatic headphones and a dedicated portable headphone amplifier. A first in this field!
The Lambda SR-L500, which has undergone numerous optimizations, is now available in a Mark 2 version. This latest model is all about excellence. It will satisfy even the most demanding audiophiles, exceeding their expectations in terms of the naturalness and realism of the sound it delivers.
A VERY LOW-MASS MOVING ASSEMBLY
Unlike electrodynamic transducers, whose architecture is identical to that of miniature speakers, electrostatic transducers have no coil or magnet. Here, their flat membrane is based on a thin sheet of Mylar covered with a thin metal layer deposited by vacuum evaporation.
Two grids frame it. A high voltage, in the order of 500 to 600 V, is applied to these grids, which has the effect of immersing the flat Mylar membrane in a powerful electric field. By then applying a high alternating voltage, which is the analog signal corresponding to the sound message, the membrane is attracted to one of the grids and repelled by the other, and vice versa, depending on the polarity of the voltage it receives. It thus begins to vibrate in response to the signal and reproduces the sound message.
This type of operation has many advantages. Firstly, as the moving part has no coil or connecting wire and consists of a simple sheet of Mylar, its mass can be extremely low. This specific feature gives electrostatic transducers the ability to reach very high frequencies. For the SR-L500MK2, Stax claims a frequency response of up to 41 kHz.
EVEN DISTRIBUTION OF FORCES
Furthermore, unlike electrodynamic transducers, where the moving coil exerts its force only at the center of the membrane, in an electrostatic transducer this force is distributed evenly across the entire surface. This even distribution of the membrane’s displacement force significantly reduces the distortion rate of this type of transducer by preventing, among other things, the appearance of surface ripples. Similarly, their performance is flawless when reproducing the most complex transients.
ESSENTIAL HIGH VOLTAGE MANAGEMENT
Unfortunately, as is often the case, there is a downside to this advantage. As mentioned above, the operating principle of electrostatic transducers requires the management of high voltages. In addition to the voltage used to create the electric field in which the membrane is immersed, the voltage from the signal applied to it must also be high. Several hundred volts are involved here.
However, while current electronics, based on semiconductors, excel at managing low impedances, and therefore modest voltages, high voltage management is far from being their forte. Electrostatic headphones must therefore be driven by specific amplifiers, whose output stages are often equipped with tubes. These components are only capable of handling high voltages. This is a problem for electrodynamic devices with low impedance, which require the use of an output transformer, but in this case it becomes an advantage.
A SUBTLY DESIGNED HEADBAND
However, while having transducers with exceptional performance is essential, they must also be combined with a high-quality chassis in order to perform to their full potential. To meet this requirement, Stax has given the SR-L500MK2 an aluminum chassis specifically designed to eliminate unwanted vibrations that could affect the purity of the sound reproduction.
In the same vein, its headband has a curvature that ensures the ear pads fit perfectly over the wearer’s ears. This ensures a good seal between the listener’s skull and the transducers, guaranteeing excellent reproduction of the deepest bass frequencies. Finally, to preserve the subtlety of the sound, Stax has equipped the SR-L500MK2 with a high-quality cable with very low capacitance.
It uses six very high-purity copper conductors. Titanium is added to the conductors to further optimize their signal transmission characteristics. The end of the cable features a five-pin connector, standard on this type of headphone, allowing the SR-L500MK2 to be connected to the various electrostatic headphone amplifiers offered by Stax.
SRMD10 II portable amplifier for electrostatic headphones
Whether it’s smartphones or portable music players capable of playing the best Hi-Res audio files, portable players are designed to be used with electrodynamic headphones. The reason for this choice is simple. The few volts delivered by the internal battery of this type of equipment are sufficient to drive them.
However, many purists would like to pair them with higher-quality headphones, particularly electrostatic ones, in order to fully appreciate the subtle sound reproduction they are capable of offering. But this poses a major problem. Unlike dynamic headphones, which require only low voltages, electrostatic headphones need voltages of several hundred volts to operate. These voltages are obviously not available on portable devices.
Stax opens up portability to electrostatic headphones
The Japanese designer therefore decided to design a portable amplifier specifically designed to meet their requirements. This elegant box is inserted between the portable music player and the headphones. As with all conventional portable equipment, it is powered by a small internal battery.
The high voltages required to drive electrostatic headphones are generated by a high-frequency DC voltage converter and then filtered to provide stable DC voltages. The headphone bias voltage is 580 V, which is fairly common for this type of equipment. Similarly, the output stages of the SRMD10 II, as this portable amplifier is called, have a very high voltage excursion. It reaches 200 V rms over a frequency range extending from 100 Hz to 10 kHz. This feature allows the headphones to perform to their full potential, even when dealing with the most extreme dynamic swings.
