Leben RS28CX preamp


Speaking of a “Leben” product is like wandering in a sort of middle way, on an innovative and very original ground that does not mean compromise, but rather meditated choices and reasonableness.

This is due to the fact that the Japanese through and through brand, does not reach the peaks of esotericism and price as other Japanese products do. I can speak of Audio Note Kondo or Audio Tekne, just to mention two well-known brands of the Land of the Rising Sun, which have turned their creed and personal way of being on the market into a sort of “audiophile Puritanism”. Leben follows an alternative path. Mr Kondo's design creed aims to a target of musical research, instead of looking for an exclusive circuital choice or a particular passive component. A research that is not very standardized in a modern audiophile world where everything seems to perform in a uniform or, at least, alike way.

Leben’s creator, Mr. Hyodo San, started his career at Luxman’s where he used to design tube devices. Besides, he brought about an added value for an audio builder: the fact of being a guitarist and a musician too.

In the sober but nice website, you can find few but significant news concerning the brand production essentially based on three preamplifiers, one only phono, two integrated and, at the moment, one power amp.

Mr. Hyodo did not give in at the very profitable temptation of dividing the production (I could say… as others did, a bit cunningly… yes, I say it) into qualitative “steps”- always more and more expensive - of the same device, maybe changing a handful of quite cheap internal components in order to justify a final and twice increased price. He has simply focussed himself on a small number of machines where the differences rest on the preamp functionality or on the output power of the amplifications, rather than on the musical performances that always respond to the designer’s best intentions.

In brief, no easily improvable or intentionally not improved product comes out from his artisanal lab. There are no MK versions or additional changes of an object. Every product enters the market mature or fully responding to its aims.

The solely concession to “change” are the kind of tubes placed into each device. Being a lover of them, he rightly thinks that the best performances come from the exemplars produced until the end of the ‘80s. Therefore, he prefers to use NOS tubes, when available, instead of new types, with the unavoidable variability of the electric parameters during the years.


The musical box

The outcome of the test on the Leben RS28CX preamplifier requires a close analysis to exhaust all its cues and characteristics. Let us start saying that it is not brand new: the very first C version was made in 1998, although it was a different product and design, moreover with different tubes, while the CX model dates back to 2006.

So why coming back to the subject?

Mainly, for two reasons.

The first one is the high quality of this gear that deserves a further deepening and a sort of consecration, always pointing out all the strengths and weaknesses, since every object that reproduces music, also the dearest and exclusive one, has some faults: at least concerning the “reproduction” issue. The second reason is the praise that has to be recognised to the productive policy of the brand, which makes of the longevity of its products a commercial creed: a benefit for the purchaser.

If you love the novelty at all costs resign yourselves to it and let yourselves “fall” in the net of who appears, surely not phony, but unquestionably commercially astute.

Maybe someone would consider what I am saying as excessive or politically incorrect, but, you know, sometimes it can be useful.

Moreover, this preamp, with the passing of time, performs always better. You can find out new emotions while listening to the records you think to know deep inside. In short, it needs time, your time.


How it is made up

The appearance of a machine is something easy to see and evaluate with our own eyes. This is why I do not like to talk about it, but I will make an exception here.

There is a similarity with some old products due to the gold coloured refinement, which recalls the great age of Luxman, or to the well-refined and polished wooden sides.

It is a charming object consonant to every listening room, whether it is a typical bare room of some sad audiophiles or a common living room.

In this model, the power supply circuit is set into an identical small unit, not very heavy though, that has to be placed alongside the main chassis, a couple of centimetres aside.

There is nothing so gigantic here to strike the imagination of the most unwary customer, no brainwaves or subterfuges just to look like something else: only grace and sense of measure.

Good level for the components and good make for the connectors. As the circuit is nearly air wired, this represents an advantage - for the constancy of the performances in the course of time - if compared with the common Polychlorinated biphenyls printed circuits.

Soldering and junctions are well made and if you look inside you can notice that everything has been made, besides in an artisanal way, in an easy way, too. I do love praising slowness.

