Luxman M-10x power amplifier

Luxman is looking at the 100th anniversary of its founding in 2025, and has renewed the amplifier circuit topology which has been used in their amplifiers since 1999. With improvements we achieve a more realistic, fresh reproduction - rich in musicality The result is an incredible refined product. Made in Kanagawa, Japan it is close to perfect, especially when it comes to price/performance and the materials used for production:

The appearance may look beautifully minimalistic, yet  beneath its sleek design you’ll find a wealth of workmanship and a raft of smart details.

A new feedback engine 

Feedback is widely used in amplifiers to reduce distortion, but can have negative side effects. In fact a badly designed amplifier can measure well - using lots of feedback - but sound hard and unlistenable.

Luxman already uses minimum feedback in a topology they call ODNF* 

* ODNF is an abbreviation for Only Distortion Negative Feedback.

How to further improve?

Introducing LIFES

By repeatedly auditioning and rigorously scrutinizing and combining the selected parts, we have achieved the highest performance and quality suitable for use in Luxman's next-generation components. In LIFES Version 1.0, by simply reconstructing the entire circuit, we succeeded in reducing the number of parallel elements while improving performance. The distortion during amplification has been reduced to less than half. 

The current amplification stage has a 4x2 output configuration that combines two three-stage Darlington circuits and quadruple paralleled push-pull amplifier circuits that handle various load conditions, and instantaneously develops up to 1,200W+1,200W (1Ω) from a rated output of 150W+150W (8Ω). We have achieved complete power linearity up to 1,200W (1Ω). Along with pure class A operation up to 12W with careful bias current setting, it achieves both overwhelming power and sound quality with a sense of density at a high level.

We say: Amplifier designers are constantly working to achieve absolute purity in amplification. For those that take an interest we thought it may be of value to do a brief explanation that follows:

 

What is Darlington?

Here is what the simplest single-ended regular amplifier circuit looks like: 

Here is a Darlington amplifier: Two transistors are used together.

What are the benefits of Darlington transistor configutation?

• It offers very high current gain in comparison to single transistor.
• It offers very high input impedance.
• It uses few components and hence can be used for easy circuit designs.
• It can amplify signal to larger extent.
• It allows designers to drive more power applications by few mA of current source.
• It is very sensitive to current.

With fewer components the amplifier can effectively reach into the lowest level nuances and reproduce the ambience of a recoding. A higher level of "presence", a "bloom" around instruments is a result. 

Next; improving dynamics through a High inertia power circuit

The power supply features low-loss Kyocera Schottky rectifier diodes, a low-loss EI-type power transformer with flat copper windings, and 80,000µF of filter capacitance. Current is delivered to each channel's output transistors with a thick copper bus bar; another bus bar connects the devices' push-pull output to the speaker binding posts via a high-quality relay. This relay has four switch elements connected in parallel to reduce contact resistance. The power supply rails for the driver stage use high-performance regulator chips and selected Zener diodes, the latter manufactured by Vishay in the United States. The 0.1mm-thick traces on the printed circuit boards are gold-plated.

 

Reviews

 Stereophile's John Atkinson was keen to listen to the new Luxman - he said this about Luxman's Power Amplifiers.

"Listening to some of my hi-rez live piano recordings, I was blown away by the sheer force the massive Luxman endowed the instrument's left-hand register with. The midrange and high frequencies sounded unforced and natural"  

 Luxman wins Stereophile product of the year     

"Apart from the soundstaging capabilities and much-improved transparency, there is something even more important that makes the Luxman combo so outstanding: bass quality is probably the area where the Luxmans made the biggest leap. The bass of the Amplifier is deep enough for any recording and it has enough weight not to cause a proportional misbalance in the frequency spectrum. It digs deep into the basement yet the sound does not stay confined underground and swiftly gets back to daylight if the music calls for it. On top of it, the bass of the Luxman combo is miraculously delineated"

Specifications