MANAGEMENT OF THE LATEST DIGITAL STREAMS
In addition, to ensure that the SRMD10 II can make the most of the best Hi-Res audio files, Stax has equipped it with the latest generation of digital-to-analog converters. It should be noted that although it is possible to connect the SRMD10 II directly in analog using its 3.5 mm line input jack, it is preferable to feed it digital streams directly from Hi-Res audio files.
Digital-to-analog conversion is then performed by its internal DAC based on an AKM AK4493 chip. It supports native DSD from the SRMD10 II’s USB input. Similarly, PCM playback capability is extended to 384 kHz/32-bit, meeting the requirements of the latest Hi-Res audio streams. It should be noted that Stax has also attached great importance to the selection of passive electronic components used, such as resistors and capacitors. These are sourced from the highest quality ranges of the Korean manufacturer Samsung.
READY FOR THE FUTURE
Finally, the SRM-D10 II is encased in a sturdy aluminum alloy shell. This not only gives it an elegant and modern look, but also ensures durability and high corrosion resistance. This design choice reflects Stax’s desire to combine aesthetics and longevity, making this amplifier not only a device with technical capabilities that guarantee it a certain lead over evolving formats, but also a durable piece of equipment that is ready to face the future with confidence.
THE SETUP OF THE STAX SR-L500 MK2 ET SRM-D10 II
It couldn’t be easier! Connect a device (iPhone, iPad, music player, or computer) to the SRM-D10 II for network and/or file access using a USB cable, and you’re ready to go. The SRM-D10 II is easy and pleasant to use. It powers a single pair of Stax headphones via a proprietary five-pin “pro” connector.
Inside, its AKM 4493 DAC takes care of your data. Finally, this preamplifier can be used either plugged into the mains or on the go. It was in this second configuration that it gave us the best sound results.
THE SOUND OF THE STAX SR-L500 MK2 ET SRM-D10 II
As soon as you place it on your head, you completely forget about the flexible leather headband, and comfort, such a fundamental aspect of headphones, can be enjoyed over the long term, without any excessive pressure. Even without a single note being played, the Stax magic is already at work. This set also offers spatial qualities that are more typical of speaker reproduction.
This explains why audiophiles appreciate the Japanese manufacturer’s creations so much. They find much of what they enjoy when listening to their speakers. It’s true that Stax is unique in the world of headphones because it allows you to enjoy a completely coherent and vast soundstage without disturbing those around you. Let’s not forget that the brand refers to its products as earspeakers rather than earphones.
The three-dimensional image unfolds very naturally on a frontal plane. Rarely will a conventional stereo headphone manage to create such a feeling of openness. You benefit from all the sharpness that their thin membranes are capable of, but also from this fluid atmosphere that unfolds very widely with great ease. Added to this are the remarkable qualities of resolution and precision across the entire frequency range.
This is particularly striking in the low and extreme low registers, where you can hear signals that traditionally tend to be lost. This is evident in the sound of an acoustic double bass. This extension and power at the low end of the spectrum is another hallmark of the Japanese manufacturer, which has always provided us with ultra-wide bandwidth.
And since this “Stax magic” can now be enjoyed on the go thanks to the brand’s specially developed preamp, there are virtually no limits to its use. In all honesty, we didn’t feel any obvious frustration compared to the so-called residential box. And you’ll need to upgrade to the higher-end model to really notice the jump in quality.
OUR CONCLUSION
Stax continues to build its legend by offering relevant products in all price ranges. The Japanese brand now offers a comprehensive range of products that covers all needs at prices that are certainly high, but which allow most music lovers to find what they are looking for within their means. We really appreciated this combination of traditional electrostatic headphones and a portable power supply with a high-quality DAC. This will allow traveling music lovers to always have the best music with them. A great success that we warmly applaud.
Author(s): Estève Fabry
Technical Sheet: Stax SR-L500 mk2 and SRM-D10 II
Origin : Japan
SR-L500 mk2
Price: €925
Weight: 350 g
Frequency response: 7 – 41,000 Hz
Electrostatic capacitance: 110 pF
Impedance: 145 kΩ
Sound pressure sensitivity: 101 dB
Polarization voltage: 580 V DC
SRM-D10 II
Price: €1,095
Dimensions: 75 x 32 x 141 mm
Weight: 450 g
Nominal input level: 230 mV (100 V output)
Maximum input level: 10 V (minimum volume in Line In)
The executives from the Norwegian company, who were visiting Paris (with their axe), had warned us: they had a new model even more powerful than the Verdande in warehouse for the 2026 Chicago audio show.