The passive components are very good without strange esoteric capacitors realized in the nights of full moon: electrolytic Nichicon and Elna with metallic polypropylene (when low values are required) Riken resistors and an Alps Blu potentiometer.

In the supply block, there is an adequate traditional transformer with a NOS RCA 5Y3WGTA rectifier tube and a solid state equalization, together with an inductive filtering system.

The gain circuit counts a Shunt Regulated Push Pull (SRPP) scheme used for years by several manufacturers (i.e. one out of four or five circuits needed to build a preamp), which is generally defined by an output low impedance and a high gain. The gain here can go up to 25,2 db with a maximum output equal to 80 V: a very high value, sufficient to drive any power amp.

Luckily, Mr. Hyodo, on the rear of the preamp, has put a small potentiometer to make variable the output on the RCA clamps. This because, if used, the fixed output can be excessive with normal sensitivity power amps, like my Pass.

It can be useful though, to calibrate this potentiometer and use, for regular listening levels, the normal volume switch set around 12:00 hours even if, the fixed output, without another potentiometer, can guarantee a higher clearness level.

The line stage tubes are two 6CG7 General Electric’s, tube that at that time was used not only in the audio segment but also for the deflection of the TV sets. It is a strong tube, in brief, a version with the Noval socket of the famous 6SN7. It has been employed by many manufacturers, for example Audio Research and Conrad Johnson, as driving stage for tube power amps.

The phono stage follows what Mr. Hyodo considers a masterpiece: the scheme of the Harman Kardon Citation IV: a CR type equalizer with passive Riaa, hence free of negative feedback, in this case only between the two stages which have been made active by the two General Electric 12AT7 tubes.

The gain is of only 20 db and that reduces the utilization and requires the use of a step-up transformer with a congruous gain matched with MC cartridges with a not very low output, let us say not below 0,3 mv.

In this case, it helps the generosity of the line stage and, by using the fixed output, the low gain of the phono is partially balanced.

I have personally used, with great satisfaction, my Lyra Lidian Beta cartridge whit its quite strong output. Nonetheless, it has been sufficient to pair it with two step-ups with a transformation ratio 1:10 to get a congruous gain.

To minimize noise problems are needed a careful estimate of the mass points and an exemplar manufacture. However, the employed circuits and the intentional lack of a counter reaction do not surely go towards the direction of avoiding the hisses. In addition, Mr. Hyodo has inserted the tubes in a metal container to prevent from microphonic effects.

The preamp is rather versatile with a balance control (very useful indeed) and a double input bar (less useful…). There’s also a warm-up system that gives current to the tubes progressively, as prefigured by Mr Hyodo in all his devices to preserve the tubes health. A pilot on the front shows the full efficiency.

The preamp needs at least thirty minute of warm-up to express itself at best, but after few nanoseconds, it can already tell to the lucky owner what it is capable of.


Listening session

Smart audiophiles, I mean those who develop their system with humility and judiciousness, who improve their sensitivity without turning to the plethora of “self-sanctified pundits”, know very well the importance of the preamplifier.

Some lightweight technocrats will tell you instead that it is not true and that when all has been said and done the preamp is only a gain damper, hence an unnecessary component.

I have never listened to a system whit a source directly connected to the power amp that was performing more than decently, included the almost entire range with a passive preamp.

The preamp is necessary and it has to be of better quality than the other components of the system.
You can buy the most expensive loudspeakers, the most transparent and dynamic source, but if your preamp is just mediocre, the sound will be mediocre too.

Today it is quite difficult to find, at the same price of this Leben preamp, a gear that performs very badly. Better, I would say that most products of this category show a pleasantly “Hi-Fi” sound, well-balanced even if, quite often, a bit standardized.

Maybe it is something related to our times, where the majority desires only objects that are appeasing and homogenous, let us say standardized and not very demanding: neither an effort in searching the best conditions of use, nor a different listening or something that can catch us “unprepared”. The aim of Taku Hyodo san is reaching a natural sound with connotations of firm personal character. A sound maybe not so catchy (and then tiring) but a sound that generates in the user’s psyche a “certainty of sound”.

