Luxman 590X Amplifier

I recently wrote about my visit to Audio Consultants

At that visit Stephen Harper, the owner saw I like the sound of the Luxman amplifiers and suggested we devote another afternoon to hearing two Luxman integrated amplifiers. So, a few weeks later I bowled over to Audio Consultants on the Calleva Park Business Park.

The system was more or less the same as the one I heard on my first visit with the Luxman D-10X CD player (although it is actually a CD/SACD and DAC), the Luxman L-509 X and the Luxman L-590 AX Mk II amplifiers and the Kudos 606 speakers. The larger Kudos 707 were out with a customer. A range of cables were used from Gutwire although Audio Consultants also think highly of the Audioquest range.

I had taken along 4 CD/SACDs which represented a selection of musical tastes and recording quality. They were the Reference Recording of Beethoven’s Ninth Symphony with the Pittsburgh Symphony Orchestra conducted by Manfred Honeck, Peter Gabriel’s Up, Diana Krall’s The Girl in the Other Room and Mike Valentine’s Chasing the Dragon CD Volume I.

To give a good chance to hear the two amplifiers properly, I settled on using the Finale from Beethoven 9th, Sky Blue from Peter Gabriel’s Up and Temptation from Diana Krall.


Luxman L-509X Amplifier

The first amplifier listened to was the Luxman L-509X. Luxman has a wide range of amplifiers with two main ranges of integrated solid-state amplifiers. One range consists of mainly Class A amplifiers and the second Class A/AB amplifiers. Both the Class A and Class A/AB have variants of each. As you go up the ranges there is more power available especially into 4 ohms and the mass increases indicating better power supplies. Needless to say, there are also other changes including price.

The Luxman L-509X is the top model in the Class A/AB range consisting of the L-509X and the L-505UX II. The L-509X employs a push-pull output circuit with an output of 120Wpc into 8 ohms or 220Wpc into 4 ohms.


Also featured in this and other Luxman amplifiers are "peel coat" printed-circuit boards: After the copper signal paths have been traced—with gentle curves and a thorough avoidance of drastic bends—Luxman peels off the board's PVC coating, then gold-plates the traces to eliminate any dielectric effect. Of the amplifier's 29.6 Kg (65lbs) lb weight, 6.4 Kg (14 lb) are accounted for by its 600VA, EI-core-type power transformer, made by Nippon Chemi-Con, "with customizable 10,000µF x8 capacitor blocks." Toshin and Nippon Chemi-Con capacitors, Schottky and ROHM diodes, cast-iron footers to damp out unwanted resonant frequencies and wiring of unplated, oxygen-free copper are other standout elements of the Luxman L-509X.

The L-509X is superbly built and there are no bolts/screws on open display. All the controls work smoothly with just the right amount of resistance/pressure needed to make them work. The amplifier is superbly engineered which may make you leave the remote control on the chair to interact with the amplifier. Everything is well placed and just works.


As this amplifier is made in Japan, you can expect a lot of audio engineering with the usual letter spaghetti. An integral part of the design of the L-509X is LUXMAN's original ODNF* amplification feedback circuit, featuring a high-speed primary slew rate, an ultra-wide bandwidth and a low level of distortion that is achieved by feeding back only the distorted components of the audio signal from the output of the amplification circuit. The L-509X is equipped with the latest Version 4.0 ODNF providing an enhancement of accuracy in distortion detection due to the triple-paralleled first stage error detection circuit. Lower impedance and a higher signal to noise ratio have been achieved due to the paralleled first stage and Darlington equipped second stage amplification circuit. A 3-stage Darlington circuit and a 4-parallel push-pull structure is used for the output stage, similar to the M-700u power amplifier. This achieves output of 120W+120W(8Ω) and 220W+220W(4Ω), enabling the L-509X to drive speakers.

*ODNF stands for “Only Distortion Negative Feedback”.


The amplifier also has the LECUA1000 at the heart of the preamp section and the volume adjustment control of the L-509X. This computerized attenuator is integrated with the amplification circuit, a feature integral to the high-end LUXMAN C-900u control amplifier. LECUA provides an ideal level control system that allows smooth and fine adjustment of the volume over 88 steps, thereby minimising the deterioration of audio quality at any point of the volume adjustment range. An advancement of the New LECUA1000 is the 3D design layout. The attenuator circuit board is directly connected to the amplification circuit board. Signal routing has been minimized and efficiency has been enhanced. In addition, this design is extremely resistant to external vibration and eliminates changes in audio quality over the volume control range. The robust nature of this system ensures longevity and durability.

*LECUA stands for “Luxman Electronically Controlled Ultimate Attenuator”.

Luxman pays extreme attention to every detail and their amplifiers have been heavily refined. How much detail? These amplifier designs are listened to by one person. He wondered whether the tension that the transformers were bolted to the chassis affected the sound quality. He asked for a series of amplifiers to be built with different torques for the transformers. He listened and preferred one particular value and the amplifiers are made using that torque. Ah, you may say but won’t that change as the amplifiers are sent halfway around the world. Good point. The amplifiers are built with locking washers that bind them to the chassis.

A measure of the attention to detail.

More information can be found at:

All that is great and good but what does it sound like?