However, by reverting to a 12-inch mid-bass driver (like the Icon, compared to the 15-inch driver on the Verdande), the founders of Ø Audio started from scratch with this new model. Of course, the Ymir retains the structure of a large driver for all frequencies below the treble, which is handled by a compression tweeter.
But the entire structure has been redesigned, featuring an Audio Q.V.S.T. waveguide that improves control and enables a consistent off-axis response, as well as more stable interaction with the listening space. The newly designed compression driver features a 76 mm carbon diaphragm. Beneath this, the 12-inch driver features a carbon fiber composite cone, with a damping core and a new ultra-linear motor system, ensuring very low distortion at all volume levels and across the entire audible frequency range.
Available in a dark or light finish, the Ymir incorporates a new circuit of three rear side ports. The 10 mm stainless steel front baffle also improves structural rigidity, resulting in a substantial weight of 120 kg per speaker. A new crossover maintains a sensitivity of 93.5 dB, with a nominal impedance of 8 ohms. We are still awaiting the price, which we already know will be higher than that of the Verdande, at 34 990 € per pair.
Primarily designed to be paired with Goldmund active loudspeakers, the new Ouranos Signature and Ouranos Excellence are processors engineered to output only the digital signal.
Both simplified and modernized, the Ouranos models incorporate the latest advancements in the Swiss manufacturer’s proprietary Proteus HT technology. All multi-channel configurations are generated by this proprietary algorithm and loaded into the processor’s DSP. When paired with Goldmund active speakers, Leonardo time correction technology is directly integrated into the DSP of each speaker, as you can read in our Asteria review (test VU#59 FR).
Meticulously crafted, from the quality of the PCBs and carefully selected components to the chassis made from an exclusive aluminium alloy and treated with micro-sandblasting to achieve their refined matt finish, the Ouranos feature a 96 kHz / 24-bit DSP equipped with high-capacity DDR RAM. The new decoding module supports more stereo audio formats and automatically converts Dolby Atmos and DTS files.
The main difference between the two models is that the Ouranos Signature has a single port for each digital input, except for the dual HDMI eARC, and one HDMI eARC output, as well as four coaxial RCA ports, each capable of delivering the signal to a single speaker, a pair of speakers or a subwoofer. It is priced at 32 400 €.
More than twice as well-equipped, the Ouranos Excellence features four HDMI inputs, four coaxial ports, as well as three pairs of analogue RCA line inputs, allowing for the integration of sources such as a CD player or a phono preamp. The outputs are still exclusively digital and via coaxial ports, but there are now 8 of them (plus the HDMI). The price reflects the superior quality of the unit, at 78 000 € including VAT.
Billed as a worthy successor to the Pandora, the Helios sits between the Essence preamplifier and the flagship Commander.
Designed to complement the recent Antileon Revelation, though naturally compatible with all power amplifiers on the market, this new Danish preamplifier must be paired with the new dual-mono PSU 5 power supply, also unveiled at the same time.
Designed by Tom Møller, the Helios’s pure Class A topology utilizes brand-new ultra-low-noise dual JFETs. Fully balanced, the circuits draw power from two 65 VA toroidal transformers coupled with large polypropylene capacitors, offering a total capacity of 83,000 µF per channel, with the output signal benefiting from a complete absence of global negative feedback.
Housed in an imposing CNC-machined extruded aluminium chassis, the pre-amp measures 17.3 cm in height and weighs 13.9 kg, whilst the PSU 5 retains the same dimensions but weighs a heavier 18.2 kg. On the front panel of the audio unit, a 4.3-inch (11 cm) TFT touchscreen, positioned behind a 4 mm-thick glass panel, allows you to view and select sources and volume, the latter controlled by a new 85-step relay attenuator.
At the rear, the dual-mono design is evident as all the terminal blocks are completely separated between left and right. In addition to small 12V inputs/outputs and two ports for Green Bias, gold-plated Neutrik XLR balanced ports predominate, with two pairs of outputs and three pairs of inputs. RCA terminals have not been overlooked either, with two pairs of inputs and one output; inputs 3 (XLR) and 4 (RCA) can be configured for fixed volume.
And to make the Helios the core of your system, two extension slots allow you to add the DAC3 module with USB, S/PDIF, AES/EBU and TOSLINK inputs, as well as the PS3 MM/MC phono module, featuring 8 switches to adjust the load. However, this module is based on a single pair of XLR phono inputs, which should be taken into account when choosing your cable or turntable.
We will provide the prices as soon as they are confirmed by the distributor.