I can actually say that the RS28CX offers recognizable musical performances with an evident naturalness and without any listening fatigue.

Its voice is peculiar indeed, but nevertheless close to reality.

I inserted the preamp in my system using two different power amps: the solid state Pass XA 30.5 and the valve state BAT VK 55 SE (this last one with RCA/XLR adapters), with my faithful Martin Logan SL3 speakers, which are extremely revealing of what is up-line of my system, and the Naim CD5X digital source with its FlatCap 2X external audio power supply.

The pre analog stage has been tested using the Lyra Lydian beta cartridge interfaced with a Jensen step-up with a transformation ratio of 1:10. It gives a congruous gain without mortifying the dynamic qualities of the Japanese pickup, which reads a load impedance of 470 Ohms: in my opinion the best impedance with this cartridge.

The line stage of the Leben shows great neutrality, with a typically valve-like low range, that is quite soft and not very fast, never overfull or gummy, definitely in line with the entire range.

Timbrically, there is a wide openness of the mid-high range, with the high frequencies very “flat” and fine-grained as a high rank machine deserves. This preamp is a fine chisel, a gear that can entirely represent what the source send to it and, substantially, an excellent and transparent “tuner” of the entire system.

Everything with the Leben seems to find its place with balance and great naturalness.

Voices are never artificial or with a timbric deviation. All the sonic characteristics reach a ground made of sound truth, whether there is a sax or a string quartet.

Lots of dynamics but without strains or unnatural accelerations: all flows with no effort and very close to the live performances, exactly how our ears expect to listen to.

With small ensembles, jazz or classic, there is the capability of catching punctually the single instruments -that are very well defined and sculptured - the excellent air of the scene and the concrete tone that gives back the sounds with intimacy.

A hearing pleasure without any listening exertion.

The great class comes out with more demanding programmers' where many competitors turn their elevated detail into stridency and their marked dynamics into continuous and not very homogeneous strains.

The Leben keeps its naturalness instead, without losing control and musical coherence: briefly no breathlessness.

If you get some problems in pumping up the volume, which becomes less pleasant with the increasing of the level, you should listen what happens with the RS28CX. It does not modify anything with the varying of the potentiometer. It simply reproduces it louder.

The harmonic content is of a high level and the instruments are never affected or without vitality. You feel like listening to the finest reproduction of something real, palpable and solidly tangible.

Sometimes it is just a touch, an echo or an intonation, or maybe a sense of realism hardly describable, but with this preamp, you can listen to the humanity and the truth of the recording.

The remainder, made of frequencies, dynamics and detail comes afterwards.

The phono stage is timbrically "softer" than the line stage, more personal and warm in the midrange and a bit more valvelike, in a classical meaning, in the low frequencies.

The Lyra cartridge has a good control on the low range and is very synergic. Therefore, it would be advisable to pair any pick-up with similar characteristics, avoiding those “very mellow” and slightly dynamic. However, is better to avoid them, ever…

The midrange becomes warmer, agreeably euphonic, even if in a correct and measured way.

It is like catching a bit of romanticism in your set-up. I mean, that afflatus we are always seeking when we are trying to assemble very good analog systems and that the Leben expresses with velvet decision.

Beautiful indeed the top range, extremely polished, measured but well extended, in short musical.

I realize that with a record by B.B. King recently bought in London on a stall, which is definitely poorly recorded, but with the Leben seems more listenable as it fixes the critical and sharp mid-high frequencies and the little homogeneous high frequencies.

This Leben seems to be the therapy for every audiophile disorder.

With the classical music, the correct tone, never aseptic, makes every score enjoyable, with very good transparency skills.

In the Beethoven Symphony No 9 (Karajan, 1962, Deutsche Grammophon), you can clearly perceive the expressive power of the first movement, as well as the poetry of the third or the exaltation of the fourth.

The strings, in this recording a little sour, are given back with rare mastery as the sound came from the rubbing of the bow on the string, from the contact of the materials.