In a word, superb. We played the Diana Krall track Temptation and the track sounded superbly natural and organic. The individual instruments were well separated in a coherent 3-D soundstage. The track starts with a stand-up bass that despite sounding big and powerful, it was easy to hear the tonal characteristics of every note played, the way each note was being played all without weakening the power of this big bass instrument. Unlike other systems there were no 10-metre pianos, Krall’s piano was naturally sized and it was easy to hear it as a percussion instrument. Very real and in the room. But when the group started to motor the power was heard and felt. There was real weight to instruments without making them sound slow, fat or tubby. But the main plus for me was how easy it was to just relax and enjoy the music. Yes, the music was not my cup of tea but the players, including Diana Krall on piano, Christian McBride on bass and Terri Lyne Carrington on drums know how to play their instruments. No cardboard cut-outs and Diana Krall is there in 3-D space, with all the intonation of her singing easy to hear.

But sometimes easy to hear and natural can mean dull and boring. On to Beethoven Ninth, the Finale. The track starts quietly in the huge environment of the Heinz Hall in Pittsburgh and the Pittsburgh Orchestra sounds very 3D and the instruments real. And then…BANG….real power and dynamics. I am always amazed at how powerful a full orchestra (even a small one) sounds when they all come in together. OK, capturing all that power, seems to be beyond any audio system, but this system did exceptionally well. And as the track develops there is real power coming from the system without any sign of it running out of power. The finale gets big and powerful and then in comes a single male voice and the naturalness of that voice was special. Yes, this is a Reference Recording and I would expect it to sound superb, but this was something else. And later in the track, as the Mendelssohn Choir of Pittsburgh joins in, wow. All still sounding natural. No complaints as far as power is concerned.

OK, something quite different, Peter Gabriel’s Up album and the Blue-Sky track. This is a real mix of many different bass instruments with some natural instruments, some processed natural instruments and synths of every flavour, all well mixed and balanced. There were some really deep bass notes probably from bass pedals. And the bass from Tony Levin, no doubt using the infamous Chapman Stick. This instrument is a really difficult instrument to play and Tony Levin is a master. I remember going to a Steve Wilson concert at Coventry University a few years back and noticing the bass player was also using a Chapman Stick. I commented to my friend and he told me it was Nick Beggs…..not the Nick Beggs from….yes, Kajagoogoo…!!! Funny olde world.

On this track, it is easy for the bass to become a little confused or indistinct as some punishing instruments are being played. But not here, every instrument was separate and powerful. They added the right weight and allowed the track to develop. This track has three main parts and in the final part, the ‘choir’, previously, did not hold my attention…..BUT it is the Blind Boys of Alabama. This time round it was anything but boring as it had real weight of these large fellows with their big, powerful voices. I dared not play I Grieve as that is a really powerful track about death. Too emotional.

Stephen Harper could see that this amplifier was making a positive impact on me so we just played more music for fun and then it was time to change the amplifier to the Class A Luxman L-590AX MK II.


Luxman 590AX Mk II Amplifier

The L-590AX Mk II has similar features to the L-509X, ODNF feedback, the LECUA volume control and minute attention to every detail. This Class A amplifier has an audio output of 30W + 30W (8Ω) and 60W + 60W (4Ω). Its power consumption is 330w with no signal, compared to the L-509X’s 150W. The L-590AX Mk II is clearly pure Class A and I am guessing the L-590X runs in rich Class A before going into Class A/B. I believe it runs up to 30w in Class A.

Starting with the Peter Gabriel track the voices were more weighty, the images more solid and the whole feel of the track slightly more organic. The bass was more solid but still informative. So all good news then? Not quite. We were comparing two amplifiers that produce more power and current than their specifications imply. Despite that, the system was in a very large room and we were playing a powerful track with lots of deep bass, quite loudly (understatement). The amplifier did not run out of power but when all the bass instruments were playing it became more weighty but lost a little bass definition. I suspect that using the amplifier in a more reasonably sized room would not cause problems. Having said that I can easily understand why some are drawn to the Class A sound of the L-590AX Mk II and others to the L-509X.

The Beethoven 9th track finale did not show any such issues. It was more 3D and open and the tonal density was more intense with the Class A L-590AX Mk II, with voices having the edge due to their solidity. This amplifier brought back memories of going to classical concerts and hearing an orchestra playing powerful music in a large venue. I heard the same type of sound when we played the Mike Valentine track.

The Diana Krall track showed the same changes with more weighty bass and solidity of images. Her voice was more natural and easier to listen to without losing any of the emotion in her voice. The integration of the musicians was better and it was easy to get lost in the track and just enjoy the music.

Summarising what I heard with these amplifiers, they are both exceptional amplifiers and the choice between them must be decided with a listening test using your equipment and music taking account of the differences in costs. The L-509X costs £9,300 and the L-590AX MkII £7,800. And that is exactly where Audio Consultants can help. The whole system must be an integrated whole. Stephen said attention has to be paid to the supports, cables and power system as they are essential parts of the whole system.

And then, as with all good shows, he performed a grande finale that improved the whole system by making a straightforward change. It was then time to go.

Stephen could see my disappointment about leaving and then made a great offer, would I like to borrow the Luxman D-10 CD/SACD/DAC and two examples of the ‘change’ items? Before he could reconsider, I had said yes, too late to change your mind.

And I will write my thoughts on those items in a future review.

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