The same clear impression with the Four Seasons of the Solisti Veneti (RCA), were the soloist has a sureness of touch but the instrument is never unnatural or without harmonics.

In short, with every kind of music the Leben is able to amalgamate your feelings with the chosen music, both with the distort notes of Hendrix and the genial intuitions of Mozart.

Also the treatment of the voices is exemplary, maybe the best thing the Leben can do, thanks to its harmonic truth which turns every word into reality.

I am stunned by the beauty of Suzanne by Leonard Cohen or by the pitiless desperation of Strange Fruit by Lady Day.

The sibilants are totally without grain and as happened with the strings, also here, is clearly perceivable the “physical” origin of the sound, that is the vibration of the vocal cords, the air emission of the diaphragm.

Same sharp certainty with the winds, where the sensation of the air insufflated in the instrument is clear, with the intonations and small mistakes that every musician can do, also the best ones.

Definitely extraordinary.



The Leben is a universal preamp, both for the boasted high gain and for the possibility of adapting the output via the rear switch if it has to drive a very sensitive power amp.

Both Pass and BAT amps felt very comfortable with it, and they expressed their best.
With a more airy preamp, the Pass would have given an outcome too unbalanced in the midrange, whilst a warmer mid-range, jointed to a more vigorous low range, would have given, with the BAT, a tone not very homogenous.

The Leben has driven these different power amps with correctness and extreme musicality.

I think there are on the market more transparent or dynamic preamps than the Leben, others more engaging and airy, others more solid in doing bass.

All these qualities are present in the RS28CX but are wisely and exclusively interpenetrate in a music machine that achieves the goal of bringing you to the core of music, forgetting all the rest.

It can fully solve your doubts and perplexities and realign your head with the wish of emotion.

It can divert the system from every straining or excess, taking away insane thoughts about cables and diabolic accessories and let you think only of Music.

Need something else?




top score ***** stars

Tone colour ****1/2 | Correct, with a warm mid-range and a very broad and determined mid-high range. Very enjoyable.

Dynamics **** | Indeed realistic and without splits, fluid and controlled.

Detail **** | High without unnatural efforts in the perception of the secondary details

Clearness**** line ***1/2 phono | High level, mostly the line stage, less the phono stage.

Image **** | Realistic and never afflicted by a wide-angle perception. More developed in length than in width.

Rise time ***1/2 | Quick impulses, mostly in the mid high range, less in the low range. Descent fronts never sudden or flat, also for the consistent harmonic content.

Manufacture ****1/2 | Great level with air wiring embellished by the separate unit. Standard equipment with NOS tubes. Excellent and personal look.

Price/quality ratio ***** | Extraordinary if compared to the musical performances and the included phono stage.


Official technical specifications:

Tube Complement: 2 x 6CG7 (G.E.); 2 x 12AT7 (G.E.); 1 x 5Y3WGT

RIAA Curve; <0,3 dB

Gain phono: 20,2 dB

Input: 400 mV (2KHz)

Gain line: 25,2 dB

Output: 80V

Output Impedance: 580Ohms

Weight: kg 13,5 (main body+ power supply)

Official Italian dealer: to Audio Point Italia website

Official current price in Italy: 6,840.00 EUR

Associated equipment: to Paolo "Miracle" Di Marcoberardino's system




Dear Mr. Castelli, Mr. Rocchi,
Thank you very much for your nice review on Leben RS-28CX.
Your evaluation is just hitting a thought of Mr. Hyodo.
Mr. Hyodo was willing to sell RS-28CX as an independent apparatus(not as a set with a power amp), RS-28CX was designed to match with several power amps regardless to its sensitivity.
Another point of this preampamp is the phono stage.
As you clearly indicated, in order to bring a full capability of CR-type/Non-NFB phono equalizer, Mr. Hyodo decided to have a separate power supply.
Therefore, we do not have any extra comments to your perfect review.
Thank you very much.
Yoshi Hontani, Managing Director


by Paolo
Di Marcoberardino
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